There’s a degree to which, from my perspective, watching for new developments in power storage feels a bit like watching for new developments in fusion power. There’s a promise, both explicit and implicit, that if we just wait a little longer, we’ll innovate our way out of the environmental crisis.
To start with, I want to address that last bit – even if we dealt with climate change, there would still be problems like the “insect apocalypse” (more on that in the coming days), “forever chemicals”, wasteful water use, and so on. Climate change is the most urgent environmental issue, but it’s not the only one poised to end human life as we know it. Multiple systems are in the middle of collapsing, and all of that spells Bad News. That’s why we need a holistic approach to dealing with how humanity interacts with this planet, so that we take care of the world that we hold in trust for those who come after us.
The most common response I see to the intermittency of wind and solar power is the use of various technologies for grid-level storage. I divide these into four basic categories: kinetic energy, potential energy, fuel, and batteries. Obviously fuel and batteries are both forms of chemical energy storage, but they’re used differently, so it feels right to separate them. Given my lack of expertise in this field, there’s a very good chance that my classification is bad, but I think it works well enough for this article.
Power storage using potential energy comes in a few different forms. One of the most everyday examples is winding up timepieces that run using springs or weights. I’m reasonably certain that placing giant watch springs all over the world would not help much, but all potential energy storage relies on the same basic principle – use power to apply force to something from which it can be released, to set it up for later power generation. The most common method at the grid level is probably pump storage. This generally uses either water or air. In the case of water, it’s pumped uphill to a reservoir of some sort, so that it can be released at need through a hydropower generator. For air, it’s similar, except the air is stored in massive tanks at high pressure.
The other method I’ve seen is to literally to lift heavy objects, so that gravity can be used to generate power at need. My favorite version involves putting train tracks on a slope, and having an electric engine move a heavy train car uphill, so that it can roll back downhill and run a generator.
Kinetic energy storage involves making a large object move, and then using that motion and momentum to generate power. The obvious downside is that for this to be useful, it needs to have very large objects, and they need to be moving very fast, without changing location. Pretty much any time energy is stored this way, it’s using what’s called a “flywheel“. There have been efforts to set up grid-level flywheel power storage, but it seems to be a technology with very, very narrow margins for error. If the flywheel is unbalanced by even a tiny bit, the high rotational speed and high mass of the wheel will cause a wobble that could be catastrophic. Think an unbalanced top-loading washing machine in a spin cycle, but it weighs thousands of pounds. If that starts to wobble, you’re in trouble.
The most straightforward use of fuel for power storage is probably hydrogen. Use electricity to split water molecules, producing hydrogen, which can be used either in fuel cells, or for combustion. The downside is that it’s a volatile gas, which can cause problems for safe transportation and storage.
And then we have batteries.
Basically batteries store energy in the chemicals used to build them, in such a way that the energy is released as electricity when a circuit is connected.
There are a lot of different chemical combinations that will get this result, some of which can be recharged, and some of which cannot. When it comes to grid-level power storage, rechargeable batteries are all that really matter. There are also two basic approaches to storying power in batteries. I’ve seen interesting proposals for a distributed model using car batteries, combined with a “smart” grid, to allow power to be directed to where it’s needed, based partly on where it’s not. An electric car connected to the grid, for example, could be partly drained (with the owner’s permission) during a period of peak demand, and then re-filled when demand is lower and/or supply higher. Divided between the tens of millions of batteries you’d get from switching to electric cars, and there’s far less need for dedicated grid storage batteries.
Of course, the practicality of such a system may fall off if we shift more towards mass transit (which we should), so there’s still the question of big grid batteries. There’s a lot of worry that the materials for battery production – lithium in particular – could end up replacing oil as the biggest focus of war and exploitation. We’ve seen the beginning of that already.
That, combined with the hope for an easier transition through cheaper materials, has had scientists around the world trying to find alternative battery builds. If you follow this research a little, you’ll see headlines promising that a newly developed battery tech will revolutionize the power grid and make renewable energy the obvious choice. I think the first one that really caught my attention was the “gravel battery” a few years ago:
The only economically viable way of storing large amounts of energy is through pumped hydro – where excess electricity is used to pump water up a hill. The water is held back by a dam until the energy is needed, when it is released down the hill, turning turbines and generating electricity on the way.
Isentopic claims its gravel-based battery would be able to store equivalent amounts of energy but use less space and be cheaper to set up. Its system consists of two silos filled with a pulverised rock such as gravel. Electricity would be used to heat and pressurise argon gas that is then fed into one of the silos. By the time the gas leaves the chamber, it has cooled to ambient temperature but the gravel itself is heated to 500C.
After leaving the silo, the argon is then fed into the second silo, where it expands back to normal atmospheric pressure. This process acts like a giant refrigerator, causing the gas (and rock) temperature inside the second chamber to drop to -160C. The electrical energy generated originally by the wind turbines originally is stored as a temperature difference between the two rock-filled silos. To release the energy, the cycle is reversed, and as the energy passes from hot to cold it powers a generator that makes electricity.
Isentropic claims a round-trip energy efficiency of up to 80% and, because gravel is cheap, the cost of a system per kilowatt-hour of storage would be between $10 and $55.
This is a thermal battery, rather than a “chemical” one, but it sure seemed like a wonderful thing back when I heard about it in 2010. It promised effective large-scale power storage at a low price, and as far as I can tell, it hasn’t really gone anywhere since. The company discussed in that Guardian article is no longer in business.
Research continues, though, and now there’s another one, this time promising to use “iron flow” technology:
Flow batteries, however, look nothing like the battery inside smartphones or electric cars. That’s because the electrolyte needs to be physically moved using pumps as the battery charges or discharges. That makes these batteries large, with ESS’s main product sold inside a shipping container.
What they take up in space, they can make up in cost. Lithium-ion batteries for grid-scale storage can cost as much as $350 per kilowatt-hour. But ESS says its battery could cost $200 per kWh or less by 2025.
Crucially, adding storage capacity to cover longer interruptions at a solar or wind plant may not require purchasing an entirely new battery. Flow batteries require only extra electrolyte, which in ESS’s case can cost as little as $20 per kilowatt hour.
And so we have yet another “game-changing” power storage technology, and it feels like in another 10 years I’ll be wondering whatever happened to that.
This used to confuse and frustrate me, back before I started studying politics and economics. Back then, even Republicans had been admitting the need for climate action, and I kept being told that the only real obstacle to renewable energy was the “inconsistency”, and the lack of affordable power storage.
I’m still frustrated, but I’m less confused. I honestly don’t know how viable any of these technologies are. Various people who are better than me at math have made various claims about this stuff, and I don’t have ability to parse those directly. The one thing that everyone who cares about climate change seems to agree on is that we already have the technology to make the changes needed, what we lack is the political will. For some, that’s about renewable energy, for some it’s about nuclear, and for most, I think, it’s about a combination of the two.
Are these iron-flow batteries enough to make the transition away from fossil fuels easy? No. Because lack of storage technology has never been the primary obstacle to that transition. Would they be useful if we actually went all-in on dealing with climate change? I don’t know, but trying does seem to be the best way to find out. The same is true of the gravel/thermal system, and the distributed car-based system. It’s even an area in which some level of competition could yield good results for humanity, but despite what neoliberals might tell you, that competition is being blocked by capitalists, not by “the government”.
I guess the point of this post is this: We have tools to deal with climate change that we are currently not using. We are also constantly developing new tools that also don’t get used. We need to organize, to train, and to take power out of the hands of oligarchs and their ilk. Only then will we be able to use the collective might of humanity for the benefit and survival of humanity.
All we have is us, but if we work together, that should be plenty.
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Giant watch weights might come in handy, though – click –, – click –>*
I am reading about these technological innovations as a way to keep hold of my sanity.
The problem is not a lack of viable solutions, it never was. We had at least some of the solutions for switching to a mix of renewable and nuclear energy fifty years ago. If we started implementing them then, we would be green now. However fossil fuels are the cocaine that makes our civilization run – whilst renewable energy is the potatoes. And it is hard to persuade an addict to quit their drug in favor of a bland meal.
So the problem is the lack of political will to stop subsidizing fossil fuels and leaving libertarian-style free-market capitalism for everything else getting more and more rabid.
Mind you, the so-called socialist countries in the Cold War era had a terrible record with regard to environmental protection too, as does China ruled by the communist party.
Protecting the environment just does not bring you money, or power, or both. Ad regardless of the actual political regime, those who wish to wield power over others always end on top and abuse said power.
Re: the links, I’ve always wanted to set up a generator in a city where people could “charge it” by pulling on ropes tied to various weights, and it could power, I dunno, phone chargers or a cooling station or something.
On the USSR, China, et al, I feel like the “state capitalism” distinction serves fairly well. The same worker/employer power dynamic still exists/existed in those situations, it was just the state exploiting workers rather than capitalists.
In China it seems to be a bit of both. I don’t know that I can say it’s worse than our system, but it’s also not enough to save us.
Hence the focus on collective power organized from the bottom up.
This reminds me of a discussion with some “alternative energy” boffins I knew back in the ’70s, about energy storage via compressed air.
The problem then and now goes back to Boyle’s Law. When you compress air, you generate a lot of waste heat; releasing that air creates a very localized cold spot. Find ways to functionally use that heat and that coolth, and you have an economically practical system; if you don’t, you won’t.
Possibly certain types of food processing could work with heating at one end and cooling at the other – but managers of such systems do NOT like merely semi-predictable energy availability. It does not seem as if the state of the art has advanced much since the Carter years.
Chicken-and-egg problem; it’s not cost effective to build storage until there is a good excess of renewable energy, and it’s not worth building excess intermittent renewable energy (solar/wind in this case) until there is a way to store it.
It’s not so much that they don’t work or don’t scale, it’s that they’re not as cost-effective as burning gas or coal. Especially when gas and coal are subsidised and don’t need to account for externalities.
Here’s one you did not mention: Has Henrik Stiesdal nailed yet another market disruptor? — hot rock grid storage.
(Video, 13:31s)
Anything that requires sacrifice and personal responsibility is deemed “unnecessary and unworkable”. People pretend to care, but they want a magic bullet. Or a better analogy, they want to have enough for retirement, so they expect to win the lotery.
@John Morales It looks like that one’s very similar to the gravel thing. I’m glad to see things like that are still being used.
And yeah – I think the biggest problem is that profit comes before all. The concept of an investment for the common good is alien to neoliberals.
Why do you say that? You seem to be manifestly wrong.
Regarding some of the things that you’ve said: See the following blogs with easy to follow calculations on the substantial limitations of pumped hydro storage (insufficient land) and many kinds of chemical battery storage (insufficient lithium, nickel, lead). The author is pretty good in these two posts on these topics to make it accessible.
https://dothemath.ucsd.edu/2011/11/pump-up-the-storage/
https://dothemath.ucsd.edu/2011/08/nation-sized-battery/
It’s also foreign to literally 99% of the anti-nuclear advocates that I talk. Almost without exception, anti-nuclear activists will talk about cost, and almost without exception, they will blindly cling to LCOE and discount rates as the proper way of comparing costs. However, LCOE, and discounting in particular, is a convenient tool for the private investor with a short-term time horizon. LCOE and discounting is a wholly inappropriate tool for “investing” for the common good. For example, LCOE and discounting easily leads to situations where solution A (e.g. solar and wind) has a cheaper LCOE compared to solution B (e.g. nuclear), but also higher upfront costs and higher yearly upkeep costs. For some pretty graphs and more explanation, see here:
https://thoughtscapism.com/2019/11/05/decarbonisation-at-a-discount-lets-not-sell-future-generations-short/
I explain this, and give numbers and examples and links, and I have never seen an anti-nuclear person that I’m talking to change their mind on this. It’s beyond frustrating. They pick and choose what facts to believe depending on what is convenient to support their prejudices in the moment, and they’re change back and forth depending on what’s convenient, sometimes multiple times in a single conversation.
Why is it that 99% of all cost comparisons used by renewable advocates are done with a wholly inappropriate financial methodology – a financial methodology that favors short-term thinking and private personal financial gain instead of the public good? And gods damn it, why can I never get someone who cites LCOE to admit that they were wrong to cite LCOE?
PS:
99% of LCOE numbers are also wholly inappropriate because they only look at small portions of the total costs and never whole cost comparisons. They look at the costs of solar cells and wind turbines in isolation, without any equipment to transform the intermittent electricity into reliable dispatchable electricity, but all of those other costs are easily 90% of the total system costs, and they compare it to nuclear, where the cost of the nuclear power plant (including fuel, decomissioning, etc.), is a large majority of total system costs. This is why I say that right now, solar cells and wind turbines could be free and plentiful, and it would never be cheap enough, because the problem has always been impossibly hard difficulty of dealing with the intermittency at very high penetrations of solar and wind.
The reason I say that tech isn’t the primary obstacle is that there are numerous things that we can and should be doing, that we’re not, because those with political power don’t think it will benefit them. It’s pretty obvious.
Building efficiency, mass transit, changes to agriculture, preparation for sea level rise, and the list goes on, and on, and on.
The obstacles to dealing with climate change are political not technological.
Well Abe, I agree the problem is political and that we don’t need new technological breakthroughs. I just think you’re not naming the biggest political opposition to all feasible solutions, i.e. the mainstream anti-nuclear environmentalists.
And on that we continue to disagree. I still think you’re discounting where power resides. We agree on the problems with environmentalism in the 20th century (most of them, anyway), and on the white supremacy that has been baked into that movement from the start, but just as you think that fossil fuel interests and the like have guided the “movement” away from nuclear – which I’m sure they have, to some degree – those same interests have also put a huge amount of resources into blocking action more directly through propaganda and government corruption, and that has had a far greater impact than even the worst parts of the environmental movement.
You’re focused on a symptom, not the disease.
I say again, my home state of California had enough nuclear power plants in the planning and building phases circa 1070 when Jerry Brown was first elected governor, that if they finished, California today would have close to 100% nuclear electricity. But then Jerry Brown was elected, and with the help of the newly birthed anti-nuclear Green movement, he killed almost all of those nuclear power plants, so that he and his family could get richer on their massive fossil fuel financial ties and investments. If it wasn’t for the Greens, California would have drastically reduced its greenhouse gas emissions, and it would have done so for reasons other than climate change.
Nuclear is the best energy source by far, and we should be switching to it as fast as we can for reasons other than climate change. Climate change is just another (very) compelling reason to switch as fast as we can.
Germany is another example. They’ve spent so much time and money on renewables that if they had spent that time and money on building nuclear, they’d basically be done by now and have 100% nuclear electricity, and enough electricity left over for an all-electric car fleet too.
You can look at the recent COP conference, where little to nothing was said about nuclear. The world continues to dither and waste time instead of honestly addressing what needs to be done to fix the problem because a large portion of the world population has been duped into believing ludicrous lies – that renewables can (easily) replace fossil fuels worldwide, and do so cheaply, and that nuclear power is expensive, and that nuclear power is unsafe.
Actions have consequences.
And of course, I need to mention that the German political leader overseeing the decision to phase out nuclear (in a political alliance with the Greens of course), is now receiving money from the Russian national natural gas company Gazprom.
*1970, not 1070.