I’m German and vaguely pro-green energy in general, but I’ve yet to see one piece by environmentalists that isn’t utterly confused by the difference between energy and power, i.e. how much electricity is generated at any given moment vs. how much is generated in total. You could have a magic fantasy technology that produces a trillion TWh for three dollars. If it were somehow limited to doing so for only 20 seconds each day at noon, it would be utterly useless to fill the electricity needs of a nation.
In theory, you might overbuild wind power to the point where even if it’s running at 1% efficiency on a windless night, that would still be enough. I’m not confident that would work even if we dedicated the entire surface area to wind turbines and lived underground.
These aren't environmentalists, they're interested in tech disruption.
They cover both energy and power:
> Our model takes as inputs each region’s historical hourly electricity demand,
hourly solar PV power generation, and hourly wind power generation for the
2-year period of July 1 2017 through June 30 2019.g
The best number I could find quickly for the current total grid-scale battery storage for Germany is somewhere around 750MWh[1], so they only need to build 13,000 times as much storage as they have as of 2021. That would also only give them a worst-case scenario of around 4 days of battery-only power. That sounds pretty optimistic.
750 MWh is about how many cells the Tesla Brandenburg factory will produce in a single day. And that's not primarily a battery factory, it's a car factory with battery production on the side.
Not sure where the 750MWh/day figure comes from, but if Tesla aims to build 500k cars there annually, that’s only around 42.5GWh total capacity if they’re all top-of-the-line 85kWh models. Or 116MWh daily.
Also, at 750MWh/day, it would likely be the world’s largest battery factory.
250GWh/year isn't quite 750MWh/day, but it's close enough for rhetoric since the OP mentioned 750MWh as the total storage capacity currently installed in Germany.
250GWh/year definitely would be the world's largest battery factory if it was operational today, but by the time Brandenburg ramps up to that it likely won't be.
Because solar and wind are intermittent. UK for example had 11 days in a row in 2021 where wind farms stayed under 20% of capacity during Feb-March [1], the low-season for solar power and high-season in power consumption due to heating.
At the national grid level, you should also want to account for rare, once-every-few-decades scenarios.
Sure, but one of the two options in this report is to halve the battery requirement by building five times as much PV, for an overall cost increase of 20%.
I think the report suggests building 5x capacity of the current electricity consumption, not the final consumption when heating and transportation have also been converted over from fossil fuels.
The main page talks about both, starting with the two options I stated for just electricity after 10 years, and making everything else also renewable after 15.
(On the one hand, if you can build that many batteries, fully electric transport is fairly easy; on the other, I don't think there's a plan to ban fossil fuelled cars soon enough to actually hit fully electric transport 15 years from now, but that's probably an unimportant quibble on this scale of change).
This particular proposal is based on the idea that if renewables are cheap and getting cheaper (which they are) then you should build a lot of them.
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".
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.
Also, China is able to build it at a reasonable price (~$40/MWh). It's not destined to be expensive, the price is just a consequence of excessive safety precautions.
Note that this article says could not will, so I’ll answer a related question of yours that better reflects the article:
> 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.
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.
I feel like variability we can engineer around. What I’m more concerned about as someone generally pro wind/solar is how we’re going to discover and build supply chains for all the extra materials we need for this transition. We need a renaissance in resource exploration, discovery and extraction.
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.
I used to think about this as being a problem, but more and more I'm wondering if this is the wrong way to think about renewable capacity? For comparison, for years ISPs have been saying "what would you do with 1 gbps internet speeds?" And they've been putting of making the change to that because it's difficult. I think sometimes the problems that we expect to happen are a lot harder to be certain of when we're entirely speculating.
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.
Well-known? French nuclear reactors are doing load following every day.
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.
Nuclear should be heavily subsidized regardless. Whenever they aren't needed for immediate demand, these power plants can be put to use for so many other tasks: desalination of water, energy storage in terms of hydroelectric pumping, direct carbon capture. Chemical fuel creation (hydrogen, ammonia, methanol, methane, etc).
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.
Synthesize and bottle carbon-neutral fuels like hydrogen or methanol with surplus off-peak nuclear power. Use fuels for peak on-demand electric, transport, etc.; methanol burns in standard internal combustion engines. Solves both the variable output and battery problem. Cost isn't too pleasant, but it scales and all the tech for this cycle exists now.
Pumped hydro is the obvious answer here, and today accounts for by far the majority of stored renewable electricity. There are geographies in Germany (natural and artificial) that can easily accommodate a lot more pumped hydro.
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.
(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)
But with the other logic, oil is not an energy source either, it is rather an energy storage that just so happened to store energy created by the sun millions of years ago.
I think it is OK to be loose on the technicalities in this instance, we all know what was meant.
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.
Sadly I don't think we are there yet. Some electrical generation is cheaper with renewables. But that only helps with electricity. What about aviation, or construction? We've waited for 50 years for someone else to solve this at no cost to us. We'll wait another 5000 and all drown in floods at this rate.
Well, aviation, sure, we'd either have to make new hydrogen fuelled jet engines, or industrialise Sabatier process and methane fuelled jets, or industrialise Sabatier process and polymerisation of methane into longer chains for direct substitution with existing jet fuel, so that's certainly a thing to doubt.
But construction? Nah, we use concrete because it's cheap, but PV electricity is so much cheaper than other sources it's got a obvious path for widespread use of structural aluminium (and I've seen a demo of electrolytic iron reduction, so also for structural steel), and filling in the gaps between the structural frame has so many existing options it isn't worth listing them all even if I knew them and their various situational pros/cons.
Annnnnd of course they wrote "energy" in the title but they only mentions electricity, as if those where not vastly different (if related) problems to tackle.
They explicitly talk about both, see the second 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. And the country’s entire energy system can go 100% clean energy by 2035 for less than what it spends on fossil fuels.
"Not only will energy be an order of magnitude cheaper than today at zero marginal costs for much of the year; this in turn will create a new possibility space for business model innovation and value creation catalyzing clean prosperity within planetary boundaries."
This seems a bit too ebullient and I almost stopped reading.
But the idea that a transition to SWB can be executed for similar cost to current fossil fuel subsidies seems reasonable.
It doesn't seem to address the big issues (where do we get the people that will install things? how do we make sure one property owner or one frog can't cancel giant programs? how do we increase bureaucratic efficiency in permits?) and feels vague and clickbait-y.
"You can do everything if you believe in yourself", isn't that useful.
They won't use batteries (in the sense of Lithium batteries). They will use other storage technologies that trade off the round-trip efficiency and density of Lithium batteries for much lower cost per unit storage. There are a number of serious contenders, including metal-air and compressed gas, and also direct heat storage.
They are literally proposing using lithium batteries with no big tech breakthroughs at grid scale. If you have other storage sources, like EVs or home batteries, or some magical new tech becomes available, it'll be cheaper, but if you don't they suggest you can do it with lithium-ion and the renewable tech as it stands today, with price reductions coming from scale.
> but if you don't they suggest you can do it with lithium-ion and the renewable tech as it stands today, with price reductions coming from scale.
LiIon batteries are only economical today for the most valuable grid ancillary services, like frequency regulation, where they shine because of their fast response time.
For day to week scale time-shifting of energy, we need something 10x cheaper. If LiIon batteries can achieve that kind of price reduction then great, but the price trend with LiIon has started to level out after getting 10x cheaper over the last 10 years.
> LiIon batteries are only economical today for the most valuable grid ancillary services, like frequency regulation, where they shine because of their fast response time.
Not so; for cost, LiIon+PV can already beat nuclear for the same use cases in most places, what we have not yet done is build the mines and the factories to scale all the way up to this.
Nuclear is the easy bar to pass, and while this report says we can beat all fossil fuels on price this way, I'm willing to doubt that for the sake of arguing against this claim in this instance.
They predict similar for wind and solar, and notably they correctly predicted the price drop of solar 10 years ago till today. Which seemed a crazy thing to suggest 10 years ago.
Storage heaters came with the flat I own back in the UK, which dates back to the late 80s or early 90s. Not even vaguely new. A quick search says the tech dates to 1940s.
Here is a Swedish company making a heat storage system that outputs electricity using a Stirling Engine. They claim 165kWh electrical storage capacity.
> Every non-renewable power source involves a heat engine.
Even some renewable power sources like wind involve a "heat engine" in the sense that they exploit a temperature differential driving a working fluid (AKA wind) to spin a turbine.
curious what projections looked like in 2011 at the onset of energiewiende for a decade + hundreds of billions invested down the line. Probably not that turning off the tap to cheap Russian gas could bring Germany to its knees.
Disappointed but not shocked that the “solution” to the current problem appears to be the same as what led to it, just even more
No, as the first sentence of the article explains this is removing all fossil sources from electricity by 2030, and all fossil fuels by 2035 they are talking about.
> Germany can shift its entire electricity system onto solar, wind and batteries by 2030 for less than 1% of its GDP. And the country’s entire energy system can go 100% clean energy by 2035 for less than what it spends on fossil fuels.
I'm concerned we might have a shortage of unicorns to operate them, though, given how much pixies are eating them.
Sorry, you meant "in the real world" ? 5-10 years is a realistic tentative date for the first few experiments at ITER. Will be nice for physicists, but it won't light a German bulb for a while.
But it seems to me that the main problem with fission today are the time, capital and expertise required to build the plants.
Even if we had a commercializable fusion reactor prototype today, would it be really easier to deploy at scale before we hit 2.5 degrees of global warming?
one thing is a selfsustained reaction in ITER, another is to commercially scale it. Literally a multidecade iteration of various designs. I cant immagine political and public support to build the firsts inneficient fusion powers at a price tag several times the ones for fission power stations (~15B$)
No, it has been _50_ years away for 50 years. Which leaves room for a joke. "Fusion in 5 years" is either Elon Musk-level of estimating, or Elon Musk-level of trolling.
I'm sure I heard it as "20 years away and always has been" back in the late 90s.
(To me, "5 years away and always has been" feels more like the Apple Glass than Musk: one is endless headlines not actually backed up by anything concrete, the other is just persistently overoptimistic about all timescales by a factor of about 3).
As if more over capacity will make the battery problem smaller.
It will cost enormous, the plan compares to the current enormous unaffordable price levels and then even cost much more.
Also it will depend on Chinese made goods. The needed battery capacity is not ever done before and the production capacity is not available in the market.
This is pure fiction, we need to focus on fixes that keep Europe running this winter and next winter. So that not all industries going to go broke.
We need more gas and oil fast. This will need investments. Lots of investment. Not useless day dreams of ideologues.
We need more reliable and consistent base energy in overabundance fast. Nuclear can do this without creating a climate catastrophe. Even if you need energy dense chemical fuels, nuclear energy can be used to create these without net climate impact.
Hydrocarbon fossil fuels are the addiction that modern society needs to break from. Nuclear is an excellent "methadone" to ease the transition. But society seems to be split between denying there is a problem at all, or insisting we're all ready to go "cold turkey". Neither approach is reasonable to bet the continuance of human civilization on.
> We need more reliable and consistent base energy in overabundance fast.
> Nuclear can do this
It's not reliable, there's no overabundance (or even a way to match pace with renewables), and it's certainly not fast. New mines get delayed even more than new reactors.
In theory, you might overbuild wind power to the point where even if it’s running at 1% efficiency on a windless night, that would still be enough. I’m not confident that would work even if we dedicated the entire surface area to wind turbines and lived underground.