Where's the hydrogen come from?
Power-to-h2-to-power is 30% efficient.
Please.
Power-to-h2-to-power is much better than 30% efficient, btw.
Source for the "much better than 30%" efficient ? I want something that is deployed and in production. Not some kind of startup-that-will-change-everything tech.
- The technology to convert power to hydrogen and back to power has a round-trip efficiency of 18%-46%, according to data that Flora presented from the Massachusetts Institute of Technology and scientific journal Nature Energy. In comparison, two mature long-duration technologies, pumped-storage hydropower and compressed air energy storage, boast round-trip efficiencies of 70%-85% and 42%-67%, respectively. Flow batteries, a rechargeable fuel cell technology that is less mature, have a round-trip efficiency of 60%-80%. https://www.spglobal.com/marketintelligence/en/news-insights...
- https://www.volkswagenag.com/en/news/stories/2019/08/hydroge...
I hope you were assuming a combined cycle power plant was being used to turn the hydrogen back to power, not a simple cycle turbine only 2/3rds as efficient.
There are other storage technologies with higher efficiencies, but they also have much higher cost per kWh of storage capacity. On that metric batteries are like two orders of magnitude more expensive than hydrogen (flow batteries somewhat better but still much worse than hydrogen.) In storage use cases where it is appropriate (seasonal, rare event backup), hydrogen is hard to beat.
I get the feeling you're reading from a list of debunked pro-nuclear talking points.
I fail to see how this argument is "debunked". I'd also like to see what other arguments are on my supposed list.
[1] https://en.wikipedia.org/wiki/Energy_return_on_investment
The EROEI of nuclear is 106, by the link I previously provided. The very best solar installations have an EROEI of 7. That means nuclear gives 106/7 = 15x more energy output than solar, for a given amount of manufacturing energy input.
It's a simple ratio calculation, I'm not sure why you decided to subtract the reciprocals of the two numbers.
> Once EROI is high enough
The EROI of solar is 7, which means you get 7 units of energy output for every unit of energy expended in manufacturing. That is a terrible return. In no way is that "high enough". In fact, we shouldn't be bothering with it at all.
That sounds like a regurgitation of Ferroni and Hopkirk's analysis, which has been well debunked,
https://www.nrel.gov/docs/fy17osti/67901.pdf
The estimate for EROI of PV IN EUROPE is somewhere around 8, and of course Europe is a terrible place for solar -- the EROI for PV in a sunnier place, like Chile, Namibia, or the middle east, would be nearly twice this. If energy costs were really important, one would not put the PV factory in a place where energy were expensive.
That the EROI of solar is adequate should be obvious because the economic return on investment is good. If solar in Dubai can come in at less than $0.02/kWh then the energy cost (which will always be just a small fraction of the total manufacturing cost) will be reasonable.
Attempts to show PV has bad EROI very often run into methodological problems, extending the system boundaries beyond what analyses of the competing systems use (if you extend the boundary far enough, to the whole society, in steady state the EROI always converges to 1, since all energy produced is consumed somewhere. This is not a meaningful result.)