We don't need another few-hours storage technology. Batteries are going to clobber that. What we need is a storage technology with a duration of months. That would be truly complementary to these short term storage technologies.
We don't need another few-hours storage technology. Batteries are going to clobber that. What we need is a storage technology with a duration of months. That would be truly complementary to these short term storage technologies.
We need every approach that's viable. Batteries are part of the solution, and will be in future. But I don't see why we we should assume they're better in every way than this approach
A principle in engineering is that for any market niche, only a few, or even one, technology persists. The others are driven to extinction as they can't compete. It's the equivalent of ecology's "one niche, one species" principle.
There are far more technologies going for the hours scale storage market than will survive. Sure, explore them. But expect most to fail to compete.
We need anything that scales quickly, safely, and cheap. Just getting us through the duck curve would be a tremendous win for energy. https://en.wikipedia.org/wiki/Duck_curve
> What we need is a storage technology with a duration of months
Actually, having expandable, highly re-usable tech like this is much better when the capacities are in terms of hours.
This storage, combined with say 2.5x solar panel installation, could essentially provide power at 1x day and night.
Yes, and we have that. It's called Li-ion batteries.
They are good for about 1000 cycles.
This system can run for decades.
Utility-scale Li-ion batteries are good for an order of magnitude more than that.
"LFP chemistry offers a considerably longer cycle life than other lithium-ion chemistries. Under most conditions, it supports more than 3,000 cycles; under optimal conditions, more than 10,000 cycles."
https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery...
https://iopscience.iop.org/article/10.1149/1945-7111/abae37/...
This is the paper that claims 10,000 cycles under optimal conditions.
But if you read it, they measure Equivalent Full Cycles, and it seems that implies 10000 cycles at partial discharge, not full discharge.
The paper calculates everything at nominal discharge upto 80%. Meaning, the installed capacity has to be 25% more than paper value, leading to increased costs.
Add to that, batteries are complex to manufacture, degrade, lose capacity, etc. You need high level of quality control to actually ensure you are getting good batteries. This means, the cost of QA and expertise increases. They are costly to replace, even at an avg of 3000 cycles (roughly 10 years). Bad cells in one batch accelerate degradation and are difficult to trace out. Batteries operate best at low temperatures, so the numbers may vary based on installed location and climatic conditions.
A turbine and co2 compressor system is dead simple to manufacture, control and maintain. A simple PLC system and some automation can make them run quite well. Manufacturing complexity is low, as there are tried and tested tech. Basically piping, valves, turbines and generators. These things can be reliably run for 30 to 40 years. Meaning, the economics and cost efficiency is wildly different.
With such simplicity, they can be deployed across the world, especially in places like Africa, middle east, etc.
On the whole, batteries are not explicitly superior as such. There are pros and cons on both sides.
3000 is still 3x your number.
In evaluating the importance of this, you need to consider not only the time value of money, but also what one might call the "time value of technology". Does it make sense to make the technology long lived when it's improving so quickly? Or do you just replace it in a decade when things are much cheaper? Was "this PC will last 20 years!" ever a selling point?
When evaluating these technologies, you have to look at not just what they cost now, but how rapidly the cost is improving. Batteries are likely improving more quickly than turbines and heat exchangers.
A few hours are sometimes enough to start generators when renewable energy supply decreases. Obviously, the more capacity the better, but costs will increase linearly with capacity in most cases.
Pumped-storage hydroelectricity - where it is feasible - is the only kind of energy storage close to "months".
You can store energy for months pretty easily as chemical energy. Just get some hydrogen, then join it to something else, maybe carbon, in the right proportion so it's a liquid at room temperature making it nice and easy to both store and transport.
Wait a minute...
Oh: pumped hydro is not a "months" storage technology. The capex per unit of storage capacity is far too high.
The point is that's already a well-served market. These competitors are like alternative semiconductors going up against silicon.
Had heard a lot about flow batteries few years back. I am guessing they are slowly taking off as well, the trial and error that explains their feasibility , need and ability to pay for themselves in a market like ERCOT is the key.
This is one place where I think by 2030 a clear no of options will be established.
I don't understand. Why is a duration of months preferable? What is the benefit above storing energy beyond say peak-to-peak? I suppose you can flatten out seasonal variation, but that's not nearly as big of a problem.
To see the importance, go to https://model.energy/
This site finds optimal combinations of solar, wind, batteries, and a long term storage (in this case, hydrogen), using historical weather data, to provide "synthetic baseload". It's a simplified model, but it provides important insights.
Go there, and (for various locations) try it with and without the hydrogen. You'll find that in a place at highish lattitude, like (say) Germany, omitting hydrogen doubles the cost. That's because to either smooth over seasonal variation in solar, or over long period drop out of wind, you need to either greatly overprovision those, or greatly overprovision batteries. Just a little hydrogen reduces the needed overprovisioning of those other things, even with hydrogen's lousy round trip efficiency.
Batteries are still extremely important here, for short duration smoothing. Most stored energy is still going through batteries, so their capex and efficiency is important.
You can also tweak the model to allow a little natural gas, limiting it to some fixed percentage (say, 5%) of total electrical output. This also gets around the problem. But we utimately want to totally get off of natural gas.
I suspect thermal storage will beat out hydrogen, if Standard Thermal's "hot dirt" approach pans out.