"Insofar as the numbers I have presented in this paper are correct, they demonstrate that energy storage is a problem of 19th century science. No future laboratory breakthroughs or discoveries are required for solving it. All that is needed is fine engineering and assiduous attention to detail. Said poetically, this is 21st century rocket science.
Moreover, it is clear from Fig. 11 that the storage capacity of months becomes feasible once the engine (including the heat exchangers) exists as a product one can purchase at a known cost, particularly if the heat is further transferred into cheaper media for longer-term storage, such as rocks underground. Thus, pumped thermal storage with heat exchange is not a niche solution to the energy storage problem but a global one. This is the reason I think it will prevail."
The paper does contain (rough) cost estimates, specifically the cost per unit of energy storage (about $13/kWh) and the cost per unit of power (from $0.20-0.27/W depending on the choice of gas.) See section V, "Cost".
I'm not impressed with the costing methodology used, but it's probably at least in the ballpark.
In the past few years, lithium ion battery storage has plummeted in cost and is seeing massive deployment all around the grid.
Most utilities use five-year resource plans, and even then they tend to use out of date publications for cost guidance, which themselves took several years to be written and get through peer review.
So traditional utility deployment is done on 10-year old info. In more open markets, like Texas, storage is a huuuuge amount of the capital that's being deployed on the grid. And in places with more active residents that force the utility commissions to force the utilities to use realistic numbers, like California, storage is already deployed in GW range. For example, existing storage on the grid today was a bigger player than nuclear during California's recent and massive heat waves.
And one dirty secret that they don't tell you about nuclear: it's also going to need storage. Nuclear is not dispatchable, it can't be turned down on demand, and can't be ramped up. But real power demand varies a huge amount throughout the day.
The only reason France was able to get up to 70% nuclear energy on their grid was by using the continental grid to trade energy with other countries. France has a small number of super expensive nuclear "peakers" but they can only deal with very small fluctuations in demand.
So if nuclear were ever going to be a really major power source, or the only power source, it would require lots of storage to balance load.
> In the past few years, lithium ion battery storage has plummeted in cost and is seeing massive deployment all around the grid.
I advize doing the maths on this. Look at graphs of how much solar and win vary, check total elecricity consumption, look up latest price of li ion batteries and then do a bit of maths to see how much you need so that you get no blackouts in a 10 year period. Then realize you should use compressed air storage instead...
Last I checked, if we use the cheapest form of storage (compressed air) and assume there are enough suitable caves for the huge amount we want, we'd triple electricity costs by switching to renewables+storage.
> And one dirty secret that they don't tell you about nuclear: it's also going to need storage.
Not really, you just need to be able to burn excess power. Which is a very easy thing to do (you can spend as much as you want on turning atmospheric CO2 and water into methane).
I have done the math, and that's why I think that nuclear will only be a niche, and expensive, form of energy for a few countries that do not have good renewable resources.
As for CAES, if it can scale and be cheap, great. But there isn't nearly as much evidence of that for CAES as there is for batteries, which are being deployed by the GWh on the grid now, and which have massive plans for expansion in areas where the grid is market based and profit driven, instead of a regulated monopoly that can rest on its laurels.
I occasionally hear about liquid air too, and though everybody I have encountered that works on it is a bit nuts, I am more optimistic about liquid air than CAES for massive scale, as liquid air can be deployed many many places.
