Solar and wind alone won't work without support by gas or other non-renewable sources. Try to find a single scientific study that gives a detailed overview of how the German energy mix is supposed to work and that explains how supply will be matched to demand 24/7 all year round. None exists. The whole "Energiewende" is built on the hope that either our neighbors will produce the necessary base capacity to stabilize our energy grid, or that a miracle storage technology will somehow be invented in the next 10 years.
I can recommend "Sustainable Energy: Without The Hot Air" [1] by a Cambridge professor, it goes into great detail about the problems of matching electricity demand to supply day- & year-round.
This book has come up on Hacker News before, and I've read it, and it has a crucial flaw, well, two actually:
- It underestimates the efficiency of solar panels by quite a bit, supposing that 10% would be a lofty goal (and arguing on this basis that solar farms are not economically viable). In fact, panels on the market are approaching 20% [1], and 25% seems well within reach.
- It uses the United Kingdom, one of the dimmest countries in the world [2] and one of the most densely populated, as an index for the viability of solar power in any country. In fact, the UK is probably the worst-case geography+population for solar power, and almost every other country would have a better time of it. In this context, it is worth considering that nuclear power may be particularly appropriate for Europe specifically, since it is peaceful, densely populated, mostly north of the 45th parallel, and cloudy, but solar is probably more practical elsewhere.
The real problem with cost estimates for solar and wind power is that they do not necessarily adjust well for the rate of construction. They may be reasonably accurate assuming a constant rate of construction, but a truly worthwhile implementation of solar and wind power would require a much higher rate of construction than is currently being implemented. I rarely see much of the methodology of these studies, but what I have seen basically involves taking the current price of solar and battery installations, applying a few fudge factors, and scaling up linearly. That may not be realistic.
Meanwhile, the cost estimates for nuclear power are based on data from the construction of large facilities, and therefore necessarily incorporate a much more realistic high rate of investment. Nuclear plants are big.
The book doesn't actually use british solar numbers for the rest of the world, it even suggests shipping in solar energy derived fuels from other countries to the UK and that even including the extra conversion and shipping/transmission costs would be competitive with nuclear built in the UK, which implies its a no-brainer for those source nations to use it for their own power.
Where it feels a little parochial, is its focus on the UK as if the GDP or population of the UK matters in the context of a global issue like sustainable energy.
It simply doesn't and he has enough facts and figures available even at that time to put that together, but probably fell into the classic british position of assuming they are more important than they really are in a global context.
Anyone outside the UK must read it in the same way people in the UK would read a small island dweller writing "Yes this might work for most of the UK but the Isle of Man would need to import power, which is simply unthinkable, even though it already does, so maybe we should build nuclear there instead to maintain the islands sovereignty".
Or maybe we can discount the needs of half a percent of the population if they run counter to the needs of the other 99.5% and focus on the big picture?
In the end we didn't need to as the wind power, heat pumps, EVs and carbon fees required for the UK overlapped heavily with other nations but this was a clear blindspot which I think you are charitably interpreting as a silly mistake when really it's more akin to arrogance.
I believe it also assumes significant input from biomass, which has a very large effect on the amount of land area needed because of the extremely low power/area of biomass.
I read the book before the numbers it cites were decades out of date. And even then, it made a pretty good case for renewables in the parts of the globe where most people live.
Once you update it with current figures I'm assuming it can only make a stronger case. So are you just using the old figures and pretending those haven't changed?
That's like trying to model the next iPhones specs from first principles with specs from the last century.
Well it won't have a very big HDD because all that spinning rust will really drain the AA batteries.
edit to add, but his basic strategy is sound:
> The principal problem is that carbon pollution is not priced correctly.
And there is no confidence that it’s going to be priced correctly in the
future. When I say “correctly,” I mean that the price of emitting carbon
dioxide should be big enough such that every running coal power station
has carbon capture technology fitted to it.
> Solving climate change is a complex topic, but in a single crude brush-
stroke, here is the solution: the price of carbon dioxide must be such that
people stop burning coal without capture
The UK basically did this. Note that it was found by the market that replacing the coal plants entirely was cheaper than adding carbon capture to them.
edit 2:
> The most promising of these options, in terms of scale, is switching on
and off the power demand of electric-vehicle charging. 30 million cars,
with 40 kWh of associated batteries each (some of which might be ex-
changeable batteries sitting in filling stations) adds up to 1200 GWh. If
freight delivery were electrified too then the total storage capacity would
be bigger still.
> There is thus a beautiful match between wind power and electric vehicles.
If we ramp up electric vehicles at the same time as ramping up wind
power, roughly 3000 new vehicles for every 3 MW wind turbine, and if we
ensure that the charging systems for the vehicles are smart, this synergy
would go a long way to solving the problem of wind fluctuations.
The UK also did this.
I'm baffled at the books continued popularly with renewable "debunkers". The book clearly described the problems and solutions. The main skepticism was aimed at politicians being able to overcome the political power of fossil fuel lobbiest and do something sensible.
The only explanation is a willful disregard for the new knowledge we've acquired in the intervening time period, much of which the author guesses correctly but we now know for a fact.
There's an E (for economics) plan outlined as a proposed solution, that assumes we'll deploy a lot of the cheapest energy source, whatever that is. It then also assumes (!) that onshore wind will cost the same as Nuclear and offshore wind will cost more. Put those two assunptions together and you get a plan with lots of nuclear.
Note, he's not actually predicting this outcome, though it does seem to be his personal preference at the time. He mentions that cheaper solar-to-fuel might be an alternative, as what really mattered was which was cheapest, which he assumed, incorrectly, would be nuclear.
Actual reality looks a lot closer to his G plan, for 'greenpeace' named sarcastically because they just love wind power, because as it turned out wind was cheaper than basically everything else (until solar caught up in most of the world). Maybe Greenpeace got lucky, maybe they were just better informed.
So if he was to rewrite that same plan with today's figures, the Economist and Green party plans would probably agree. Amusingly ironic and a testament to his methods even if his clearly stated assumptions no longer hold true.
I'm mostly referring to the section on storage, which is still largely true today. Germany does not have enough mountain areas to build significant hydro storage, and no other storage technology currently comes close to that in terms of efficiency and scale. We could of course produce hydrogen and burn that again but there the round-trip efficiency is only around 20 % in the best case I think (up to 50 % if we could use the waste heat as well), compared to around 80 % for hydro. Hence we would need to over-provision wind & solar energy production by 400 % to use this form of storage, which is highly unlikely as we will have trouble fulfilling our current ambitious goals for wind and solar, which already require a 500-1000 % increase in construction rates over the next decades.
Batteries would be another candidate but again the required amount of energy and the power slew rate are enormous, so storage facilities would be extremely costly and would compete with electric car battery production. I don't have much faith in the idea of storing energy in electric vehicle batteries as most of these cars will be on the road when the energy is needed (7-9 am) and will be mostly plugged in to charge when renewable production is low (during the night). Also I'm not sure if the electricity grid would even allow such a conversion as it's not designed for many small producers arranged in a mesh.
The section on storage that literally starts by pointing out that a renewable only or nuclear only plan would both require storage?
And then lays out multiple solutions, including 20Kwh of EV battery storage for every person which must have been basically science fiction at the time of writing but now sounds entirely boring and inevitable for reasons entirely separate from power storage.
Yeah I'd say that holds up pretty well, but I'm still not seeing the problem it apparently poses for today's world of cheap renewables?
We need and want to produce lots of green hydrogen for non-burning purposes. That fits perfectly into the demand response idea he lays out in reasonable detail. So why do you seem to think pumped hydro storage was the only solution he mentioned?
Even with his dated view on PV prices, he raises the possibility of importing hydrogen:
> "Solar photovoltaics were technically feasible for Europe, but I judged
them too expensive. I hope I’m wrong, obviously. It will be wonderful
if the cost of photovoltaic power drops in the same way that the cost of
computer power has dropped over the last forty years."
What a great quote to look back on from a future where his hopes came true.
The evidence that renewables need to be supported by gas and oil is evidential in northern Europe, observed by anyone who pay their own electricity bill. When the wind is weak the market price is determined by gas and oil prices. When the wind is strong the price goes down to basically transit costs. Since the average wind condition is pretty much the same each year, the market cost for electricity has been 100% determined by gas and oil prices for the last decade.
If one also follow energy politics this has also been very clear by the politicians themselves. The green political movement has been advocating the concept of "reserve energy" over nuclear "base load". The strategy is to build out as much wind and solar as possible, while keeping natural gas and oil plant on subsidized plans. When the weather is bad for energy production, those natural gas and oil plant starts up and supply the missing supply.
For oil and gas operators this is a pretty great deal. They get paid twice, once by the government and then a second time by the market. They also only need to spend fuel when the market price is at its highest, reducing fuel costs and improving profits. It is pretty much a win-win situation for the government and power plants operators.
In 2011 ENERTRAG had a constructed a system to use a windpark to produce hydrogen and burn this in a gas/fuelcell plant. But since a change in the EEG Umlage Gesetz made them pay for their own energy produced by wind, it became unprofitable to do so.
If that sounds idiotic to you, that's because the change in the EEG was created to make exactly this impossible.
I can recommend "Sustainable Energy: Without The Hot Air" [1] by a Cambridge professor, it goes into great detail about the problems of matching electricity demand to supply day- & year-round.
1: https://www.withouthotair.com/