How do they deal with variability of all these renewables? Where is all that storage going to come from?
Only realistic path is nuclear, but it'll take longer than 2035.
Only realistic path is nuclear, but it'll take longer than 2035.
They claim the lowest cost model for generating 100% renewable involves 5x the capacity being built.
However, they recommend rolling out 12x because that would provide another 500Twh of energy for only a 20% increase in spend (while reducing the amount of battery needed by 50%). A concept they have cheesily named "superpower".
See the table at the bottom of page 4:
https://static1.squarespace.com/static/585c3439be65942f022bb...
Welp, they sure are cheap when made by mostly-coal-based China.
While nuclear is one of the most expensive electricity sources, with surprisingly limited fuel reserves given the energy density, it's incredibly safe (despite the reputation) and I think there is inherent value in a diverse supply that can make up for the sticker price.
> How could they deal with variability of all these renewables?
I’m guessing a mix of pumped hydro, purchased hydro and nuclear, home storage, robust grid, increased energy efficiency, smarter usage periods for heavy users such as industry or EV charging, etc. And then there is emerging technologies such as on-site carbon capturing of natural gas power plants, liquid metal/molten salt batteries capable of robust large scale grid storage, etc.
Solutions do exist, and no one of them will solve it for all, but together they will.
RethinkX addresses variability in their full energy-related report (see part 2): https://static1.squarespace.com/static/585c3439be65942f022bb...
A large variety of places, but not by replacing 100% of electricity and only electricity in one region at a time.
You replace 30% of electricity. That's easy.
Then you replace a bunch of dispatchable non electric loads and use the times the new generation can produce electricity to replace another 20.
Then you add a bunch of 4 hour storage and dirt cheap thermal storage. You get another 20.
Then if there's finally a breeder reactor it can join the party, otherwise you round out the rest with storage as the price plummets. Burner reactors are irrelevant.
So Germany had to help out France with energy mostly this year.
All the other years France was a net exporter of electricity. But no worries, Germany have plenty of coal to backup those 500 billions renewable.
They actually rule that out in their model. It should make things slightly cheaper and easier if the EU nations all do this and trade energy, but it's not required.
They exclude a few other notable things:
> Our limit scenario makes a number of severely constraining assumptions for the purpose of emphasizing what is possible for 100% SWB systems. The bar for clean energy will not be nearly so high in most locations.
Assumption 2: no conventional operating reserve
Assumption 3: no other renewables
Assumption 4: no distributed generation or storage
Assumption 5: no impacts from electric vehicle energy storage
Assumption 6: no demand response, load shifting, energy arbitrage, or peak shaving
Assumption 7: no technology breakthroughs
Assumption 8: no subsidies, carbon taxes, or other financial innovations
These are all good things, they're not predicting or recommending against them, they're just saying they've assumed they don't exist when running the numbers to prove it would work everywhere.
storage is mature, scaling will be the main obstacle
nuclear is nascent and non-renewable
I bet some of this would sort itself out if they had sufficient renewables, and that the rest would be an easier incremental problem if they made the switch.
An to answer your question, let me quote the first sentence of the article:
Germany can shift its entire electricity system onto solar, wind and batteries by 2030 for less than 1% of its GDP.I imagine something like this as well https://en.wikipedia.org/wiki/Tesla_Megapack
(but my understanding is that there are many other battery technologies in development that work too, e.g. older chemistries and/or mechanical/gravity/heat batteries)
Won't happen all geographically advantageous places are already taken.
Second option (and also a boring one) is distributed home storage using traditional led-acid or lithium-ion batteries. This is already rolled out and can be increased to scale pretty easily.
A more exciting answer is liquid metal (or molten salt) batteries that works as large scale grid storage by heating the batteries elements (Calcium and Antimony) to very high temperature that keeps them separated while charged slowly mixing into a new liquid alloy as it discharges. You can read more about the technology here https://ambri.com/technology/ However I think before 2035 this will at best be a distant third from the two (boring) storage options above.
I think it is OK to be loose on the technicalities in this instance, we all know what was meant.
Batteries are fine for shifting the "when", just like power lines are fine for shifting the "where".
What nuclear energy is bad at is as a backup for renewable energy when there is no wind. Because nuclear costs the same whether you use it or not, so you pay for an energy source you don't use most of the time so that you can use wind instead. If you use nuclear, scrap wind.
If we want to unscrew ourselves of the ticking time bomb we set, we need all the "clean" energy we can get, and then some. Nuclear is potentially an existential requirement to the mix.
Page 4 of their linked policy primer has two options: https://www.rethinkx.com/s/Germany-SWB-Primer.pdf
3340 GWh or 6221 GWh storage.
> Where is all that storage going to come from?
Why do you think that's a useful question? Policy proposals like this are at the level of encouraging people to make fast-tracks for investments and passing planning permission for the factories to build the batteries and the mines to get their feedstocks; governments aren't generally even in the business of directly building the power stations themselves.
> Only realistic path is nuclear, but it'll take longer than 2035.
Not enough fissile fuel[0] for everyone to do that at western usage levels. And if you're talking that long, you can reasonably build out a global power grid, switching people from mining coal to mining metals, and the cost of making a grid of that scale is about the same (at current metal prices) as we currently spend per year on fossil fuels, give or take a factor of two.
[0] or at least, accessible fissile fuel; if you want to filter the oceans you get all the lithium you could want (and more other goodies like phosphate) as well as the uranium.