Limits to solar efficiency?

The efficiency of solar panels can still increase a lot.

Cambridge physics professor David Mackay is scientific adviser to the UK Department of Energy and Climate Change. In his online best-nonseller Sustainable Energy – without the hot air, page 39, he thinks we are already at the practical limit of PV efficiency:

Typical solar panels have an efficiency of about 10%; expensive ones perform at 20%. (Fundamental physical laws limit the efficiency of photovoltaic systems to at best 60% with perfect concentrating mirrors or lenses, and 45% without concentration. A mass-produced [photovoltaic] device with efficiency greater than 30% would be quite remarkable.)

Accordingly his scenarios assume 20% panel efficiency for residential and 10% for utility. That’s till 2050. In 100% renewable scenarios, the volume of solar is constrained by total roof area and competing land uses. So if you could plug in a higher efficiency, the limits shift too.

The DECC online scenario calculator uses 10% PVefficiency load factor and apparently 20% efficiency throughout. This is plain wrong. [Update, correction: I confused efficiency and load factor. See endnote]. In SRoeCo Solar’s online database comparing 12,622(!) panels, the median panel at position 6,311 has an efficiency of 14.50%, and only the bottom 3% are below 10%. The best panel is at 21.57%.

Here’s why I don’t believe Mackay’s 20% (or SunPower’s 21.57%) is a limit.

There’s a huge amount of research going on into solar PV, in many different avenues. I looked for innovations which:

  • enhance efficiency, not simply reduce costs,
  • look reasonably close to marketable products,
  • use cheap not exotic materials and straightforward methods of fabrication,
  • build on silicon, the dominant technology today.

Why the last condition? The steep learning curve for solar PV – 22% cost reduction for each doubling in volume – makes the course of the industry strongly path-dependent. Polymer cells, say, would have to beat today’s silicon module costs (60-70c$/watt) before getting any market share at all. Nobody’s going to stake polymer PV the €120 bn FIT liability it took Germany to get silicon down to this price. It would need to emerge from the lab at 50c/w, which is extraordinarily unlikely. It’s this mechanism that has kept concentrating PV a market curiosity and a financial black hole.

Here are four horses that look good to me.

1. Light-trapping channels

microgrroove Californian company Solar 3D has a scheme to gouge precisely shaped channels or pits in the surface of silicon panels, to trap more light, and light from more oblique angles. They claim to achieve 25.47% internal efficiency, and a much bigger gain in daily power output because of the wide-angle performance. The grooves can be made by etching, a standard method in the semiconductor industry.

This photo is not from the company, which is keeping its precise design a secret.





2. Aluminium nanodots
nanostudsNicholas Hylton of Imperial College London (et al) have a simpler idea to achieve the same result: deposit a Lego-style pattern of tiny 100nm aluminium dots on the top of the silicon or other PV wafer. He started with gold, but aluminium in fact works better. The dots bend light by quantum effects, trapping more of it in the semiconductor where it can give up its energy. Hylton claims a 22% gain in efficiency, say from 20% to 25%, but gives no information on the possible output gain from wider trapping angles.












1 and 2 seem to be alternatives. But I can’t see why they should not be combined with the others.

3. Perovskite thin-film

Perovskites are a class of crystals similar to the naturally occurring calcium-titanium minerals first found in the Urals in 1839. Michael Grätzel at Lausanne has championed the use of synthetic perovskites for PV, and has reached 15% efficiency.  His perovskites “have the formula (CH3NH3)PbX3 with X being iodine, bromine or chlorine”; they are deposited on a thin layer of titanium dioxide, the white in white paint. None of these elements are scarce (the lead is a worry). Another British team at Oxford – Henry Snaith and Michael Johnston, a fellow of my old college – have managed to get the same efficiency without any fancy nanostructures, merely with vapour deposition – another standard semiconductor technology. This brings perovskite cells into the realm of potential mass production.

Perovskite-solar15% is amazing for a new laboratory technology; it’s much higher than the 12% or so of production thin-film modules, which have benefited from years of improvement. By itself, it would still have a hard time catching up with silicon, and thin-film is overall slowly losing market share. However, perovskite films have a trump card: they are transparent. This means that in principle they could be combined with silicon.

Since they absorb light in a different part of the electromagnetic spectrum to silicon, the two materials might be used together in so-called tandem cells in which a silicon device would be placed underneath a perovskite one. “Here, the perovskite top cell would absorb higher-energy photons and the lower-band-gap silicon the lower-energy ones,” explains Johnston.

He did not guess an efficiency for the tandem cell, but his cannot be the only team trying to make them today to find out.

Two-junction cells of this type escape the Shockley–Queisser theoretical limit of 33.7% for an ideal single-junction p-n cell. They are not fantasy. Panasonic and others already make panels with a layer of amorphous silicon on top of monocrystalline silicon. SFIK these are not true two-junction cells, but they show that multilayer fabrication is commercially as well as technically possible. Johann Harter, the COO of the very big Austrian solar developer Activ Solar is “a strong believer in thin-film on silicon as a potentially strong solar option in the future”.

4. Graphene conducting sheets
graphene structureAnd just in time for multilayer cells come transparent graphene conducting sheets to take away the electrons knocked loose. Unlike perovskites, graphene is easy to grasp: simply a flat hexagonal mesh of carbon atoms, the 2D version of buckyballs and nanotubes. Marc Gluba and Norbert Nickel in Berlin

grew graphene on a thin copper sheet, next transferred it to a glass substrate, and finally coated it with a thin film of silicon. … Even though the morphology of the top layer changed completely as a result of being heated to a temperature of several hundred degrees C, the graphene is still detectable.

Graphene is a fantastically good conductor. Their next problem is soldering bigger conductors to something one atom thick …


horse_teeth2Can you combine these? My WimTech® module would have the nanolego – it looks cheaper to fabricate than the grooves -, then the perovskite cell, then the graphene conductor to take away the juice, then a conventional 20% monocrystalline cell. Would it work? Could I get 35% efficiency? Would it be reliable? Can I keep fabrication costs in the same range per watt as plain silicon? (I can charge a small premium per watt, as with mono silicon today, because higher efficiency lowers BOS costs per watt.) Dunno, dunno, dunno, dunno. But there are many dumber ways of betting €10m on a really high-payoff idea.

Now you should not buy any horse from me, however shapely its teeth. There may be hidden problems with these ideas that will prevent their reaching mass deployment; and if not, they may be overtaken by swifter runners. I’m not asking you to believe that these specific innovations will bring more efficient panels.

The argument is that if I, an amateur searching using my patented method of filter-feeding on a few cleantech blogs, can easily identify four promising routes to overcoming Mackay’s limit, then there must be many more out there. The professional and economic incentives to find and deploy solutions are very, very strong: Nobel Prizes and fortunes. So they are much more likely to happen than not.

My predictions for 2023:

1. Technical progress in solar cells will be sufficient to maintain the learning curve in PV module cost, bringing it to ca. 25c$/w. (The production costs of the leading Chinese manufacturers are already down to 50c$/w today.)

2. The efficiency of good-quality mass-produced (not niche) panels will go up from <20% to >30%. This will help the (slower) reduction in BOS costs, most of which are proportional to panel area not power.


A couple of closing data points.

The net installed cost per watt of residential solar PV in Germany has fallen below $2/watt (€1.450/w).

An updated chart of global solar installations, now back on their long-term trend curve of 44% growth per annum (data sources EPIA, pdf Global Market Outlook for Photovoltaics 2013-2017, page 13, Figure/table 1, and trade forecasts. Spreadsheet.)

Solar PV installation trend

Correction 8 November:
David Mackay emailed me:

You are confusing two completely different things: “efficiency” and “load factor”. […]
The load factor of UK solar farms is 10%; that is correct. And that is what the 2050 Calculator is talking about. Load factor is ratio of average output to peak output. That is completely different from the efficiency. Efficiency is the ratio of electricity out to sunshine in.
The efficiency is only relevant in the calculator when we show the area occupied by panels in the “Map” view.
I am pretty sure that we assumed an efficiency of about 20%, and we probably assumed that it increases.

The post is corrected to reflect this. It does not affect my argument about the upper limit.
Return to post

Postscript 11 November

For a really far-out scheme, there’s this:

Playing pop and rock music improves the performance of solar cells, according to new research from scientists at Queen Mary University of London and Imperial College London. The high frequencies and pitch found in pop and rock music cause vibrations that enhanced energy generation in solar cells containing a cluster of nanorods, leading to a 40% increase in efficiency of the solar cells.

Very fortunately, this does not work with the cells in current panels available today. You have to root for it never becoming competitive.

Author: James Wimberley

James Wimberley (b. 1946, an Englishman raised in the Channel Islands. three adult children) is a former career international bureaucrat with the Council of Europe in Strasbourg. His main achievements there were the Lisbon Convention on recognition of qualifications and the Kosovo law on school education. He retired in 2006 to a little white house in Andalucia, His first wife Patricia Morris died in 2009 after a long illness. He remarried in 2011. to the former Brazilian TV actress Lu Mendonça. The cat overlords are now three. I suppose I've been invited to join real scholars on the list because my skills, acquired in a decade of technical assistance work in eastern Europe, include being able to ask faux-naïf questions like the exotic Persians and Chinese of eighteenth-century philosophical fiction. So I'm quite comfortable in the role of country-cousin blogger with a European perspective. The other specialised skill I learnt was making toasts with a moral in the course of drunken Caucasian banquets. I'm open to expenses-paid offers to retell Noah the great Armenian and Columbus, the orange, and university reform in Georgia. James Wimberley's occasional publications on the web

98 thoughts on “Limits to solar efficiency?”

  1. If I recall correctly, the medium-grade panels on my roof right now are ~16% or so. They’re Siliken 305-watt panels… looking online it appears that 15.7% is the top of the range for them. We considered SunPower 20% efficient panels (which at the time I think was their max), but the additional expense didn’t seem worth it.

    Anyway, I’d challenge the “typical panels are 10% efficient” given that we hardly went with the bargain-basement option and are at ~15%.

    1. Though to be fair, he uses 20% for residential, which is higher than ours.

      Eh, who knows? The efficiency of the panels has been creeping up, up, up. I suppose it’s possible to hit a wall, but I’ll believe that when I see it actually happen.

      1. 20% is a high figure for today. But MacKay’s and DECC’s purpose is to map scenarios to a sustainable future for the UK out to 2050. The crucial assumption isn’t the starting point, it’s the expected rate of improvement. Near-zero is not credible.

        1. Yup.

          Also, I’d figure that utilities would have higher real-life efficiency than many residential setups. My panels sit on my roof. They’re not often in the perfect alignment to the sun for max efficiency. A utility (or commercial installation) might have a tracker array that squeezes more from the panels. Maybe he accounts for this, I dunno.

          Heck, my residential installer tried to talk me into a tracker array. For a couple of reasons, I didn’t go that route, but I’ve seen several other tracker units go up in the area. The owners are getting more from their panels than I’m getting from mine.

          1. As I recall from the advice here (about 50 degrees N, temperate maritime climate– outside London UK) it was suggested I go for the (more expensive) polysilicon because it is more effective on cloudy days when the light is diffuse.

            So it may not be as complex as a physical tracker, but simply changing which type of panel you install.

            Commercial installations I have seen don’t track. Looking after all those servomotors etc. would be a big installation and Operations & Maintenance cost (O&M).

          2. I’ve never quite understood the resistance to using tracking. Since all panels need
            to point the same direction, it would seem simple to do them all with one motor with
            a screw-gear reducer, and simple bulletproof mechanical linkage. That looks like
            maybe $200 of hardware, at most, roughly a few hinges and a garage-door opener,
            for 1D tracking. 2D would be harder, but I think that might be overkill (and maybe
            you could do it with a monthly manual adjustment ?).

            For ground-level solar farms, Google had a neat scheme using water and floats and
            a really small pump. Having the same water level across a row ensures they all
            move in sync.

          3. The nice thing about aiming with water is that you could readily create hybrid panels (PV and thermal), which does double duty. The hot water is useful for reducing energy use/cost and cooling the PV panels keeps them operating more efficiently and longer.

      2. why would utilities be satisfied at 10% efficiency? Are the 20% panels more than twice the cost, now and forever more? Even in a world where the maximum efficiency is capped at 25%, I’d envision the lower end panels getting closer to the peak panels.

        1. ” Are the 20% panels more than twice the cost, now and forever more? ”

          Given installation costs, even twice the purchase price for twice the power would be a good thing to do.

          1. ah, the Rob in CT comment about tracker arrays makes sense for utilities, and why they may lag in raw efficiency.
            Tracking arrays are going to be more mechanical things that can break, adding to the maintenance cost.

            It might never be cost effective for a plant in the Mojave to install moving parts, if land is just crazy cheap.

        2. First Solar, the only really big company still in the thin-film business, makes a good living in the utility market. The average efficiency of its panels is only 13.3%, but its cost per watt is competitive with silicon. In parts of the world where land is cheap like Saudi Arabia that’s all the customer is interested in. Japanese and Anerican householders may be more concerned with maximum power from a limited roof area, so that’s where SunPower sells its premium 21% monocrystalline modules. The Pentagon and NASA will pay silly prices for 35% triple-junction cells for satellites and SEALs, the equivalent of $500 brass hammers. IMHO there will always be a spread of efficiencies selling into different customer tradeoffs, but it doesn’t matter. My question was whether the mean will rise, which does.

          1. NASA pays for the 35% premium because the cost of lifting the mass to orbit (and beyond!) dwarfs the cost of the panel.

            I’m guessing the spreads will narrow (outside of niche markets like NASA), so the mean rises without any breakthroughs.

          2. If you work with explosives, you need an expensive brass hammer that doesn’t cause sparks. I didn’t mean to suggest these things are a waste of money in their specialized niches.

  2. An interesting and useful post. I would be interested in seeing something similar on the state of the developing art in battery technology/energy storage generally. This has always seemed to me to be the laggard of the industrial revolution, and progress continues to be less rapid than one would hope. Many important technologies will work better sooner with improved energy storage, including vehicles, but none more so than solar energy, which uses the most pervasive but most decisively intermittent source there is.

    1. I’ll keep an eye open. But don’t hold your breath. It’s quite hard for an amateur to get any sort of handle on a field like this. There’s a flood of boosterish press releases; on the other hand, the comparative surveys tend to be late and conservative.

      Remember that there is a perfectly good and well-established technology for large-scale grid storage: pumped hydro. Japan already has 25GW, more than the US total of 21GW, and ten times Britain’s measly 2.5GW. So the storage need is for batteries closer to the consumer. I’m not worried that this nut won’t be cracked, as electric vehicles have reached a market scale where the quite capable car industry has strong incentives for steady improvement. That’s without the good bet by Chu to give priority to battery research.

      Good car batteries will carry over to cheaper home storage. This will be fun to watch, as self-consumption will rise to the point where many homeowners and businesses will be independent of the grid on many days of the year. The utilities hate net metering now, batteries are their nightmare.

      1. Pumped hydro storage is great – especially because the cost scales mostly with
        the peak power of pumps and turbines, but the capacity is just how big and
        deep your reservoir can be. Unfortunately suitable terrain for big deep reservoirs
        with narrow dams is fairly rare, so it isn’t obvious that this solves the problem.

        As for cheap home storage, I’m still a little skeptical about battery-based storage,
        since the batteries so far are still very expensive, the lifetime is limited,
        and in any case almost any form of in-home high-capacity energy storage is likely
        to pose some risk of fire, explosion, or release of hazardous chemicals.

        It would be great if we had a cheap dense storage capability big enough to get through
        a couple of dark cloudy days and nights. But even that wouldn’t really solve the
        problem that in northern latitudes we get a lot more insolation in summer than in
        winter. That is somewhat alleviated by the fact that peak usage is caused by
        air conditioning on hot sunny days, but is still an obstacle to solar taking over
        a really big chunk – say over 50% ? – of generation capacity.

        1. Is it really impossible for the USA or Britain to match the Japanese rate of pumped hydro? In the US, the problem is geography – the middle of the country is flat. But there are a lot of Rockies and Appalachians. The upper reservoir doesn’t have to be huge.
          The seasonal variation is an argument for wind, which complements solar seasonally. Charts for Germany. Since solar has a steeper learning curve, there will eventually have to be differential subsidies for wind.

          1. James — Mackay does consider that question in his book. It’s one of the reasons he believes in nuclear power.

            The problem is we’d be flooding Scottish or Welsh valleys, and kicking Scots and Welsh off land they have grazed for generations– for English benefit. In the fragmenting environment of the United Kingdom this is not the 1950s when we built Dinorwig when presumably we just paid the calculated compensation and went our merry way.

            Undersea links to Norway and Iceland offer more potential (although I am sure the Germans have their eyes on that as well).

            In the US long distance DC is possible– they use it in Quebec (and Russia) for example. So pumped storage in the Western Cordillera or the eastern mountain ranges, with wind farms in the middle, would work. It would require a coordinated national programme, and that sort of thing has proved hard in recent years. The USA is not the country now that put the first man on the Moon, nor built the Interstate Highway System. Nor built the first atomic bomb.

          2. The Scots haven’t grazed the glens “for generations”. Many poor farmers were turfed off the land in the 19th century, often by their clan chieftains, to make room for sheep. The Highland Clearances were a tragedy, not on the scale of the Irish Famine – the peasants didn’t starve – but a tragedy and a scandal all the same. The Highlands are a melancholy if beautiful heather desert, kept that way for grouse shooting by rich foreigners. The Scottish government is using its newly gained measure of self-government to mark out a policy that’s much more favourable to renewables than London’s. Wind farms don’t produce many jobs, but they do create some, plus a stream of rents and local taxes into the Scottish rural economy. I bet they’d welcome pumped storage projects too.

          3. I agree the solar/wind combination is technically good. Of course the economics get tricky since
            both solar and wind are capital-intensive, and having enough capacity of each to cover the
            low-output time of the other would raise the overall cost. That is aggravated by the possible
            need for a high-capacity power going to different regions – in the USA, the best solar sites are
            in the Southwest, while the best wind conditions are in the north. If you also need fossil
            capacity, or hydro storage, to cover times when both solar and wind have low output, then it
            gets even trickier.

            I think a large part of the solution is in conservation and improved efficiency – we’re just
            scratching the surface of what can be done with LED lighting, smart appliance controls, and
            high-efficiency DSP-controlled permanent-magnet motors. And we don’t have a smart grid yet,
            which could allow demand management to align with solar+wind output.

            Anyhow, on the general point that efficiency is likely to increase and costs are likely
            to decrease, I share your optimism.

          4. Nothing is “impossible” – some things are just too expensive to make sense.
            You need a decent-sized deep natural basin, with a narrow enough outlet
            to allow you to build a small cheap dam. And it helps if it’s close either
            to the power source (wind or solar) or to the consumers, so that the capital
            cost of building transmission lines will be small. It also helps if there’s
            enough rainfall and a big enough watershed to fill the basin naturally in a
            reasonable time – you’ve probably got good terrain in parts of the Southwest,
            but it would be a challenge to fill it (and keep it filled) with water.

            You’d have to get deep into the details to figure out how what the power/cost
            curve would look like. But since hydro-electric power is a rather mature
            technology, I think a lot of the *best* sites in developed countries were already
            taken decades ago – though I guess adding pumped storage to an existing
            hydro dam could work out well.

            All in all, it’s a good piece of the puzzle, but I wouldn’t view it as
            a clear general solution to the energy-storage problem.

          5. James

            Losing on the indent here. I take the point (I was thinking of Welsh farmers as I typed it and Dinorwig is in Wales).

            Just in our NIMBY modern Britain though, can you really see us flooding some big river valleys in Scotland and Wales to give us the necessary pumped storage? Maybe you can do a deal with a Scottish landowner, but don’t you think the various walking associations etc. would give us hell? Recall their opposition to windfarms for spoiling the view from the Cairngorms National Park?

            It is worth trying. And we might get 1-2 GW. 5 GW? I think that’s stretching it. And I would say 10GW, say, is impossible (plus the power lines to get that out: *that* really will put the fat in the fire).


            Beware the rebound effect. It’s significant. Both at the commodity level (have more electric gadgets, run them for more hours) and at the general equilibrium level (go on holidays abroad with the money we saved on lightbulbs).

            You never, in energy efficiency, get anywhere near the efficiencies achieved that engineering analyses (bottom up) suggest are possible. That’s the problem with the McKinsey curve etc. Journal of Economic Perspectives had a special issue on all this.

            The general assumption that electricity use per unit of GDP gets about 1% pa more efficient is a good one. Probably we can force this to 2% with some strong measures. More than that? Would require a ‘Battle of Britain’ style crash programme like Japan is going through post Fukushima– and they are pushing the limits of that. I *cannot* see Americans turning down the air con in a heat wave in the national interest the way the Japanese are prepared to do. And the Japanese have already changed all their lightbulbs– you just don’t see/ hear of the grand wastes of electricity that Americans engage in in Japanese companies or homes.

          6. valuethinker: on the rebound effect, I don’t think it’s as bad as you’re making out.
            I’m not seeing people sleeping with the lights on all night just because they
            changed from incandescents to CFLs. Nor running their refrigerators at 34F instead
            of 38F. And businesses are even less likely to indulge in that kind of waste: a
            large supermarket 5 miles from here was recently rebuilt from the ground up, using
            all-LED lighting, high-efficiency refrigeration, and a gas-powered combined-heat-and-
            power unit. That kind of change makes economic sense and is going to be widespread
            over the next decade. And, as I said above, smart controls are just arriving (e.g.
            the Nest thermostat) and the smart grid isn’t here yet. Also the particular
            field I work in – computing – has seen massive improvements in power efficiency over
            the last 5 years, which seem set to continue. Back in 2004, desktop cpu’s were
            using 120W all the time – now, with much greater capability, they run on 65W max,
            and average a lot less than that – and smartphone/tablet technology pushes that
            down into the sub-5W range.

            So I’m hugely optimistic about conservation and energy efficiency, and anticipate
            that a dollar invested in conservation will offer much higher gains than a dollar
            invested in wind or solar capacity for the foreseeable future, though in a less visible
            and less glamorous way.

          7. Richard C

            I urge you to take a look at the Jrnl Econ Perspectives on this.

            The canonical 100% rebound effect was insulation of council houses in Britain. Turned out that almost all of the improvements in efficiency got eaten up in higher room temperatures. That is probably a peculiar example– as you would know, the average council house in 1968 say was *cold* (the average British living room was 12 degrees C, then, vs. 19 degrees C now).

            Estimates range, but the direct effect is c. 30%. People don’t necessarily leave the lights on any more, but they have *more lights*. Or look at Vehicle Miles Travelled, which were on a steady rise with only small blips for the oil crises (until about 2006, when they have flattened, which might be the sign of something).

            It’s the indirect effects (general equilibrium) which are large. Save money, go on more holidays to Ibiza in the Balearics.

            Computers is an odd example because although power consumption has become a serious issue eg in data centres (over half the lifecycle cost is electricity I believe) total power consumption by the IT industry has kept rising, because demand growth from the internet, cloud computing etc. is still exponential.

            What strikes me is that whilst total energy consumption by household in the UK is down c. 1/4 since 1998, that’s in the context of a more than doubling of gas and electricity bills– pretty inelastic. Especially given that households have fewer people than they did (ie what we are gaining on per household, we are losing on numbers of households). And the low hanging fruit is gone– most UK houses now have *some* loft insulation, and ‘A’ efficiency boilers (ie condensing with a secondary heat exchanger) are probably the majority, and most houses have some double glazing. Insulating the walls will be a far trickier business– there’s a huge political row on about who will pay for that (it’s tacked onto consumer energy bills right now, the obligation on the energy companies to help poorer households improve efficiency).

            You could argue that the UK is uniquely bad– but therefore it should have the highest returns from energy efficiency spend. And I know houses built in North America in the 70s and they are *not* energy efficient– R12 walls and leak traps (this is in Ontario). Energy consumption per household in Ontario is a *lot* higher than in the UK (primarily, but not wholly, climate).

            I agree with you something like the Nest could be pretty important in that it is ‘behaviour change’ without asking people to do anything different, or to sacrifice comfort.

            But I caution you, and it’s well documented in the literature, that the ‘energy efficiency paradox’ is well understood by economists. Engineering based micro studies show the US, say, wastes 30-50% of its energy consumption– hence that lovely McKinsey NPV curve with all those negative numbers (ie costs less to save money than you save on an NPV basis). But economists understand very well (see Paul Joskow’s comments for example) that those improvements are never achieved. The transactional and informational costs of implementing them seem just too high.

            Even on the industrial side, where one would think there are no economic barriers, no split incentives (landlord v. tenant), the most energy efficient solutions just don’t get adapted (although far more here than in any other sector).

            As I say, we will get -1% pa just out of normal economic progress. We can probably push that to -2% pa, so if the economy grows by 2%, energy consumption is static. (Dieter Helm is good on this though, and has a chapter in ‘The Carbon Crunch’ summarizing the energy efficiency argument– to some extent we have simply outsourced our primary energy consumption to China and other manufacturing powers).

            But there’s no vast reservoir of energy efficiency improvements out there, that we are likely just to implement. Yes if we do another energy crisis and price of energy doubles (from current levels) we’ll get another surge like the early 1980s. There was a lot of easy stuff in that though, for example closing oil fired power stations (and replacing them with coal). But for North America, natural gas prices have gone the *other* way, and although UK gasoline prices are twice yours, we don’t get twice the fuel economy (and we drive less in part because it’s a small place).

          8. Richard C

            Journal of Economic Perspectives January 2012 It’s available as a free PDF if you google it. Endlessly interesting stuff.

            Also Resources for the Future has some good stuff.

            When I did the switch to LED lightbulbs I discovered I had over 50 lightbulbs in the house. I doubt my parents had 20 in their (larger) house. So even in a technology that is so unambiguously good and energy saving (I am ignoring environmental waste in creation– about which I just haven’t checked) you can see the problem. And we have 6 computers (not all plugged in at any one time, and some are laptops). My household electricity consumption is about 20% less than the UK average.

          9. Richard


            Allcott, Hunt, and Michael Greenstone. 2012. “Is There an Energy Efficiency Gap?” Journal of Economic Perspectives, 26(1): 3-28.

            DOI: 10.1257/jep.26.1.3


            Many analysts of the energy industry have long believed that energy efficiency offers an enormous “win-win” opportunity: through aggressive energy conservation policies, we can both save money and reduce negative externalities associated with energy use. In 1979, Daniel Yergin and the Harvard Business School Energy Project estimated that the United States could consume 30 or 40 percent less energy without reducing welfare. The central economic question around energy efficiency is whether there are investment inefficiencies that a policy could correct. First, we examine choices made by consumers and firms, testing whether they fail to make investments in energy efficiency that would increase utility or profits. Second, we focus on specific types of investment inefficiencies, testing for evidence consistent with each. Three key conclusions arise: First, the evidence presented in the long literature on the subject frequently does not meet modern standards for credibility. Second, when one tallies up the available empirical evidence from different contexts, it is difficult to substantiate claims of a pervasive Energy Efficiency Gap. Third, it is crucial that policies be targeted. Welfare gains will be larger from a policy that preferentially affects the decisions of those consumers subject to investment inefficiencies.


            Like you, I can see the inefficiences (the US just looks like this extraordinary energy sink, ditto Canada, compared to other countries). But when you dig, it’s not at all clear that there is something irrational or easy to fix going on here. And when you start thinking about the General Equilibrium issues (the holiday in Ibiza with the money saved problem) then one starts to become much more of a sceptic about efficiency.

          10. valuethinker: thanks, I’ll check out that Journal of Economic Perspectives.

            I do indeed remember growing up in a house at 60F, with frost inside the
            single-pane windows in the morning.

            But coming at this from the computer industry (I think we have 8 computers
            and 6 tablets in the house 🙂 I really think there are opportunities for
            revolutionary reduction in energy usage with no loss of comfort or
            convenience. The move from a 100W+ desktop to a sub-5W tablet is one example:
            datacenters are catching up as well, both with new x86 cores specifically
            optimized for throughput/watt, and with ARM-based microservers exploiting
            advances from smartphone/tablet devices.

            Semiconductor technology also gives us LED lighting, which is still rapidly
            improving; efficient high-power semiconductors for motor controllers,
            solar inverters etc; and really cheap low-power microcontroller/DSP devices
            which allow smart controls. We’re also getting new smart cheap sensors
            from cellphones and even gaming systems (e.g. the Kinect controller)

            Put this together with a smart grid and I think you can make some quite
            magical advances. A thermostat that can get the GPS data from your cellphone
            to know when you’re on your way home; can check the weather forecast to
            anticipate changes; turn off the upstairs lights when the house is empty.
            All the technologies exist – they just have to be integrated and made in
            volume and marketed smartly. But that could happen quickly, as it did for

          11. The general equilibrium/holidays in Ibiza question is interesting.

            But I’m finding the widespread adoption of smartphones to be an
            inspiring example: smartphones don’t use much energy, compared to other
            computing/information access devices. But nobody buys a smartphone as
            an energy-saving device; and probably few people save money by buying
            a smartphone (and a $60/month phone+data contract). They buy a smartphone
            because it makes their life easier, and maybe also because it’s a status
            symbol and a lifestyle accessory – the fact that it’s energy-efficient
            is barely noticed. Then once you have the cellphone in your pocket,
            you’ll use it to check email because it’s quicker and easier than
            waking up the desktop or laptop.

            And I think that’s the way that energy-saving improvements have to be
            marketed to consumers: not as some bad-tasting medicine that will be
            unpleasant but will save money; rather as something beautiful and
            helpful and lifestyle-enhancing that’s worth paying a bit extra to get
            because it makes your life easier.

            Those are also the same reasons why people buy $25K cars instead of
            functional, but uncomfortable $14K cars, and the same kind of marketing
            is used. On the whole, $14K economy compact cars these days work
            just fine, but they’re noisier and less pleasant to drive and have
            less room for luggage and passengers and cheaper materials.

            If we can market it right, people will pay *more* for the nicer appliances
            and controls, and houses, that happen to be energy-efficient. And they’d
            be happy with the result, and wouldn’t have any substitution effect because
            they wouldn’t have any more money in their pocket, in spite of the savings.

            That seems to be the Nest strategy, and I hope it works. But I’m also
            curious what economists have to say about the rapid widespread adoption of
            smartphones (and the expensive iPhone in particular).

          12. Revealing quote from the article “Is There an Energy Efficiency Gap ?”

            … nearly half of investments that engineering assessments showed would
            have short payback periods were not adopted due to unaccounted physical
            costs, risks, or opportunity costs, such as “lack of staff for analysis/
            implementation”, “risk of inconvenience to personnel”, or “suspected risk
            of problem with equipment”.

            These sound like feeble justifications to me, the last two in particular
            being precisely what I would expect an energy efficiency gap to look like:
            businesses finding weak excuses to stick with the status quo because they
            just aren’t interested.

            The authors however, take this as evidence that the energy efficiency gap
            is illusory. But that’s economists for you: their discipline tells them that
            people are rational decision-makers trying to take economically optimal
            decisions, so when people make a decision that appears stupid they tend
            to assume the existence of hidden factors. But sometimes a stupid decision
            is just a stupid decision.

            The answer, I think, is that the equipment which provides greater efficiency
            must also provide other benefits which make people’s lives easier. For
            businesses, that might be improved monitoring and accounting and prediction
            of energy usage, or maybe lower maintenance costs (e.g. long lasting LED bulbs).

          13. […]
            Annual electricity costs at the 177,413-square-foot warehouse dropped from about $50,000 a year to less than $5,000, and ComEd awarded Raymond a $65,176.90 efficiency rebate.

            Today, Raymond walks under a cool, white glow in Warehouse No. 5, extolling those lights with the intimate reverence typically reserved for the latest smart phone or luxury car. Forklifts beep past as he strolls through rows of boxes filled with the empty plastic bottles made in an adjoining plant. Twenty feet above his head, networked clusters of light-emitting-diode (LED) bulbs brighten as he moves near them and dim as he walks away.

            Energy efficiency: How the Internet can lower your electric bill: Energy efficiency – revolutionized by cyber networks – may carry the same impact as a new oil boom. Electricity users are seeing power in their ‘negawattage’ as they cut their bills by 90 percent.

          14. Richard C

            I think what is important here is the observation that these supposed energy efficiency measures are not being adopted.

            Whether the consumers and companies know why is moot. I know why my office does not use LED lightbulbs in place of halogens in the corridors and lifts (1. split incentive problem, we would fork out, the other tenants in the building would benefit; landlord has no incentive to make building more efficient because tenants (on long leases) pay the bills 2. capex freeze so tight that spending a few hundred quid on lightbulbs with a sub 24 month payback is verbotten).

            The fact is the McKinsey type studies imply that there are these huge energy efficiency gains out there, ‘money on the table’. And yet they don’t get snapped up.

            Which means that there are adoption barriers there that are real costs to consumers.

            This gap between what engineering studies show is possible and what is actually achieved is absolutely crucial to the whole energy efficiency debate.

            California, which along with Japan is probably the global pioneer in energy savings, has shown you both what can, and cannot be achieved with energy efficiency. The headline number (that Californians use 40% less electricity per capita than other Americans is misleading: California has dry heat (less need for AC) and it has larger households (and so less per capita)). Best estimates are that Californians, after 30+ years of energy savings programmes and regulations, are c. 17-20% more efficient in their use of electricity per capita than Americans as a whole.

            And yet I still struggle with people on the internets who refuse to believe that their 25 year old fridge is costing them $20 pcm in electricity (c. 180 kwhr pcm for a pre 1992 fridge). And when fridges are replaced, they wind up being used as beer fridges, or given or sold to poor people– so they are still out there. Ghana has had to ban the importation of old fridges, the problem is so bad there (another economic concept: Ghanaian consumers are highly capital constrained).

            The other problem is the one Dieter Helm points out. The presumption that we will have rising energy prices is only that, a presumption. With the rise of shale gas the price of energy could *fall* from here, as it did in the 1970s.

            And the largest single mechanism for energy efficiency, the price mechanism, then falls apart. See the US SUV market in the 1990s.

            In sum, we never get out of energy efficiency what seems to be possible from an engineering viewpoint.

          15. Re: “Which means that there are adoption barriers there that are real costs to consumers.”

            I think you’re making a leap there that isn’t justified by the evidence. Stuff like
            “risk of inconvenience to personnel” is a really flimsy excuse. And my interpretation
            would be that there are emotional and psychological barriers to making energy-efficient
            technologies, but not necessarily “real costs”.

            And I keep coming back to the rapid adoption of iPods and iPhones as an instructive
            paradigm: there were portable music players before the iPod, but people stuck with
            CD players; there were smartphones before the iPhone, but they weren’t a mass market.
            The technology existed. But someone had to package and market it in a way that generated
            an emotional and psychological attraction strong enough to overcome the emotional and
            psychological barriers to change. Once that’s figured out, radical change can take place
            astonishingly quickly – the whole massive smartphone industry has grown from practically
            nothing in less time than it takes to build a nuclear power station.

            An economist assumes that people aren’t doing it because there are “real costs” which
            somehow are not captured or quantified by the economic analysis. I assume that people
            aren’t doing it because just because they need a bit of sugar-coating on the medicine.

            Now, if you can show me an economic analysis from 2004 or so which predicted the
            imminent arrival of the smartphone industry, then I’ll start to believe that
            economics gives us a good handle on the future. But until then I’m inclined to think
            that economists are much too keen to make the assumption that what happened in the past
            will continue into the future. And I think that’s a bad assumption when dealing with
            the convergence of rapid technological advances.

            The other part of the puzzle, of course, is to make inefficiency really hurt, by imposing
            a steep enough carbon tax that people notice it. But I’m not optimistic about the
            chances of that happening in the USA any time soon (maybe after 2020 when Texas turns

          16. Richard C

            On the carbon tax, the level you would have to get is so high that it’s not politically feasible (and would be massively economically disruptive).

            Carbon taxation pays off because a couple of industries have a high marginal propensity to substitute. To wit, the electric power industry, which will switch heavily from coal to gas. The aluminium industry which will relocate where it does not have to pay the carbon tax (or just reduce output). Air travel? The effect will get lost in the wash– fuel price swings far larger than the equivalent carbon tax have had little apparent impact on demand for air travel.

            If you look at other payoffs, such as the Corporate Average Fuel Economy rules (and EU equivalents), the cost per tonne CO2 saved is over $100- -they are massively inefficient ways of achieving the same goal. (note that generally however vehicle drivers are price insensitive. Short term elasticity of gas (petrol) prices is estimated at c. 10% (double the gasoline price, consumption falls by 10%) and long term 30-70%.

            The typical paybacks demanded in industry and commercial settings are 30-40% IRRs (payback of 2-3 years at max). With home energy improvements, households show a similar preference. Note households also do things which are *irrational* eg double glazed windows over insulation (payback on double glazed windows in the UK is over 20 years, ie longer than the expected life of the windows). Or rather, households do home improvements for aesthetic and comfort reasons *not* for energy/ cost savings reasons. (If you Youtube UCL energy seminars (University College London) there’s a video from 29th October about a survey studying just this problem).

            I agree there is a ‘tipping point’ effect with consumer products.

            However the examples you cited are examples are ones where the product generated significant new benefits for consumers, which are not necessarily monetary. The products are easier to use, they bring ‘music everywhere’ etc.

            That is not what is the case with energy efficiency– it’s a grudge purchase at best. There are always issues with taking inter country data on these things, but the UK, roughly, has twice the energy prices (domestic gas and electricity, petrol) of the USA (depends on which state: Connecticut has close to UK power prices, California has higher) and lower incomes. Yet we don’t have wonderfully efficient houses– anything but.

            In economic terms the income effect is drowning out the substitution effect. Energy prices are just not a big enough part of American household budgets (except gasoline prices, and even then you still see a lot of very big cars and SUVs) to induce significant energy savings measures, against all the other barriers to adoption: dislike of new light bulbs, cost/ hassle/ difficulty of new insulation etc. I still find myself arguing on the web with people who have the *choice* whether to have oil or natural gas, whether they should switch (! surprisingly, a lot of New England/ NY doesn’t have natural gas connections). Or whether they should get rid of a 25 year old fridge. Compact Fluorescents is of course a political issue- -that’s a left wing conspiracy, don’t cha know ;-). To the extent that people confuse mercury/ CLF etc with LEDs.

            You have, I think the technologist’s idealism about this. I share that (father was a utility engineer) but I also know the limits — I’ve seen that in practice too many times. Again, Dieter Helm’s The Carbon Crunch (worth a read to get a sensible sceptic’s view about what we are not doing about global warming (he’s not a denialist)) is very good on this.

            *Why* people say they are not adopting is not terribly relevant (no one wants to write ‘because this place is so badly run that we can’t even do what we are supposed to do let alone worry about conservation’ even if it is sometimes true). The fact is *they do not* adopt energy savings measures, even ones with quite high IRRs. So we have to conclude the costs of so doing are greater than the anticipated rewards. Industrial processes that’s the least of a problem (because industrial companies make their profit margins by shaving costs 10 basis points here, 5 basis points there). Commercial organisations and final consumers much more so.

            Economists call that a ‘revealed preference problem’. Why we say we do something may have nothing to do with the real reasons, and what we do (spending real money) is always a better signal than what we say. By and large we do not pursue energy conservation opportunities, either as individuals nor as organizations (industrial processes I think are the major exception).

            Some countries (Sweden, Japan) have made pretty heroic efforts to do something about it. But even there, institutions matter. The Swedish gas network is municipally owned, and awful, and that has driven energy conservation efforts whereas the UK one is modern and efficient (but the UK is where we hit the rebound effect hard: the average temperature in a UK living room has gone up over 6 degrees C in 30 years). Japan they have built energy saving into the culture (but what they have not achieved, even in light of Fukushima) tells you the limits.

            There may be ‘tipping points’ out there. LED lightbulbs come to mind (in that they provide an equivalent service to consumers, at a far lower lifetime cost– and they don’t have the light issues of CFLs). Again data centres, because electricity is such a huge cost (but conversely they get relocated to low power price districts: Google in North Carolina, etc.).

            All I can say is that you should be cautious about the macro possibilities for energy conservation. It’s there, and it’s real, (consider California), but it has limits and those nice McKinsey curves just don’t happen. An economist would tell you that means there are significant hidden costs/ barriers to adoption.

          17. On the carbon tax, “massive economic disruption” is the point!

            But the transition costs can be reduced by ramping up the tax (on a
            pre-determined and cast-in-stone schedule) over a long enough period
            that people don’t actually have to scrap much brand-new capital
            equipment. Probably 5 years would be about the right ramp-up time
            to influence purchasers of cars and water heaters and refrigerators.

            It’s not going to happen with the current US politics. But it should.

            CAFE is a stupid policy, which also results from the same broken US
            politics (one party is 100% dedicated to the principle of no new taxes,
            and roughly 1.3 parties are dedicated to satisfying big donors who got
            big under the status quo and don’t want change). It’s better than

            I do have the technologist’s idealism: but then I work in a field that
            has seen many orders of magnitude increase in capability, and decrease
            in cost and power intensity, in my 30-year career. And I’m especially
            optimistic because seminconductors and cheap low-power computing (plus
            cheap sensors) would also appear to be highly relevant to many of the
            problems in power generation, power distribution, and power consumption.
            The same forces – and some of the same people – that put a smartphone in
            your pocket are going to put something neat on your rooftop and in your
            thermostat and appliances. If I knew *precisely* what it’s going to be,
            I’d be doing it myself 🙂

            And the key, as we agree, is making it something other than a “grudge
            purchase”. CFL’s really suck – who wants a light that doesn’t actually
            turn on right away when you hit the switch ?? LED’s, on the other hand,
            work instantly, give good light, and you (almost) never have to get up on
            a ladder and change them.

            So I think “why” people don’t make investments is actually very very
            interesting indeed. Because once you can figure out what the real
            obstacles are, you can address them directly: you don’t want to pay upfront ?
            fine, we’ll put the panels on your roof for nothing and take a cut of the
            savings; or lease them to your business. You think they look ugly ? We’ll
            make them in colors that match your old roof. It’s boring ? We’ll put a
            beautiful gizmo on your wall, and let you show pretty graphs on your iPad.

        2. Richard C

          Needless to say I am a sceptic of the costs-benefits of smart metering. I think the evidence shows you get early improvements in consumer behaviour, and then lose that. The UK is going to spend £400-500 per customer on smart meters by 2020 and I doubt it’s going to show a huge improvement in behaviour.

          The reality is people will come home, put on the lights, put on the cooker, put on the kettle and watch East Enders. Regardles of whether those kwhr cost them 10p or 20p. Only the very poor will respond significantly. I am watching this all happen in Ontario and I believe people are not radically changing their behaviour (but the political uproar is entertaining to say the least– watch what the next government does).

          Total consumption of electricity is unlikely to fall by much, and demand curve shifting might be on the order of 10%. Handy, given the wholesale cost of electricity on a day when the wind is not blowing, between 4pm and 8pm, but not decisive– in the UK context the output of 4 nuclear units (6GW/ 60GW peak). Again, the price elasticity of substitution (time shifting in effect) will be greater in the industrial sector (but they have shift workforces so not as large as one might think). The National Grid is actually going to pay NHS hospitals to run their diesel generators to provide power at peak times! Talk about unforeseen consequences!

          Smart Metering in other words might serve the needs of the grid (lower capacity margin at peak) but it’s unlikely to have a huge impact on total demand. We will still generate those kwhr. Depending on how your utility generates its electricity (and in the UK that will be mostly gas) it won’t have a big impact on total CO2 emissions (you’d have to have a CO2 free baseload, like Ontario’s CANDU reactors, and then really shift demand into the small hours of the morning, etc.– then you’d make a significant impact. But if your mid merit and peak power is all fossil fueled, shifting from peak to mid merit won’t cause a huge reduction in CO2).

          1. Oh, I agree with you that Smart Metering is not going to give us much.

            But the combination of smart grids and smart appliances becomes much more
            interesting. Take the dumb consumer out of the loop, and let the computers
            in the smart appliances, with knowledge from sensors and web-based predictions
            about future local conditions over the next week, negotiate with the computers
            in the smart grid, with their knowledge about current and future overall
            demand and the supply/cost curve and ramp-up time for various sources.

            In particular those grid-management algorithms can focus on minimizing
            the use of carbon-intensive sources (which of course they will want to do
            if there’s a significant carbon tax), and allow us to make renewables
            a larger share of the total capacity.

            Then I think you can get somewhere interesting. And that kind of
            convergence of technologies is just the kind of disruptive change that
            economics, with its focus on continuity and extrapolations from history,
            is ill-suited to predict or analyze.

          2. It’s also interesting to think about the successful selling of double-glazed
            windows, at high prices relative to the energy savings.

            I can suggest several factors:

            1) Replacing a drafty old window with a well-sealed new window offers
            more energy-efficiency benefit than a simple comparison on R-values
            would suggest: and even more comfort beyond that, since a cold draft
            feels even worse than it is.

            2) Radiative heat transfer has a significant effect on comfort – sitting
            next to cold single-pane window with ordinary glass, you’re radiating
            body heat directly to the exterior, which is a small loss of energy
            but coming directly from your skin it *feels* cold.

            3) Maintenance of wood/putty/glass single-pane windows is an enormous pain –
            condensation drips down and rots the wood, frames distort from temperature
            and humidity changes so you can’t open or close the window, and even in the
            best case the frames and sills need frequent repainting, which is tricky because
            you don’t want paint on the glass.

            4) Double-glazed windows have been aggressively marketed at least since the
            1960s, with prominent brand names, extensive networks of dealers and
            installers, and lots of television and print advertising. The emotional
            link “double-glazed = comfort” has really been bashed into people’s skulls
            (and that success of advertising is completely unrelated to whether it’s
            actually true or not).

          3. Note that the draftiness and radiant-heat comfort issues could probably
            be solved equally well by using about $100 of draftproofing supplies and
            a few cans of expanding polyurethane foam, plus an infrared-blocking
            transparent film on existing windows; rather than $800 per window or whatever
            it is that installed sealed double-glazed units cost these days.

            So I’m not suggesting that double-glazing is necessarily a rational way
            of getting that level of comfort. Just that the marketers and advertisers have
            done a good job of identifying a benefit that people really want (in an
            emotional way – being warm and comfortable in your own home is a classic
            emotional appeal that could have have come straight from a Don Draper pitch)
            and then getting people to pay a lot of money for their product.

            The branding and marketing and advertising is really important. I think
            rooftop solar PV in the USA will take a big leap forward when/if it’s picked up
            by nationally-known brands such as Ikea, GE, Samsung, Phillips and is
            heavily advertised.

  3. I’m sorry, James, but this seems like the exact sort of pettifogging that is engaged in when people encounter more or less undeniable results that they don’t like. (cf How many people “died” in Iraq? or What will be the EXACT consequences of global climate change?)

    What difference does it make? If 20% efficiency is infeasible, you seriously think something IMPORTANT changes even if we assume a doubling of that limit, to 40%?
    Mackay’s point is ultimately that solar energy is very very very diffuse. If you want to capture it through PV to create large amounts of energy (ie a wedge) it’s going to imply SERIOUS modification of the environment we live in. And throwing in prices doesn’t change that fact.

    1. The terrific thing about solar energy is that it really isn’t very diffuse – it’s about
      1kW per square meter. My house, with 4 occupants, uses about 20kWH/day, and has
      average insolation equivalent to 4 hours of full sunlight. So at 100% efficiency
      I would need about 5 square meters; at 20% efficiency I would need 25 square meters,
      or a square about 16ft x 16ft, roughly the area of one large room. That array would
      have peak power of 5kW. At 50c/peak watt, the cells would be only $2500. Even at the
      $2/watt installed cost seen in Germany, it would be only $10K.

      It’s even better if you can design to also use the solar energy directly for space heating
      and hot water.

      The “diffuse” criticism is only meaningful if you’re locked into the concept of
      large centralized power generation facilities. And even there, coal isn’t all that
      concentrated if you account for the land area used (or devastates) by mining; and
      nuclear plants are usually surrounded by a pretty big exclusion zone.

        1. Appreciating the CAVU notwithstanding, I have a MesoWest station near the house that measures insolation in W/m*m and today in mountain wave conditions it has varied from 634 to a current 204; yesterday from 10-2 in sct skies it was between ~475-615. Good summer days it will be over 1k as a point measurement. YMMV.

        2. I meant 1kW per square meter perpendicular to sun, and AFAIK the 1kW figure
          is about right at the bottom of the atmosphere (somewhat, but not vastly,
          less than the 1.4kW/sq m above the atmosphere). It’s much more than “a tenth”.

          Nobody puts solar cells flat on the ground, because that would be grossly inefficient:
          at worst, you choose a fixed angle and orientation to maximize the energy captured
          throughout the year; at best, you use 2D tracking to stay near the perfect angle.

          1. Most solar software out there today gives you the optimal angle for racking – e.g. mine is 38 degrees.

    2. Maynard

      Define ‘serious modification’? Solar farms in fields? Check. Although the US is a huge country. Solar panels on south facing roofs? Check. But is a WalMart massively more ugly because it has solar panels on it?

      Note your first two examples are pure rhetoric. There’s no connection with death rates in Iraq (you can google the debate). As to the EXACT consequences of climate change, anyone who claims they know is lying (at least to themselves). What we do know is that the world is likely to warm up a lot if we don’t alter our current course of emissions (which is pointing to 1000 ppm CO2 by end of century implying a temperature rise of 5+ degrees C) and that at previous times in history when the world was that much warmer, it was a very different place (forests at the Poles, end of ice caps etc.). We also know that we don’t fully understand the carbon cycle feedback mechanisms and they could seriously increase the effects.

      1. Let’s note also that open-cast (and mountaintop-removal) coal mines are quite
        “serious modifications” of the environment. And in many regions, deforestation
        for wood fuel. And the large exclusion zones around Chernobyl and Fukushima.
        So we’ve always been willing to contemplate big changes to satisfy our energy
        needs. Wind farms and solar panels on roofs seem much less disruptive and
        dangerous (and arguably less ugly) than those alternatives.

  4. And all this is even before you get into things like integrated PV/heat systems. The same multilayer manufacturing technology that works so nicely for PV stuff also allows you to get some decidedly non-black-body behavior.

  5. It would be useful to know which of the quoted “efficiency” numbers are for pristine newly-installed panels with optimum orientation, and which are derated for the efficiency losses that inevitably occur in real-world installation : mis-orientation, accumulated dirt and dust, scratches and loss of opacity in the protective cover, accumulated degradation of the semiconductors, etc.

    I’m guessing that the 10% number used in the DECC calculator takes all of those into account, in an attempt to give a realistic assessment of the power actually useable over the lifetime of the installation, and that’s why it seems so low.

    1. MacKay accounts for orientation separately in his online book.
      The standard panel warranty is 90% of nominal output to year 10 and 80% to year 25 in normal use. (I assume they are different where the panels face sandstorms.) Obviously these guarantees are conservative. Shawn Roe (he of the huge database) advises: “Realistically expect less than a 3% decrease in output the first year, and about .5% decrease per year after that for most panels”. So a panel initially at 15% could at worst decline to 12% by year 25, and following Roe to 13%. For a new 20% panel, these numbers would be 16% and 17%.
      No, you can’t get to 10% this way. Perhaps DECC have a nuclear white elephant to sell?

      1. The based on the assumption, I presume, that somebody regularly goes over them with a bottle of Windex and a squeegee? (Which is, I think, only fair: Why should you warrantee the entire system including dirt? You’ve got no control over the dirt.) Based on the gunk I had to power wash off every horizontal surface when I bought this house, a squeegee might not even cut it hereabouts.

        But I will honestly admit that assuming only 10% efficiency for solar panels seems somewhat tendentious. Solar power seems a subject where the tendentious is the norm, on both sides of the argument.

        1. Google studied this at one of their own Californian sites. Conclusion: horizontal panels should be cleaned regularly, it’s not worth it for tilted ones. No doubt wind and rain tend to wash dirt off a very smooth surface. Perhaps the scattering by a few dust particles compensates for the blocking. Anyway, Britain is rainier than California, so it’s unlikely the results would be any different there.

  6. There is I recall a physics limit as to the efficiency of solar cells.

    Around 65%?

    I’d have to look it up in a textbook.

  7. James, that’s the second time in a week you’ve written an article attacking DECC in which you’ve got a basic fact totally wrong by a factor of two by confusing two different terms. It’s hard to take you seriously.

    1. To be fair, I don’t think the DECC site is totally clear.

      Mackay is a good scientist though, and the DECC people are very professional. Policies have a political agenda, of course, but the quality of DECC output is usually good. And you have the Committee on Climate Change, which is independent and monitors the UK’s progress towards its legal target of -80% CO2 by 2050.

    2. Where on the DECC calculator pages do you find a statement that the assumed panel efficiency is 20%? I can’t find it. I learnt this from MacKay’s email, which I promptly published. Note that he’s only “pretty sure” of the assumption, not certain. A fully professional operation publishes and provides references for its key assumptions. IMHO the calculator should be rated as good work still in progress.

      My nuclear post didn’t mention DECC at all, so it can’t have misrepresented it. The calculator was raised by another commenter; I made a mistake in my response to that, and again corrected it in the thread.

      You are right that I’m not very trusting of complicated gadgets that claim to be very scientific but lead to conclusions rejected by every other OECD government and the generality of expert opinion. Should we be?

      I don’t ask you to trust me on anything. That’s why I provide links.

      1. James,

        So let me get this straight, you claim not to have attacked the Department of Energy and Climate Change in a post devoted primarily to presenting evidence to cast doubt on a decision made by that department, featuring a link to a BBC article in which the minister of state is quoted extensively, on the grounds that you didn’t use the phrase “department of Energy and Climate Change” or “DECC”.

        20% efficiency is on page IV.a of the Excel calculator (at the bottom of the disused filing cabinet behind the sign saying beware of the leopard etc.). I can certainly understand not being able to track this down, but it is in the model – you can also see that the modelled efficiency doesn’t increase over time. I agree with you that this efficiency should gradually increase over time, and that that is a flaw in the model.

        1. I claim not to have misrepresented DECC in the nuclear post, which was what I understood you to be charging me with. Sure I was attacking their decision, using data supplied by other sources, which you have not questioned.
          Thanks for locating the solar efficiency assumptions deep inside the spreadsheet (you have to run along the sheet tabs a long way). Sheet IVa confirms Mackay’s assertion that the calculator uses 20% efficiency; but not his suggestion that it rises with time.

  8. Backing up a bit here, the whole concept of “efficiency” doesn’t matter much for solar cells.

    It matters a great deal for fossil fuel-based generation, where the fuel cost is a large
    part of the levelized cost-per-kWH. But it hardly matters at all for most applications of
    solar power, because the sun is going to shine anyway whether you catch it or not. The
    cost-per-peak-watt is much more interesting: who cares whether you need to cover 30% of your
    roof area, or 50% of your roof area, with cells ? It doesn’t matter, as long as the cost
    is the same. Right now, it seems that racking and installation are absurdly expensive in
    the USA, which favors fewer higher-efficiency panels; but that seems like a problem which
    is easier to fix by a) smart mechanical engineering of the rack components; b) high-volume
    manufacturing of those components; c) standardized design to simplify installation; and
    maybe d) changing building codes to require standardized solar rack mount points in all
    new construction.

    Of course if we can reduce the boring racking/installation costs *and* increase the efficiency
    to get more output from each panel, then that’s even better. But don’t get sidetracked into
    thinking that “efficiency” matters for wind and solar the same way it does for fossil-fuel
    sources. Installed-cost-per-watt is the interesting figure.

    1. RichardC

      Here in the UK the efficiency *does* matter. I only have enough roof (south facing) for 1.1 kw and I live in what is for the UK a relatively large house (the average new home in the UK is 96 m2, mine is c. 150% of that).

      So in my quite typical neighbourhood of terraced (row) houses, doubling efficiency would double output, we already cram as many panels onto the usable space as engineering allows us to.

      In my case I decided the annual output (850 kwhr pa) just didn’t justify the installation– the Feed In Tariff would have made it profitable (say for sake of argument generation £500-600 pa on a $6k investment), but that is only c. 1/4 of my annual consumption.

      1. I should add, a solar panel that does twice that ie 1700 kwhr pa starts to look a lot more attractive.

      2. Well, kinda sorta. But from a global point of view, what it means is that your
        house is not a great place to put current solar cells. Much better to take the
        solar cells we can make at the moment and put them on south-facing rooftops,
        or solar farms, in the Southwest USA, or Spain, or Italy. It’s actually pretty
        astonishing to me (having lived my first 29 years in England), that rooftop
        solar could be economically attractive in the UK, which is quite far north
        and very cloudy as well (I especially remember one summer when it rained
        28 consecutive days – in July).

        And from that same global point of view, it’s better to produce 1.1GW of
        15%-efficient cells than 1.0GW of 25%-efficient cells, if the total cost is
        the same. And the fact that low efficiency would encourage us to put the cells in
        high-insolation sites rather than low-insolation sites is a feature, not a bug.

        Note also that what ultimately deterred you was the high installation cost –
        $6k for 1.1kW is about $5-45/watt. Drop that to Germany’s $2/watt and you
        would probably have bought it even in the cloudy UK.

        1. I used to think pv efficiency didn’t matter independently of cost, as you argue. Of course you are right that it doesn’t matter the same way as for technologies using scarce fuel – which includes current forms of nuclear as well as fossil. What changed my mind was seeing a guy as influential as David MacKay arguing that the maximum conceivable deployment of solar in the UK still won’t cover a major chunk of current energy demand. It’s become part of the case for Hinkley C. So solar efficiency affects the politics of the transition as well as the economics.

          This may be a Brito-centric view (see also valuethinker’s comments). Like Japan, Korea and the Netherlands, the UK has a large population living at a high latitude in a smallish area. The USA or Brazil have huge areas of lightly populated land with twice as much sun. Russia doesn’t get much sun, but it’s even emptier. China has empty spaces in Inner Mongolia for utility farms; and for rooftop, the big cities are further south.

          The UK could copy Japan and build giant floating solar farms. There are no NIMBYs on the Dogger Bank. You could (perhaps) grow mussels and scallops on ropes underneath, as they do in Galicia.

          1. Well, with all due respect to my country of origin, the UK is a rounding error,
            and I don’t much care whether it goes solar or not. If we can get solar and wind
            to take off in USA, Brazil, India, and China, we’ll have a chance.

            Besides, on the figures quoted, it seems that the real obstacle to solar in the UK
            at the moment isn’t low efficiency, but high installation costs in the $5/watt range.
            A bunch of very unglamorous work on simplifying permits and producing standardized
            low-cost rack systems and cheap easy-to-install inverters (I expect that 220V grid
            is a problem) would solve that without any fancy new semiconductor technology.

          2. Actually, the levelized costs of nuclear electricity seem to be dominated by
            the capital cost of the plant (and the end-of-life costs of decommissioning),
            so I think “efficiency” also isn’t so important there (though the volume of
            high-level radioactive waste produced per kWH might be quite a big contributor
            to cost, and somewhat correlated with the normal concept of “efficiency”).

          3. You seem to be implicitly worried that cost of land is a significant contributor
            to solar generation cost. That certainly would seem untrue for the southwest USA:
            you can get land, even within a few miles of a town, for about $3000/acre.
            An acre is about 4000 square meters. Suppose you can cover 25% of that with
            solar cells at a good angle that would be 1000 square meters of cells, with peak
            power of about 0.15 x 1MW = 150kW. So even at $1/watt, the solar plant would
            cost about 50x more than the land.

            I expect land in the UK, even in remoter areas like Cornwall, may be considerably
            more expensive, but probab;ly not enough to catch up with the cost of the solar cells
            and other equipment.

          4. Looks like farmland in Cornwall is around 10K pounds/acre, or $16K/acre.
            That’s still about 10x than the cost of installing solar cells etc –
            so I still think your emphasis on efficiency is inappropriate, even in
            (much of) the UK.

          5. James re Dogger Bank.

            You’d be amazed. We are getting significant kickback on offshore wind: 1. visual impact from the shoreline 2. maritime hazard. People don’t like change, especially not industrial scale change. That worries them more than another Fukushima.

          6. Valuethinker: “People don’t like change, especially not industrial scale change”. You may be right, especially for Britain, but industrial-scale change is the one thing absolutely guaranteed.

        2. Richard

          On your nuclear point. I urge you to read the Charlie Stross piece ‘Nothing like this will ever be built again’ on his antipope blog — I linked to it in the nuclear thread. Because of high moderator temperatures (I think) the Advanced Gas Reactor is 10% more efficient than other nuclear reactors, and that makes it another Concorde– a piece of pretty, and useless, technology due to cost reasons. In fact Concorde cost the UK Exchequer something like £5bn, and AGR over £30bn, one of the most spectacular financial disasters of the postwar years (did I hear someone say ‘High Speed 2’ for the Triple Crown? ;-)).

          Fuel is such a small cost in a nuclear reactor (about 10% of lifecycle I believe) that whether you use 30% or 40% of the primary energy produced is irrelevant.

          Waste cost is, for the new British nukes, to be added on top of every kwhr generated– there is a sinking fund for decommissioning. Because of the miracles of NPV/ Discounted Cash Flow, it’s only a very small cost (1-2% of total) because we are only going to pay it 80+ years out. We shall see if future generations think we did our numbers correctly– the current decontamination of the UK nuclear industry is spiralling towards £100bn cost (those Magnox reactors were uniquely good at producing radioactive waste)– funded Pay As You Go by the taxpayer.

          1. Thanks for the links. The continuing (though currently very tenuous) existence
            of the nuclear industry exemplifies the triumph of hope over experience.
            Nuclear cost estimates (and risk estimates) have almost always been notoriously
            over-optimistic …

          2. Richard C

            ‘triumph of hope over experience’ re nuclear.

            It represents the second half of the 20th century military-civilian nuclear complex. Nuclear power is a centralized solution, and that’s how Insul (US) and the Electricity Board (UK) built the grid.

            The system is constructed to favour high tech centralized solutions, and you cannot get more so than nuclear power. If you ever read AE Van Vogt’s Empire of the Atom/ Wizard of Linn (really a retelling of Robert Graves’ I Claudius) you get this atomic priesthood maintaining the nuclear reactors long after the core scientific knowledge has been lost in a war. We’ll need to look after these things for the next 10,000 years–an astonishing hubris.

            The alternatives such as wind and solar will of course also require huge centralized investments: in energy storage, in continent spanning grids. But they do have a degree of decentralization in the actual production technology.

            What is notable about nuclear is that there appear to be no economies from learning. They don’t get cheaper as you build more– even for the French who did everything right (same design, multiple units built in sequence).

          3. Though I’m not a fan of nuclear in general, I did have the impression that France’s
            many-copies-of-same-design approach was somewhat cheaper. I’m not sure what figures
            I’ve seen to justify that impression though: and government accounting can be weird
            in various ways. Also construction of the next-generation Olkiluoto-3 reactor
            seems to be the usual way-behind-schedule way-over-cost mess …

  9. There’s also a psychological effect in play here: it seems you turned down an
    investment with about a 12% ROI (500 pounds on $6K) mostly because it would
    have met only 25% of your total needs. An economist might view that as
    irrational, not wanting to eat one slice of cake because you can’t have
    two slices.

    1. Richard

      – efficiency does matter in my situation, and that’s not unique even to the UK– we don’t have big rooftops by North American standards, in much of Europe

      – on your Cornish fields that’s precisely where local objection has hit to large solar farms. Call it NIMBY if you will, but it’s quite real and there is some move to tighten planning restrictions. Remembering what has happened in Jersey (polytunnels for potatoes) this won’t be a UK only phenomenon (there are complaints about it in Ontario, btw)

      – a mistyping on my part– the cost was £6k (not $6k) so 8-10% pa accounting return (10 year payback, roughly). HOWEVER if you sell your house in the interim you may not get the full value (terminal value) of your investment back. So it is not quite the same thing as sticking £6000 into a stock investment. Since then I think the cost has come down (but most of the cost is not about permitting, it’s about the sheer hassle of scaffolding and installation) but so has the FIT tariff. I decided I wasn’t doing enough for the planet (about 500kg CO2 pa saved) to tie up the capital

      If you have lots of land, or lots of rooftop, or lots of direct sunlight (Emerging Markets), then cost is your sole driver. If you are talking shady mixed weather northern Europe, especially places like Germany and the UK, then efficiency does matter. And that I suspect will be true for any high GDP country. The US being slightly anomalous in how much land it has. Conversely in the NE USA where you have more Europe-like conditions, land and aesthetic values are high (in $ terms) and you are going to have the same issues about roof space, etc.

      1. Note if not clear. If I’d had the space for 2.5kw say, the price would have been something like £8k. The problem is the small roof form factor, NOT the cost of the silicon.

        Double the efficiency and this starts to look like an interesting play, even on my small roof.

        I don’t think I am being irrational, in that FIT will fall *but* efficiency *will* rise. So there’s an option value in deferring decision.

        £6000 at current ETS prices means I could retire something like 800 tonnes of CO2 from the European Trading System, for the same money as I could save maybe 0.5 tpa for 25 years = 12.5 tonnes from my rooftop. *If* I believe the ETS is a genuine saving in carbon emission (which I don’t at the current structure).

        I compromised and gave money to a rainforest charity. *there* I am sure I am saving tonnes of carbon.

        1. 8K pounds for 2.5kW is still an installed cost of $5.1/watt, which is high,
          many times higher than the panel cost. Beating down costs of permits,
          inverters, racking, and installation labor matters a heck of a lot.

          Agree with you about deferring the decision: that’s where I’m at as well,
          progress seems so fast that while installing solar seems good, waiting
          3-5 years seems even better.

          NIMBYism is always a problem (here in Massachusetts there’s a long-running
          fight about putting an offshore wind farm near Martha’s Vineyard).
          But it seems a bit crazy to apply it to solar PV, which is silent and
          clean – I’d rather be next to a PV farm than a pig farm or a coal-burning
          power station (I lived about 4 miles from one of those and could always
          see the huge cooling towers).

          My point about land prices was that even in densely-populated UK, the
          land price, though it’s 5-20x higher than the southwest USA, is not a
          big component of the cost of a solar PV farm. Based on those prices,
          you do in fact have “lots of land”.

          1. The comedian Grif Rhys-Jones was among those who protested against a solar farm in Dorset (or Cornwall?) and they got it stopped.

            So, rational or no, it’s here.

          2. Well, I’ll definitely accept that NIMBY opposition to any change is a
            problem. I would just distinguish that from the argument that the UK
            is too densely populated and doesn’t have “lots of land”. The land price,
            at 10K pounds per acre, shows that scarcity of land is not a big obstacle.

            I wish those NIMBYs would go and visit a few coal mines and coal-based
            power stations – I lived near this one (now defunct) as a child:

            and often heard it blowing off steam (from 4 or 5 miles away). Living
            near a quiet solar PC farm would be nothing. But that’s the UK – you can
            build any monstrosity you like in the Midlands and the North, but do anything
            near the weekend cottages of the London elite and you’ll have a big fight.

        2. The FIT falling is the best case. It may be abolished. I wouldn’t wait too long.
          Have you considered solar leasing, eg from Freetricity?

          1. James

            It’s a risk. However I decided doing something that was financially attractive, but had no real consequences for the planet (850 kwhr pa = 0.5 tonnes carbon pa, more or less, at current UK grid carbon intensity) was ‘Greenwash’. Increasing my mortgage at current interest rates was not a problem (and I’d earn a higher return than I pay in interest).

            Double the efficiency of the possible solar panel and I get interested, because that’s more or less half my annual electricity consumption.

            The challenge of how to insulate a Victorian house is one for the future– not even sure we’d get planning permission to change the external appearance. It’s certainly not cost effective (save we save 12000 kwhr pa that’s about 2-2.25 tonnes carbon pa; insulating the house externally would cost c. £10,000-15000; and there’s the interstitial condensation problem (the Germans know a lot about this, but British builders do not).

            Even where houses do have cavity walls, I suspect in running around filling them with foam we are building up the mother of a condensation/ dampness problem.

  10. RichardC

    (trying to beat the indentation problem 😉

    On French nuclear costs the Steven Thomas article introduces you to the issues and has cites:

    Even in France, where
    the huge programme of reactor orders from
    1970–1990 should have given every opportunity to
    take advantage of ‘learning’, scale economies and
    technical progress, the real cost of reactors more
    than doubled (Cooper 2010). The last four of the 58
    reactors ordered in that period took on average over
    13 years from construction start (first structural concrete)
    to commercial operation. A former Chief Executive
    of the French utility, Electricité De France
    (Roussely 2010) has acknowledged that while the
    reliability of nuclear plants has improved in recent
    years, in France, it has deteriorated. So experience
    with nuclear power seems to fly in the face of that
    with most successful technologies, where costs would
    be expected to fall and performance would improve.

    Cooper, M. (2010), “Policy challenges of nuclear reactor construction:
    Cost escalation and crowding out alternatives”, Vermont Law
    School, Royalton, Vermont,

    Thomas, S. (2010), The EPR in crisis, PSIRU, University of
    Greenwich, London,

    James Wimberley also had a post here about the lack of French learning efficiencies in plant construction. (It might have been Michael Hare?).

    1. I suspect nuclear construction, as an activity requiring a large amount of highly skilled
      labor, may suffer from Baumol’s Cost Disease. This would apply down the whole supply
      chain, since every component has to manufactured of high-grade materials to precise
      dimensions, subject to stringent inspection and quality control. That might be a
      large part of the reason why real costs doubled in France, even for very similar reactor

  11. RichardC

    On cavity wall and dampness, the jury is open. There’s a part of the UK (the west side, primarily) where cavity walls that are not insulated should just not be filled. But exposed houses in other areas may have the samem problem.

    I read the Green Building Blog (AECB) and I think it’s fairly clear that when it comes to interstitial condensation 1). the Germans know the most about it of anyone (the WUFI software modelling) 2). we still don’t know enough 3). the British building industry is lagging far behind.

    Our cavity wall insulation campaign could well come back to haunt us (and having done it, rectification is well nigh impossible).

    On the other energy efficiency points we have staked out a pessimistic/ optimistic position. I can only say from my time studying this area, that we don’t get the outcomes we ‘should’ be getting. There are very substantial barriers to adoption, not all financial.

    In industrial situations, where power is a significant cost, then I expect over time companies become pretty efficient. For example high voltage regulation equipment is making its way into the industrial sector (there are now home units, like the Vphase, but Which? (ie Consumer Reports) was quite negative on actual savings).

    Commercial enterprises its more difficult because electricity and gas are often relatively small parts of their cost base, billed by the landlord etc. However someone like M&S (or WalMart, which owns its own stores) this is a priority and they are making headway (UK shops still have open faced chillers though: the problem is chillers with doors they sell less). So there will be (as always with energy efficiency) a huge gap between best practice and average or worst practice.

    Home energy improvements the whole thing seems pretty logjammed, even in the face of very strong price signals.

    I don’t know that we can persuade each other, as long as I have made you aware of the economic experience on efficiency (and again I generally recommend The Carbon Crunch by Dieter Helm– Helm has a few axes to grind, but he is very well informed and a good economist; main criticism is he is one of the chief advisors to George Osborne (Chancellor) who authored the ‘dash for fracking’ and the ‘second dash for gas’ (generation)).

    Helm’s other point is, in light of what happened with fracking and US natural gas prices, that our assumption of strong price signals in the future to conserve may be utterly invalid. I don’t hold out much hope for an effective level of carbon pricing in the short term, or even the medium term. We will be forced to rely on regulatory solutions.

    Even though the tech industry has become massively more energy efficient, I do wonder whether total electricity consumption by tech has fallen. I suspect not: the increases in efficiency are racing explosive growth.

    Your many other points and insights are much appreciated. If I find any in particular that I think I can sensibly reply to, I shall.

    1. It has been a pleasure to discuss all this with you, and indeed neither of us is going to
      persuade the other. Your positions are consistent with the evidence from analysis of
      history; my optimism is based on – very possibly unjustified! – belief that the convergence
      of various technological changes, together with economic forces reaching a tipping point,
      can make the future sufficiently different from the past that historical evidence is a poor
      guide. I hope we’ll both be around in 20 years, sitting in comfortable solar-powered
      passivhausen, and googling the evidence with sub-microwatt in-eye supercomputers, to find
      out who was right 🙂

      PS thanks for the link to Stross’ AGR piece, that was blast

      1. RichardC

        It would delight me, too, to be wrong. Maybe I have acquired the habitual British pessimism ;-). ‘How are things?’ ‘Mustn’t grumble’. ;-).

        I am currently taking a course on climate change with physical scientists (geographers) who of course have no particular slant on economics or technology (I can also recommend the David Archer MOOC at Chicago based on his book ‘Global Warming: Understanding the Forecast). My head is thus swimming with CMIP5, RCP2.5 4.5 8.5 etc. (it replaces the old SRES scenarios of the 3th and 4th IPCC (A1B, A2 etc.) with simply imposing a forcing (ie the number is in watts/ m2) and then projects temperature and precipitation.

        What the lecturer noted is that carbon emissions since 1990 and Kyoto Protocols have nicely tracked the RCP8.5 scenario– ie the worst case scenario that we are prepared to entertain in our models.

        Now to a large extent that is about China (and I suspect, deforestation – the impact of the European biofuels standards on the world climate is likely to be one we have serious regrets about in 20 years). So maybe if the Chinese get on the bandwagon things will change (but there’s India behind them, and Vietnam etc.).

        Even in the West where emissions have been static or declined (not USA and Canada nor Australia) that has been about 1). prolongued slow growth 2). increased imports of manufactured goods from somewhere else (ie just shipping the problem offshore) 3). some greater penetration of gas v. coal (but the decline in nuclear more or less is offsetting that).

        So whatever we might do about carbon emissions, we ain’t done it yet. And show no signs of so doing. In the case of Japan and Germany (abandoning nuclear) we are going significantly backward. In the case of European biofuels, we have more or less set the house on fire (US ethanol is at least not contributing to deforestation, but it has other negative impacts– clean politics, dirty air).

        Charlie Stross’ novels are too crowded for my view. Not crafted enough. He’s in too much of a hurry. But his Laundry series (about a computer techie who winds up working for the ‘really secret’ British Intelligence service– the one that was set up to fight penetrations from the Cthulu mythos) is wonderful (his original 2 space operas, a series where he refuses to write any more because of the logical impossibilities created by his time machine– Singularity Sky and Iron Sunrise– were also really good). I wait (like everyone) with baited breath for the next Laundry piece. Each one is a pastiche or homage to a spy author. Len Deighton the first. Ian Fleming the second. Anthony Price the third. Modesty Blaise the fourth. Rule 34 (a police procedural set in a newly independent Scotland) starts with an armed robbery– in an online multiplayer fantasy world. You get the picture.

        When Stross puts his mind to it, though, his writing is excellent, and so is his mental creativity. China Mieiville is probably the most promising and ‘literary’ of modern British SF/ Fantasy authors (given the death of Iain Banks etc.) And it’s good news that Paul F. McCauley’s cancer appears to have remitted– brilliant socio-political interplayed around genetic technology. But Stross is up there for the quality of his ideas. (BTW both Stross and McCauley have twitter feeds that are worth subscribing to).

        And Paul Krugman has appeared at an SF con with Stross discussing the economics in ‘The Merchant Princes’ series. I mean, how good is that?

        1. On Krugman’s tastes.

          There is obviously this weird nexus. Over time one finds out that Krugman reads Stross (I think I discovered Stross separately). And he picked up an Alan Furst at a train station magazine shop, and became addicted and read them all (I know I discovered Alan Furst’s particular brand of pre WW2 Europe thrillers (based on Eric Ambler’s originals) separately).

          So there is some hidden correlation here amongst middle aged shortish guys who write on the internets– me and Paul Krugman, it is practically identical. I am waiting in expectation for the committee in Stockholm to recognize *my* contribution (whether in science, world peace or economics, or literature, I am fairly relaxed) ;-).

          I am sure if I can just triangulate one more Krugman taste, then the forces of correlation will get me my prize ;-).

        2. Thanks for the info.

          From what I read China seems to making pretty big efforts on clean energy – but
          also is so huge, and has such massive economic growth and improvement in
          GDP per capita, that reductions in carbon intensity can’t keep up. And of course
          telling a big slice of world population that they need to stay poor so that we
          can run our air conditioners is a bit disturbing.

          The political and diplomatic situation is certainly depressing. My hope is on
          technology and marketing and the apparent certainty that the rapidly falling
          costs of renewables will cross over the rising costs of each of the non-renewable
          sources – and of course forward-thinking investment decisions will anticipate
          that crossover.

          Thanks for the Stross info. If they put me on the Nobel committee you have my vote 🙂

          1. RichardC

            I would recommend Alan Furst as well, if you like thrillers. The later ones I am less impressed by, but his dense research and atmospheric settings show.

            If you like Stross you might well like Paul F McCauley, and as I say they both have fascinating twitter feeds. There’s no Nobel Prize in the Readership of Popular Fiction though ;-).


            His Quiet War in particular- -there’s a touch of a grownup ‘Ender’s Game’ about it. I also liked ‘Cowboy Angels’ about rogue CIA agents let loose in parallel universes to refight the Cold War.

            China. The problem is 2 fold:

            – they are workshop to the world. So our carbon pollution has become their emissions control problem

            – they are at that carbon intensive phase of takeoff economic growth– this is the domestic consumption side. Pouring lots of cement (5-10% of world CO2 emission is cement, and half of that was being poured in China). Steel. Aluminium (there are places with hydro electric powered smelters, but generally not China). A car market now larger than the USA (and still a fraction of the number of cars and trucks per capita).

            So getting all the comrades to switch to fluorescent lightbulbs (still not universally true, last time I was there which was a few years back), building wind farms (not necessarily connected to the grid) and throwing up solar panels doesn’t necessarily cut it. Note they are already the world leader in domestic solar hot water (something like 1/3rd – 1/2 of all the world’s installations in solar DHW).

            By all signs they have scaled back their nuclear ambitions post Fukushima. I think the discovery that some of their high speed trains fall off the tracks has set hares running re construction quality (I can attest to how badly built even some of their ‘luxury’ hotels are).

            If China makes moves on emissions it will be because of urban air pollution and the political issues that causes– in a sense they are retracing the steps the US and Japan went down in the 1960s re air and water pollution (economists call that ‘the Kuznets Curve’ after Simon Kuznets (whose main job was the first calculation of US GNP)– the tendency of richer countries to buy a better environment). It is now legal to import LNG into China (the government did not want states paying high import prices, previously) and so something of a switchover from coal for domestic heating is taking place (somewhere on the web there is an archive of smoke control photos from Pittsburgh in the 1940s– recently released; it looked just like a modern Chinese city’s pea soup). That will eventually have to spread to the giant bowl around Beijing, removing coal fired power stations (maybe just moving them further away) or replacing them with gas turbines.

            As Dieter Helm points out, the only real quick win with China (ie next 20 years) is mass conversion to gas- let’s hope they find lots of gas when they frack (always issues with the technology transfer from US companies, the Chinese don’t want to be dependent on US fracking companies).

            You get to technologies like Carbon Capture and Storage– but mass rollout of that seems to be decades away, the cost issues plus the nagging doubts about what happens when we stick it back underground, have made everyone less bullish about it than 5 years ago (a bit like nukes ;-)). Duke Power is in a right old mess at Kemper in Mississippi, and the Canadians have cut at least 2 major CCS projects due to economics. The Brits cannot even pick which project they want to subsidize.

            The irony of course that the main economic logic of CCS is to create a stream of pure CO2 that you can sell to the oil companies for Enhanced Oil Recovery at say $20-30/ tonne, probably hasn’t escaped anyone ;-). It’s a bit lke global warming accelerating our exploitation of Arctic resources ;-).

          2. The possible bright spot about China is that they have engineers in power,
            and a political system that allows them to take decisions and make stuff happen.
            One example is that in the current slump, China seems to be the only place
            applying truly Keynesian policies – and with very successful results.
            It’s a nice historical irony that Keynes’ policies, originally designed to
            make capitalism work well enough to stave off a Communist revolution,
            are now being used to keep a one-party (arguably-ex-)Communist government
            safe against the threat of a democratic capitalist revolution.

            Anyhow, this leads me to think that when and if the tipping point is reached,
            making renewable sources actually cheaper (as well as cleaner) than fossil
            fuels, then China will switch over pretty quick.

            Now if that only happens 30 or 40 years from now, it’s too late. But I think
            it’s sooner. And the Kusnetz curve will give a favorable tailwind.

            It reminds me a little of the old story about extrapolating from the number
            of horses on the streets of London between 1890-1910 and predicting that the
            whole city would be 3 feet deep in horseshit by 1930 … sometimes things
            change quickly, and I’m *hoping* this is one of those cases.

  12. Richard C

    I agree that we will probably hit a ‘tipping point’ when there will be a global movement towards cleaner technologies. Probably as the result of some very severe and noticeable weather events.

    My guess is we are at least 20 years away from that. We won’t try to save the planet (or at least the climate as we know it) until way way too late (relative to the changes that we have ‘locked in’ during period 1950-2030 say).

    What remains in the meantime is to chip away at it. ‘Quick wins’ like black carbon (Obama and China were talking along those lines). Trying to get coal fired stations closed, and prevent new ones being built (because once the damned things are built, sunk cost, there’s an economic rationale for running them for 50 years). Longer term energy R&D (like more efficient solar cells ;-)) eg Carbon Capture and Storage (utility scale plants).

    I really cannot see nuclear in all this because I cannot see us building say even another 480 power reactors (which would stabilize nuclear’s share in total electricity production at the current share– the reactors would be say 1300-1500MW ie twice the size of their predecessors, but of course demand would have risen). And I don’t think so-called ‘4th generation’ reactors (thorium, modularized pebble bed etc.) get us out of the boxes that nuclear technology places you in (particularly as the cost saving on the 4 Gen is about having no containment vessels etc.). The world might build another 100 reactors in the next 20 years, but 400+?

    BTW Scientific American (last month I think) had a piece on Russian reactors. The Russians are back in the game, and exporting. Let’s hope they have solved their quality control issues.

    So we will get to the 2030s and then it becomes the old Mad magazine poster: ‘Don’t Panic. Push Panic Button. Then panic’. As an older generation of Tony Abbotts et al. dies off (even the Koch brothers won’t live forever) we’ll reach a socio-political tipping point.

    Of course by then it may be too late. If you look at how dysfunctional the politics are of some of the key players are (USA, India, Australia, Canada etc.) are, it doesn’t make one hopeful.

    In an environment of budget cuts, not enough investment is being made into energy R&D. Once you strip out the spending on nuclear, which is a huge part of US DOE and UK DECC spending (dealing with the nuclear legacies) we spend very little on energy R&D compared to say bioscience or military or technology industries. This was something Stern highlighted and so has Dieter Helm- -and it’s gotten worse since the financial crash. Doing things like cutting the wind power production tax credit (PTC) and rediverting that money into R&D would yield very long term returns (don’t get me started on ethanol subsidies, or European biomass ;-)).

    On speed of change, Vaclav Smil gave an interview

    (I think he has also been in Yale360 magazine, longer interview, but couldn’t find it)

    His point is that energy source shares change very slowly. Since WW2 we have seen a rise in gas over coal, and a (with massive government forcing) emergence of nuclear for electricity. And that’s about it. The world’s energy sources are very similar now to what they were in 1946, say. This is the pessimistic view, but for all the growth in renewables (which now appears to be slowing down, as much was linked to government incentive programmes) that we have had in the last 15 years, they don’t register on the meter as a major source of energy. (other than preexisting hydro and biomass).

    Paradoxically more bad news on the climate, and particularly extreme weather events (which may not in fact be related to climate change, we just don’t know, and certainly cannot say with any confidence), *now* is *good* news. Because it might scare us sooner.

    You have to hope the human race will discover its collective survival instinct– because it is showing very few signs of it as yet.

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