Clean Power

Published on June 15th, 2015 | by Giles Parkinson


UBS Lays Out “Dream” Solar Scenario: 50% Of Global Generation By 2050

June 15th, 2015 by  

Originally published on RenewEconomy

Early this week we ran a report on the latest UBS analysis, which suggested that solar could displace both coal and nuclear energy as the world’s “default” source of power and could account for one quarter of global capacity and 10 per cent of output by 2050.

It turns out, however, that this was the investment’s bank’s “middle scenario”. In keeping with the global trend of underestimating solar, UBS concedes that this forecast could prove conservative.

“In cooperation with the MIT, we investigate the main constraints on “scaling up solar” (land, raw material, social pressure on tariffs) and conclude that solar could potentially power the entire planet without any land or material bottleneck,” it writes.

It presents four four scenarios ranging from low solar penetration (5% of global output), a mid-case scenario (10% penetration), a high scenario (25%) and a “Dream” scenario of 50%. (Click on table to enlarge).


“Taking our mid-scenario, we can see that the solar PV market could increase by 14 times from current levels,” the analysts write. “On this basis, global solar installed base would be 3,000GW, or about half of today’s total installed base (renewables as well as conventional) in the world, and 1⁄4 of the total capacity by then.”

The dream scenario would would lift total solar invesetment in solar from around $3 trillion in the mid scenario to $US14 trillion. It says there are no resource limits to silicon based solar panels, although there might be for thin-film modules because of restraints on the supply of tellurium, gallium and indium.

And what is the cost to consumers of these forecasts? Virtually nothing.

UBS estimates that global subsidies will could reach a peak of about €70bn in 2025, but would then begin to decline as older subsidised plants would leave room to newer and unsubsidised ones. As a reference, 2025 power bills would likely total about €6 trillion. That means the solar subsidies would be the equivalent of just one per cent of power bills at their peak (or 0.03 per cent of global GDP), and falling rapidly.

And the pressure on land resources? Not much.

UBS says one square km could fit 50-100MW of solar PV. “Taking the mid- range, we see that – on our base case 2050 scenario of 10% output penetration (25% of capacity) – solar PV would occupy almost 40,000 sq km, or 0.03% of the total land surface of the globe. Even under the “Dream” scenario of half of global production from solar, the covered surface by modules would be only 0.13%. “

Finance community, industry experts underestimate solar capacity growth

UBS says it wrote the report because it believes the financial community and most industry experts “largely underestimate the global solar capacity growth, as falling costs, supportive regulation and the opening up of new solar markets seems to go largely unnoticed.”

UBS expects large scale solar plants to become the industry standard, displacing centralised generation such as coal-plants and nuclear. Indeed, it expects solar could have as rapid a growth in global capacity as nuclear did in the 1970s and 1980s, but it expects no nuclear renaissance, because solar will beat it on costs.


Interestingly, UBS expects many of the utility-scale solar parks to find direct end customers in the business and industrial world. “Industrial customers, shopping malls or office buildings could be ideal clients, to sign a “fixed price” agreement, such as a PPA,” it writes. This is already occurring with the likes of Google, Apple, IKEA and Wal-Mart.


UBS says the impact of solar will be to transform the global energy markets. Countries will be driven by cheap costs, the removal of fuel price risk, and the benefits of energy security.

Solar, by 2020, will be the cheapest form of “new build”. Profit margins for thermal electricity (coal and nuclear) will drop to zero. Indeed, it says  availability-subsidies will be needed to avoid mass scale closures.


UBS says battery storage development will go hand in hand with solar, but while costs are likely to fall 75 per cent over the next decade, it cannot see a case for significant amounts of grid defection.

This, in turn, presents opportunities for utilities. It sees a $3 trillion opportunity in smart networks, and says utilities will dominate the rollout of solar, in contrast to developments to date where they have taken only a minor role.

“We believe that most of the “hidden value” in the utilities space lies in power distribution and in global renewable platforms (even though currently largely devoted to developing wind) as these will soon be converted into ‘solar springboards’ and fuel larger than expected growth.”


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About the Author

is the founding editor of, an Australian-based website that provides news and analysis on cleantech, carbon, and climate issues. Giles is based in Sydney and is watching the (slow, but quickening) transformation of Australia's energy grid with great interest.

  • Nick van der Wal

    Australia may be the first country completey powered by solar in 2040, since battery storage makes this possible.

  • Bob_Wallace

    That’s possible in Germany. There’s a problem doing that in the US, I forget the issue(s) at the moment. Perhaps how leaky our NG distribution is.

    • eveee

      Most U.S. And German pipelines new encounter hydrogen embrittlement at high H2 concentration. Hydrogen also leaks like a sieve. It’s a tiny molecule.

  • Bob_Wallace

    This is an enormous point –

    “Solar, by 2020, will be the cheapest form of “new build”. Profit margins for thermal electricity (coal and nuclear) will drop to zero. Indeed, it says availability-subsidies will be needed to avoid mass scale closures.”

    Five years from now coal and nuclear plants will (be/start to be?) unprofitable. Not just the least efficient, but all of them.

    Pinched off by solar and wind we may have to make decisions to subsidize existing thermal plants just to keep them operating while we build out replacements.

    Getting rid of coal by 2030 seems more possible.

    If you haven’t read it – recommended…

    • eveee

      Simple. All we have to do is keep subsidizing coal and oil like they are already.
      Oh, wait. They are losing money and going out of business even with that.
      I have a better idea. Skip the subsidies. Lets stop wasting subsidies on dead technologies like coal, oil, and nuclear.
      Lets drop all the subsidies for them and use 10% of that to expand renewables.

      • Bob_Wallace

        I wish.

        But what I think will happen is that we will continue to subsidized fossil fuels until they die away. AFAIK the fossil fuel subsidies are not time limited. They won’t come up for renewal. They’ll be allowed to linger on but at least the amount they cost us each year should decrease.

        Deep coal mining is dying out in the US. That means fewer black lung disease victims needing support and treatment. Less coal and less petroleum burned means fewer respiratory problems requiring treatment.
        I think there’s a decent chance we could get coal mostly shut down in the US over the next 15 years. That would be the end of coal subsidy, except for the lingering health costs.

        I suspect that we’ll be watching the rapid transition to electric transportation 15 years from now. Oil that isn’t’ extracted and isn’t refined will not collect subsidies.

  • Ryan

    For small government types, government investment in solar should actually be favored. Ultimately, decentralizing energy to the rooftop of individuals would drastically undermine government power. Imagine a scenario where no homeowner in America had to rely on the government to provide energy. The power of the federal government would be substantially reduced. Obviously, the downward sloping cost curve of solar would mean that any government subsidies would be short-term as the technology becomes more cost competitive on its own.

    Really a failure on the right to think about small government on a long-term horizon versus next year’s budget.

    • Bob_Wallace

      What home in America today is dependent on the US government to light its light bulbs?

      (TVA is a non-profit utility owned by the federal government. So, besides TVA customers?)

      • Ryan

        Every home in America except off-the-grid survivalists and Amish people receive their electricity from highly regulated public utilities, which is antithetical to so-called conservative principals. Unless of course, conservatives are not really about smaller government but really just about maintaining traditional forms of authority.

        • Bob_Wallace

          Grid regulation is largely a state function.

          Conservatives are mixed bag of cats. Some are corporate types who want to maintain profits for existing companies. Some are ‘tightwads’ who want to minimize their personal spending. Some have social/religious/lifestyle positions they want to force off on others. Some are concerned about national security, even to the point of paranoia. Some are libertarian types who are in favor of no rules for them, personally, as long as the ‘others’ are kept under control.

          • Ryan

            Conservatives are a mixed bag, for sure. But you just described Republicans, not conservatives. Conservatives believe that too much government – federal, state, or local – is destructive to a free capitalist society. That is not really in debate in philosophical conservative discourse. Hence, conservatives cutting taxes at all levels of government. The question is why would conservatives not support technology that will drastically reduce the power of centralized authority. Even if I cede the argument that conservatives=republicans who are a mixed bag, the next question is why none of this “mixed bag” supports solar subsidies. Really is a case of either short-term thinking or conservatives are distorting their true authoritarian beliefs for more palatable ones about less government. Giving them the benefit of the doubt, seems to be more a case of short-term thinking at the expense of a long-term progress.

          • Bob_Wallace

            I think the largest reason that conservatives/Republicans oppose wind and solar subsidies is because they’ve been fed the line that subsidizing wind and solar has something to do with the government picking winners and losers.

            I doubt many of them have any idea how many hundreds of billions in tax and insurance premiums we spend each year dealing with the health problems caused by burning coal. I doubt many of them know that nuclear has received far, far more in subsidies than have wind and solar. And I’d bet most think nuclear cheap and wind/solar expensive.

            I don’t think anyone has explained to them that subsidies work to help new technologies get on their feet. That subsidies are investments in our future.

            I think the largest problem is simple ignorance. If your information source is Fox or any other Murdock outlet then you’re going to be kept in the dark and fed BS.

          • Jenny Sommer

            Those are the same that believe that the German Energiewende will fail or has failed.
            They won’t even admit in 20 years that their then cheap solar, wind and renewable energy is a direct result of California, German or Danish policy of the last decades.

  • Formerly_Nom_De_Plume

    At some point in the article, it might be a good idea to explain what UBS is.

    • JamesWimberley

      Isn’t it easier to Google the answer (link) than to type the question?

      • Formerly_Nom_De_Plume

        I did Google the answer. But, you know, I probably shouldn’t have to.

        • nakedChimp

          You should get that Firefox add-on that automatically adds links to any acronym it finds 😉

    • Jenny Sommer

      I am surprised someone doesn’t know but I guess it would have been nice to mention it in a half sentence.

  • Here’s how banking kind of works: information is gold. A bank typically contracts out technical research. MIT for example. Work product is typically held tight. Meaning the information or results of the work isn’t disseminated out to the huddled masses. Work product that is disseminated out to us huddled masses is done so to sell us something. Stocks are a perfect example. There’s two piles of work product: one pile for internal use and one pile for everyone else.

    Nonetheless, solar will continue to grow. So will wind. That’s a good bet.

  • jessica Feinleib

    The UBS scenarios are already too low. They assume 1% global electricity from solar by the end of 2015. This mark was already hit only 5 months into 2015 so it will be higher by the end of 2015.

    • Richard Foster

      Yes, I expect 2% global by the end of 2016, 4% by 2018 and 8% by 2020 and then 15% by 2025, not the paltry 3% they’re predicting.
      If wind can keep growing (albeit a slowing rate), that’ll go from ~6% now to ~15% in 2025.
      Assuming the Hydropower capacity stays at around the 15% mark, then we’re close, if not over the 50% renewable electricity generation barrier by 2025. Certainly by 2030.
      Change is happening fast, much faster than anyone in the big corporations and thinktanks can keep up with…the only thing that can sabotage the revolution is obstructionist politicians (driven by FF lobbyists) and even then, I think if the rate keeps going for another 2-3 years, we’ll have reached a massive tipping point, if we haven’t already.
      After 2020, I can’t see anyone building a new FF powered power plant. Why would you, when solar PV will be half the price it is now and still falling…

      • jeffhre

        Meanwhile alternative energy, formerly known as fossil fuels, which are costly, hazardous, and depleting, seems to be staging a minor come back with the help of well paced politicians taking advantage of loopholes in the worlds energy distribution system rules, and low relative pricing.

        • Richard Foster

          Really? Given that more new renewable capacity was added in 2014 than FF, a trend that has already continued at a pace in 2015.

          New FF is declining. New Renewables are accelerating.

          Because our economic system is entirely now based on debt and future assets (especially in commodities), operating expenditure today is based on future profits, which is why coal companies are going bust as their profit margins narrow and then collapse. They have no future profits and so no current expenditure.

          Oil companies will follow and rapidly, because they are even more dependent on future profits.

          At least that’s my naive take on things.

      • Bob_Wallace

        Hydropower will almost certainly grow. Hydro is going to be a preferred fill-in for wind and solar as grids strive to become carbon free.

        The US could add a lot more hydro without building a single dam.

        10 GW could be added by converting existing dams.

        Oak Ridge National Laboratory (ORNL) has identified more than 65 gigawatts of untapped hydropower potential in US rivers and streams. Run or the river hydro.

        The same likely holds for other countries, plus many countries will build dams without worrying about environmental impacts.

        • Richard Foster

          Yes, I also expect hydro to grow.

          It’s further encouraging though that we will be >50% renewable than at the absolute latest 2030 (up from ~22% now). I’m still optimistic of being ~80% by then, given solar PV growth rate.

    • heinbloed

      Well said.
      The energy transition/Energiewende is in full swing, it is hard to make a prediction based on the past now.
      Everything goes much faster than previously expected by anyone.

  • jburt56

    Estimates depend critically on the extent of the electrification of transportation. Will autos be 100% electric by 2050? 80%?

    • Adrian

      Barely matters. Transport is 1/3rd of total energy, but that is measured as input BTUs. When we stop throwing away 70% of those btus as combustion waste heat it becomes only a 10% increase in electric demand. Done properly it is also dispatchable load, utilities will (eventually) be able to turn-down chargers when say, a/c loads are peaking demand. Drop 100,000 chargers from 10kW down to 8kW for an hour and free up 200MW for more critical loads…

      • Richard Foster

        Waste energy is only about 60% and that includes transmission losses. My (very rough) guess is that we need to replace 70-80% current FF capacity for electricity generation (that may be high), without including extra for energy already used for transportation.

        Don’t get me wrong though, I think it’s easily doable. And not by 2050, but by 2035-2040.

        Solar PV at 1% global now. 2% end of 2016. 4% 2018, 8% 2020-21, 15% 2025, 30% 2030-35

        Wind at 6% global now, 10% by 2020, 15% by 2025, 20% by 2030-35

        Hydro likely to remain constant (with new additions) at 15%, Biomass at 10% (already nearly there)

        Add in storage solutions, and you’re throwing away less solar PV and wind.

        Adding it up 30+20+15+10 = 75% of global generating capacity.

        And I think we’re close to reaching a massive tipping point – as soon as solar PV and wind are cheaper globally (and significantly so), there will be no reason to build FF power, except for vested interests….

        • Adrian

          Only Class 8 trucks and Priuses are in the 40% thermal efficiency range, and even those are just at steady-state interstate cruise. Idling, acceleration, city traffic, etc are all at much lower efficiencies. 25% average thermal efficiency for the US vehicle fleet is likely optimistic.

          I had my own math flub above, 30% of 33% total energy is about 1/3rd more electricity demand, not 10% more. Still quite feasible, and there is plenty of electrical end-use efficiency to be gained in buildings and industry.

        • JamesWimberley

          “Waste energy is only about 60% and that includes transmission losses.” In what country? The LLNL 2014 energy flowchart fir the USA (link) gives 25.8 quads wasted energy from a total primary energy in electricity generation of 38.4 quads, or 67%. That’s without the ca. 6% transmission losses – irrelevant for comparisons as they are similar for fossil and renewable electricity.. It’s possible the LLNL are counting the full thermal output of nuclear reactors as primary energy.

          • Richard Foster

            That’s the data I was referring to. I was being generous with 60% waste, building in a factor that some will still be wasted, even with renewables. I wasn’t aware that didn’t include transmission losses though (which is therefore an even better scenario)

            The point still stands that we don’t need to fully replace the FF power generation capacity with renewable capacity – because of the fact we lose less through wasted heat from non-thermal generation (although biomass and biogas plants will still generate waste heat).

          • Bob_Wallace

            You can’t add in 6% transmission losses for renewables when that waste is already happening with fossil fuel generation.

          • Richard Foster

            No, I wasn’t doing so. I was being generous with the amount we waste now/will waste later. I was accounting for transmission losses of approximately the same now as in the future (and of course, we could improve on this)

          • Bob_Wallace

            OK, thought you were adding them on.

            Future losses, especially at the distribution level, should drop as we ‘smarten’ our grid and add more solid state controls and replace transformers. I think most of the 6% is at the distribution level.

        • eveee

          60% might be slightly optimistic.

          “For electricity generation based on steam turbines 65% of all prime energy is wasted as heat.”

        • eveee

          Agreed, tipping point is sooner. NRELs 2010 tech based study is a low end benchmark that clearly states conservatively that 80% renewables can be reached by 2050.
          We will need more and get more.
          Question is, will it be fast enough to counter the faster than anticipated Arctic sea ice and Antarctic land ice loss?

  • Ross

    For consistency they should refer to the Nightmare instead of Low scenario.

    • Ivor O’Connor


  • JamesWimberley

    From the report,it doesn’t look as if the UBS report seriously analyses the upper limit on solar penetration.

    Three stylised facts:
    1. Solar output peaks at noon in midsummer.
    2. Solar output declines either side of noon and is zero at night.
    3. Midwinter peak output is half of summer output.
    From 1 and 2, you have a diurnal load balance problem. OK, assume gwhs of cheap storage to get you through the night.
    But from 3, you have an interseasonal problem too. To cover the load then you need twice as much peak capacity as you need for summer. That’s a lot of summer curtailment, which cuts into the LCOE.
    Wind has a quite different variability, and in most places – but not California – it tends to peak in winter, counterbalancing solar. So an optimum renewables portfolio will be mixed. To reduce the need for expensive storage, it will pay to invest in relatively high-cost despatchables like geothermal and CSP+hot salt.

    Conclusion: 50% solar generation may be technically feasible, but it needs a lot more work to show that it is economically plausible. You can’t just project rapid CAGR and wave away the problems at the upper bound.

    • mike_dyke

      Or you get the southern half of the world to pass their summer surplus to the northern part during the northern winter and vice versa.

      Need some good transmission lines, but that’s all.

      Working as a world, we can work it out!

      • jburt56

        For example the Asian Infrastructure movement.

      • JamesWimberley

        Technically feasible, but surely a long way down the list of options. Note the sad fate of Desertec, the scheme originally backed by several blue-ribbon German firms to supply Europe with vast amounts of cheap and reliable solar power from North Africa. It has more or less been abandoned. The economics do not work. North Africa is investing in renewables but for domestic needs. The existing interconnector across the Straits of Gibraltar, and a possible one from Tunisia to Sicily, are being considered more as adjuncts for load management and backup, like those within Europe.

        The civil strife in Mali points out the real security risks of a transcontinental link. You can’t guard the whole Sahara, and the Touaregs could blow up the line any time they felt aggrieved, which is often.

        • mike_dyke

          Well if UBS are allowed to dream, then so can I.

          • nakedChimp


      • Ivor O’Connor

        So take LA as an example, at roughly 34 north, or 4000 km from the equator. So 8,000 km long HVDC line. With twists and turns probably easily 10,000. At 3.5% loss per 1,000 km about 30% of the energy would be lost. So it is physically doable.

        Now how do we get a HVDC line through all those countries we have been screwing over for the last half century and longer? And at what cost?

        • Bob_Wallace

          Or you put a lot of solar along the southern US border and in Mexico. Tie it into existing transmission. Beefing up the lines as needed. The routes are established.

          • mike_dyke

            Yep, that’d work.

          • Mike Dill

            Already doing that. One of the newer 500MW plants is just outside of Yuma, AZ, and just a few miles from the Mexican border.

        • mike_dyke

          Physically, most of the HVDC cables are already in place and are used by the internal grids of the countries involved, so it’s mainly a matter of connecting up to them over borders. You might be able to reduce the losses by putting storage in the line, so you effectively have 8 x 1,000km links not 1 x 8,000km link.

          Politically, this might be more difficult but just by working together to make the border links physically possible will improve working relationships between the two countries as the railways did years ago.

          Finance? Use the money currently spent on subsidies, production costs etc for the FF we currently burn. Cheap electricity is going to make savings all over the place and affect all people, so what do you spend the money saved on unless you think big?

    • Ivor O’Connor

      With prices continuously dropping we may find it cheaper to convert the excess solar and wind into methane for the winter. Merely as a precaution to ensure we always have electricity.

      • globi

        It may often be cheaper to simply curtail PV-power.

        As opposed to PV in 2050 gasoline in 2015 is expensive energy and so far brakes (which are very frequently used curtailing machines) have never been discussed as deeply as solar-storage options.

        Curtailing PV is also not limiting energy production as much as one might think.
        For instancing curtailing maximum PV-power-output by 30% (of installed nameplate DC-capacity) only leads to an energy loss of 1.2% on a east-west arrangment:

        • Ivor O’Connor

          So you are saying more panels should be installed but at a much steeper angle so summer and winter energy output are the same?

        • JamesWimberley

          Yes. The E-W orientations are crucial to flattening the “fried egg” solar generation curve. But for this to happen you need TOD feed-in or PPA pricing. SFIK nobody offers this anywhere. Sightings would be very welcome.
          This addresses the diurnal problem but not the inter-seasonal one.

          • Ivor O’Connor

            I’m pretty sure I’ve seen the E-W orientation topic before here on CT. Images of panels pointing towards the sunset and panels toward the sunrise but not much in the middle of the day.

            However I took his E-W image and carried it a step further on how it would help with balancing the seasons if pointed much further southward. Past the winter suns azimuth. Would it be cheaper than storage?

          • mike_dyke

            E-W is what I’ve got on my house roof – I get about 80% of the rated value of the arrays if they were facing south.

            As the sun moves across the USA (for example), noon (and hence the best of the sun) is generated at different times e.g. California (PDT) three hours ahead of New York (EDT). If you could have an agreement between the two areas to swap excess power, then spare power generated at noon in California would cover the morning peak of New York and spare power generated at noon in New York would cover the evening peak of California.

            To cover the seasons, go between North and South lattitudes. e.g. USA/Canada and Argentina/Brazil/Chile.

          • globi

            By the way, China is already building single transmission lines with a length of 2600 km and a capacity of 10 GW. link.

            And then there’s also this one in Brazil:

          • mike_dyke

            Thanks for the links – it looks like someone else is thinking along the same lines.

            China is actually better than the USA in that case as it covers 5 time zones (although it only has one time) so can smooth out solar over production a lot easier.

            Russia is the best as it covers the most time zones (10) – Wonder what they’re doing about it?

          • Bob_Wallace

            East or west facing panels will produce about 10% less electricity than south facing panels. The percentage will differ depending on latitude.

            Installing part of your array east and part west would require “10%” more panels to meet your needs but lower storage needs, extending the solar day.

            Considering that there may be a 10% charging loss for batteries it seems to me that E/W is going to win.

          • globi

            The panels produce less energy, but the same roof produces about 40% more energy with E/W in central Europe (because much more roof area can be covered with panels): link.

          • Bob_Wallace

            That’s very interesting. It’s off to Zach as a potential article.

            Now let’s consider sloped roofs. Let’s say a country decided it wanted to use rooftop and not large solar farms. By using three slopes on each roof they could create a massive increase in potential.

            If an E/W slope produces 90% (pick your percentage) as much as a South slope the a country/area can increase its solar potential by 2.8x. A 10 kW south slope plus two 9 kW E/W slopes.

          • Bob_Wallace

            With as little solar as is now installed I think we’re a long ways from needing TOD pricing.

            Some TOD will happen automatically in merchant pricing systems. Someone will do the pencil work and discover that by orienting their farm west-facing they can sell for a higher price and more than make up for the gross generation drop.

            I would expect west-facing PPAs might happen as the duck’s belly drops lower. If facing west causes a 10% decrease in total generation that can be overridden by a 10%+ better selling price. (Remember how a modest amount of installed solar has driven the wholesale cost of electricity very low in Germany on sunny days? I’ll post the graph again.)

            Seasonal, I’m not sure that’s a huge problem. The areas that get less wintertime sunshine tend to get a lot more wind and hydro input. They might simply have a lower percentage of solar capacity than places with year round sunshine. Solar, for those ‘toward the poles’ areas might be treated more like peaker generation, used to help deal with summer AC draws.

          • Hazel

            I’ve been advocating for retail visibility into fine-grained (5-10 minute increments) day-ahead pricing here for some time. (Real time pricing results in too much volatility/instability, but day-ahead forecasts can be quite accurate.)

            That would drive battery adoption as well as solar.

      • JamesWimberley

        As Bob Wallace has pointed out, it’s expensive to keep chemical plant idle much of the time. IMHO the economics depend on an electrolysis scheme with really low capital costs, even if it’s very inefficient – ex hypothesi the electricity is free or nearly so. The hydrogen can be stored, so the plant to convert it into methane and liquid fuels can be 24/7.

        • Ivor O’Connor

          I’m under the impression it is always more cost effective to convert the hydrogen, gotten via electrolysis, to methane for long term storage. And you will always have idle power plants during the summer months as the solar panels excess energy is saved away. Expensive or not. IMHO.

          • Bob_Wallace

            Cost of storage may be the killer.

            If we could economically convert excess solar/wind generation into a liquid fuel then we might be able to store it like we store large amounts of petroleum.

            Hydrogen would seem to be too difficult/expensive to store in large quantities.

    • vensonata

      Yes, you are right. anybody seriously living off grid in the northern latitudes understands this problem with solar. Seasonal balancing is the problem, and it can be addressed by hydrogen storage of excess in in summer for winter use.

    • Ronald Brakels

      Just for the snake of the arguement, lets say solar costs 1 cent a watt to install in Australia. What happens then? Well, we’ll load our roofs up with so much solar that we’d never have to pay for grid electricity during the daytime, whether it is cloudy or clear. This means the wholesale price of electricity will drop to zero during the day and so there would be no feed-in tariffs, so no difference there for many Australians. Our grid would take the solar electricity for free and sell it to people and factories without solar or without enough to meet their needs and make money from that. Electricity prices would be low during the day, so demand would shift to the day to take advantage of that. We would have plenty of excess capacity so winter and cloudy days wouldn’t be a problem and existing pumped storage and any new storage would charge up during the day without problem. We would end up having far more than 50% of our total electricity use from solar.

      Now let’s pretend that the cost of rooftop solar is somewhere between 1 cent and $1.01 a watt. It seems likely that there is a point within that range where we would end up getting more than 50% of our electricity from solar. So provided the cost of solar is low enough, we will get more than half our electricity from it. Or at least here we will. Other places might be weird.

    • Bob_Wallace

      I’d like to see the thinking behind the 50% number. It sounds high to me. But –

      They could have assumed a lot of storage. They may have factored in much higher population density closer to the equator where seasonal differences are slight. And they might have anticipated massive EV charging during daylight hours.

      Those areas further from the equator where there is a large seasonal difference may rely more on wind and hydro then use solar as a summertime peaker to deal with AC demand. AC with water storage might become the norm, meaning that a lot of midday solar generation could end up running (assisting) AC units into the night.

    • ToddFlach

      Hi James, methane can be synthesized using surplus electricity that powers electrolysis of water to produce hydrogen, which is then combined with CO2 using the process invented by Sabatier in the 1910s. The methane would be produced during periods of excess PV and wind production, and stored in the same underground geological formations used today for seasonal storage of natural gas. The process can be made CO2neutral by using a source of CO2 that would otherwise be emitted to the atmosphere, for example from production of ammonia for feritilizer, production of ethanol, production of methane from anarobic digestion of biomass, and many, many more other processes which are essential for our everyday needs. This strategy has been dubbed ‘power-to-gas’, and has been demonstrated on small-scale pilot plants across the globe.
      This can in theory soak up all curtailment and solve the challenge of seasonal energy storage.

      • Bob_Wallace

        Can be. But cost will determine “will be”.

        Lots of interesting things can be done but cost prevents them from happening. What’s the cost of converting electricity to methane and then back into electricity?

        Can it beat, for example, pump-up hydro storage at 5 to 7 cents per kWh?

      • Ivor O’Connor

        I’ve seen Bill Gates say this is the way to go on a Ted Talk I believe. He seems to think it is dirt cheap to go back and forth between methane and hydrogen. Somebody should put actual numbers on this though.

      • Steven F

        “The process can be made CO2 neutral by using a source of CO2 that would otherwise be emitted to the atmosphere, for example from production of ammonia”

        the chemical formula for Ammonia is NH3 There is no carbon in ammonia. When the production process for Ammonia was invented many of the first plants only used only air water and electricity to make ammonia. Methane is used today because it is a very cheap source of hydrogen.

        Ammonia also is not only a fertilizer. It is also a very good fuel and a chemical feadstock. It is easier to store and manufacture than methane or hydrogen. Also it is a lot easier to extract Nitrogen from the air then it is to extract CO2 from the air. Given its wide veriety of uses and it’s proven potential as a fuel it makes more sense to me to make Ammonia instead of Methane.

        • Bob_Wallace

          Can you talk to the relative cost of producing H2, methane and ammonia from electricity? Something along the lines of “slightly more” or “2x more” would be adequate.

          And the cost/problems of storage?

          Any idea what the round trip efficiency might be?

          • Ulenspiegel

            Fraunhofer gives for methane (P2G):

            7 cent/kWh for productiion facility, 5 cent/kWh -> 12 cent/kWh

            this for 6300 FLH of the plant, with only ~1500 FLH you get around 20 cent/ kWh, (for comparison: energy content of 1 liter diesel is 10 kWh, of 1 m^3 methane is 10 kwh) . The crucial aspect is the utilisation of the plant, an issue you have more with PV than with wind.

            The yield for the elctrolysis step is already in the 85-90% range, for the second step in the 80% range, so 70% yield for conversion of electric energy to chemical energy could be expected. The round trip efficinecy of electricity-methane-electricty will be in best acsr only in the 40% range.

            I have no numbers for the costs of electrolysis in comparison to the methan synthesis step.

            I bet with some losses you could produce liquids in the same reactor type with slightly higher losses.

            For me connection of uncorrelated wind production with HVDC lines looks more promising than high volumes of synthetic methane.

          • Bob_Wallace

            With 40% efficiency you’d have to put in 2.5 kWh of electricity in order to get 1 kWh out. If the wholesale price of electricity is 3 cents then the input price for 1 kWh output would be 7.5 cents.

            One might argue that the methane could use free/almost free electricity that would have otherwise be curtailed. But I would guess that wind/solar farm owners would demand some price for their product.

            “7 cent/kWh for productiion facility, 5 cent/kWh -> 12 cent/kWh”

            Now we’re up to 14.5 cents (7c methane plant, 7.5c electricity). No price for long term storage, add some pennies. Add on some more pennies for the CCNG plant to turn the methane back into electricity.

            PuHS efficiency runs 85% or higher. The cost of storage is hard to nail down but it looks to be in the 5 to 7 cent range. A kWh out would cost 8.6 to 10.5 cents with 3 cent input electricity.

          • eveee

            Wikipedia has a nice table. I have been down this road. The table numbers are reasonable. Clearly, round trip efficiency is poor for electricity. Based on markets, heating could be a more beneficial use than electricity, especially for Germany considering seasonal heating.
            Same question. Which is cheaper, and how much storage vs excess solar/ wind.
            Authors like diesendorf argue leaning towards excess capacity. I agree. Since that’s over a decade away, our crystal ball is cloudy. Many new techs can spring up until then.
            Storage is useful and needed, but we probably don’t have the right perspectives on it, IMO.
            We seem to be going about it backwards, with the least expensive options first. Demand management and efficiency are cheaper and superior.
            Here’s my crystal ball. Smart plugs, demand management, and user demand monitoring will converge with utility real time rate broadcasting to lower energy cost. This could be a boon for utilities, but they are past the Kodak moment.
            Storage is in there, too, but utilities have woken up to the PowerWall moment. They recognized and know that $250/kwhr puts storage cheaper than gas peakers. Had PowerWall been available in larger volume a year ago, California could have avoided adding possibly the last gas peakers added to its grid to replace songs.


            FYI, P G and E has dropped their rebates for smart meters. A backward step into a Kodak moment.

          • Bob_Wallace

            Agree. Dispatchable load is going to eat away at any ‘surplus’. But the problem of prolonged low solar/wind will still be with us. At some point (much further down the road) we’ll have to deal with that.

            Will it be cheaper to overbuild, install long term storage, or perhaps pay some very high consumers (pulp mills, aluminum smelters) to take a vacation?

            It’s just an off the cuff thought, but what if we told workers that they would get their vacations but the times would only be known a day or two in advance. But they’d get time and a half or double time pay to compensate for the short notice. And paid plant owners for lost profits, plus a sweetener. Wonder how the numbers would pencil out?

            One can get a feel for how frequent these low input periods are by looking at the orange fossil fuel backup blips on the graph below.

            (Those blips do not take into account dispatchable loads and power sharing across grids.)

          • Bob_Wallace

            Oops, clicked on wrong image.

          • heinbloed


            If it wasn’t for Disqus wanting me to register every time Your postings (and those of many other!) would get many more ‘thumbs up’ greetings.


          • Bob_Wallace

            You’re doing something weird. You seem to have a new email address quite frequently. (I’m not sure if it’s different with each post.)

            I tried to email you about the problem several days ago and got a ‘mail can’t be delivered’ message.

            Both Richard and I have added your email to the Whitelist multiple times. Your posts should go straight through, unless you’re using some sort of “hide me” service?

          • eveee

            We have old storage estimates in the 10% range. Not sure what good they are with the advent of EVs and Power to grid or home, not to mention recent massive PowerWall storage cost implications.
            We have switched from renewables needing storage to storage displacing peakers instead with breathtaking speed.
            It will take time for researchers to digest these latest rapid advancements. They are coming too fast to make good predictions yet. UBS took a whirl at it. I suspect we are far from done yet. EVs are a comin.
            Prospects are for radical change earlier than expected that no one saw coming so soon.
            Sounds like arctic extent ice, too, eh?
            It’s a race.

          • Bob_Wallace

            I expect things will continue to speed up. There is a tremendous amount of money on the table and a lot of people are going to be going for it.

          • Ulenspiegel

            If one kWh of methane from P2G process costs around 12 cent (7 cent capital costs + 5 cent electricity) and you get a 40% efficiency for the re-generation of electricity, on kwh costs around 40 cent.

            The point is that the chemical plant produces high capital costs which make the price of the electricty input less important.

          • Bob_Wallace

            Now, anyone got a handle on ammonia as a deep storage option? Cheaper than hydrogen and methane overall? How much cheaper?

            I’m looking at those orange blips and the longest purple bars. Wondering what technology might be the cheapest for meeting those needs? It’s got to be something fairly efficient, fairly low conversion/reconversion cost, and cheap mass storage. (PuHS and what?)

          • Ulenspiegel

            In the German context methane looks promising because you have already the infrastructure in place.

            A complete different approach, which of course could be combined with methane, ammonia or hydrogen is large scale liquifaction of air.

            As all these processes require large amounts of excess electricity, we have no need for them within the next 20 years. Let’s do some research, but do not push for large scale application.

          • Bob_Wallace

            I agree. It’s much too early to begin implementation. But it’s not too early to wonder. ;o)

          • Ulenspiegel

            We are talking about the following process:

            methane from electricty(storage of methane) – electricty from methane

            The first step costs 12 cent/kWh, in the second step we have an maximum efficincy of about 50% (fuel cell) or 40% with open gas tubine, i.e. the electricity costs 2 times or 2.5 times what a kWh methane costs, i.e. 24-30 cents.

          • Bob_Wallace

            Plus some cost for the gas turbine.

            I would expect a combined cycle plant. Grid managers would see a shortage looming and start the gas plants well before storage was depleted.

          • Ulenspiegel

            CC turbines require more than 3000 FLH to be an economic solution due to their high price and they are not that flexible, to my best of knowledge they are not peakers.

            All studies I have read work in high RE scenarios with open turbines because most gas turnbine would be used for only a few hundred hours per years.

  • eveee

    It’s hard to tell which rate of progress is faster. Battery and clean technologies or investors and researchers changing their minds about how fast and how much alternatives will be implemented. I think minds are changing faster. An energy revolution has started. Teslas moves are crushing the doubters.

    • Ross

      I think the faster progress is with investors and analysts.

      • eveee

        Touche. They don’t want to get caught napping. For once, greed is on our side. 🙂
        Musk sure is a cunning devil, isn’t he? Turn the very system that created the mess into its solution.
        He wins two ways.
        1. Those that like his message and want to be part of it.
        2. Those that don’t believe his message and see $$ and want to be part of it.

  • Will E

    Solar makes a lot of money. Its a business case, good investment, ROI from day one for a long time, stable and secure, and can be done simultaniously everywhere.
    city solar community parks must be installed by law, to make money for schools sports healthcare and senior care. homemade health and wealth.

    • Marion Meads

      What this article did not discuss are the rooftop solar installed by households and big businesses that own their pieces of land. The article primarily based on old business model of behemoth solar plant producing energy that will be distributed like what utilities are doing now.

      In fact, for the utilities, customer installed solar and storage will eat a lot of their money. Big industries like GM, Tesla’s Gigafactory, WalMart’s roof tops have deprived the utilities what would have been lucrative revenues.

      So the utilities will have to find other customers such as the burgeoning electrification of transport.

      • Ivor O’Connor

        Or simply charge slightly less for grid hookup than a Tesla Powerwall equivalent.

        • Mike Dill

          Good luck with that.

        • eveee

          I don’t think they can compete. Utilities need increasing demand to keep the load basing PUC system going economically. Higher demand, more capital spending PUC approvals, more guaranteed rate of return.
          When the music stops, they have stranded assets, decreased profits.. Utility death spiral.

          • Larry

            The sooner this happens for the Utility dinosaurs, the better

          • Ivor O’Connor

            I don’t see the music stopping at night for decades. Especially in cities.

          • eveee

            I do. PowerWall. And a surplus of gas turbines. Stranded assets in peak generators , not just base load. The survivors switch to services and grid.nlike EON and RWE.

  • heinbloed
    • Marion Meads

      When you dream, you should dream big. 100% of electricity can be generated by solar by 2025. Just stop all kinds of subsidies, grants, and tax breaks to fossil fuels and divert them to making gigafactories of solar and give away solar panels for free instead. The governments will not spend extra money and everyone will get free electricity. Because of greed of people in power, this very logical scenario won’t happen and will remain a dream.

      • nakedChimp

        I think it’s not just greed but survival instinct for their source of power and income. 😉

      • Ross

        Governments were willing to commit to “whatever it takes” to avert another Great Depression even though that would be minor compared to the Nightmare Global Warming & Climate Change scenario.

      • Brett

        Nah, save the other 50% for wind, don’t wanna leave those turbines out in the cold now.

        • Bob_Wallace

          Perhaps 40% solar, 40% wind, 20% ‘everything else’ – hydro, geothermal, tidal, biomass/gas.

          A mix of inputs will lower the amount of storage needed.

          Higher percentage of solar in sunny places. Higher percentage of wind and hydro in less sunny places.

          • Ross

            Seems like a fair first cut at what the percentages should be. Actual experience will decide the final percentages, we may or may not be surprised at how it turns out. I hope to be around for another 40+ years to see if we do enough.

          • Richard Foster

            That looks to be approximately what I expect as well. The question is how fast….

          • Bob_Wallace

            I think faster than almost anyone is predicting.

            Renewable prices will continue to decrease. Concern over climate change will continue to increase.

            Some places are going to start a serious discussion over the health damages caused by fossil fuel use. Another driver.

            Renewable industries will grow in size to the point at which they have as much and then more political power than fossil fuels.

            IMHO it will be a renewable energy avalanche that sweeps fossil fuels away.

          • Richard Foster

            That’s what I hope for – and believe would genuinely happen. Then I see what the US Republicans have put up to be the next US President, and I’m then not so sure.

            Add in the fact that the Tories here are ending new onshore wind subsidies, people are still dragging feet in the build-up to Paris (although the difference now compared to 5 years ago is still incredibly stark in international politics – China talking about limits, US putting forward real targets etc), and it sows further doubt.

            The defensive rhetoric of FF companies increasing and shifted rapidly though is probably a good sign, such that they’re finally seeing that the writing is indeed on the wall for them.

            The growth of wind and solar PV have been the bright spots. And given how they’ve grown despite the heavy opposition from vested interests. That’s the only reason I think there’s a slight chance that as a planet we’re going to get out of this one. If Solar PV hits about 7-10% global share by 2020 and is still growing, we’ll be alright (if wind is also growing), because we’ll hit 25% of each by 2035 at the latest then, which along with your 20-25% hydro, will see us there.

            I guess the question then will be if the next generation of politicians are braver than the current lot and will take more positive action. Chances are good I’d have thought, because globally my generation and the younger one are far more clued up and aware of the issues (and actively worried) than the dinosaurs who keep insisting on burning their relatives….

            Wonder what the average age of Heartland donors and contributors is – bet it’s well over 60….

          • Bob_Wallace

            I expect some political “noise”. Some governments will be pushing at some times and pulling back at other times.

            But as prices continue to fall governments should play a lessening role, market forces will take over. In fact, market forces are taking over in some places. For example, windy US states with Republican governors who are lobbying Congress for more support for wind and the emergence of the Green Tea Party that is advocating for solar in the SE.

            And, as you point out, the old farts who deny climate change and oppose renewables will die off year after year. Their places will be taken by younger voters who have grown up learning about climate change and are much more likely to support renewables.

            When we start producing some data that shows wind and solar lowering our electricity bills then I think we’ll see a big jump in support. I think that data is starting to appear. We’ve seen a little bit about wind lowering price increases in some states. A few more years of installation should produce some solid price signals.

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