Re:Lithium battery costs have fallen by 98% in three decades
by simonh on Saturday April 03, 2021 @06:56PM
(#26685478)
Build enough PV to generate 24 hours worth of power for the reactor in daylight hours, and store the excess in batteries to power the reactor overnight.
Re:Lithium battery costs have fallen by 98% in three decades
by taneq on Saturday April 03, 2021 @08:05PM
(#26685857)
At that point, just use battery storage and bypass the reactor entirely.
Re:Lithium battery costs have fallen by 98% in three decades
by Qwertious on Saturday April 03, 2021 @09:01PM
(#26686103)
For domestic day-to-day consumption, absolutely.
The main argument for hydrogen AFAICT is that it can be exported overseas or stored for inter-seasonal use.
Batteries can't do that, as 1) when compared to literal rocket fuel, they're impractically heavy to put on a cargo ship for bulk transport, and 2) batteries trickle-discharge so after a month or two the battery will be flat.
Re:Lithium battery costs have fallen by 98% in three decades
by ben_w on Sunday April 04, 2021 @07:28AM
(#26688585)
In fairness, pure hydrogen is also leaky and hard to work with. That’s why I was asking about the economics of turning it into methane… and yet, one of the other replies I got pointed out that methane is also a bit leaky, so we might want to reform it (or whatever the word for “opposite of cracking” is) all the way up to a room temperature liquid.
I barely remember the process from school, something like this rings a bell: https://en.wikipedia.org/wiki/Catalytic_reforming
While true, my point is that when combined with the fact that we are pre-inflection point, and the economics now stand on their own (renewables, Electric Vehcile TCO and various Energy Storage applications being already cheapest, competitive or very close too) it is not unreasonable when mapping out the 5-15 year future to bet on an acceleration of cost declines over a deceleration. Particularly because the actual driver of unit cost declines (Wrights Law/Moore's Law) is the doubling / magnitude of units manufactured and put through the system, for which with all the factories being ramped up and planned - point to the positive in my view on it.
Regarding your PV-powered and electrolysis-Sabatier (electrofuel) methane, I think there are two important considerations. In order for methane (or other e-fuels like hydrogen or longer chain hydrocarbons) to be made economically, the capital cost of the equipment needs to be utilized as close to 100% of the time as possible. We already know that PV excess will be centered around the daytime peak (5-7 hours per day) meaning that there would also need to be plenty of excess wind to balance this out to get anywhere close to 100% utilization of the excess energy. Until the electricity grids get sufficiently saturated with renewables broadly, most e-fuel applications will continue to not be competitive, particularly as things like energy storage applications (possibly run off an e-fuel) are likely to be economical prior there being an opportunity for the export of excess e-fuels. That's more at the a end of the S-Curve as far as I can tell.