Comment by hnaccount_rng
2 days ago
It may never be “worth” it in economic sense, but it offers a way to separate the time of “energy is used” and “energy is available”. Assuming sufficient captureable volume you could capture the emissions of a fossil power plant during the ~two weeks per year where weather is sufficiently bad. And then take the other 50 weeks to capture that carbon again. It can be completely inefficient (like sub 5% round trip efficiency) if a) we pay for it via a capacity market and b) have sufficient excess (clean) energy to run it
The idea that we'll have huge excesses of clean energy seems like wishful thinking. We may have issues with excess energy at certain times of day for sure. But intermittent excesses like that are difficult to make use of economically because of capital costs and low utilisation. A general excess would be countered by falling energy prices to the point that it's difficult to make a business case for new installations.
I don't see a future where technologies which are massively inefficient reach their break even cost before other energy intensive activities or more efficient grid scale storage soak up the excess.
Of course it seems like wishful thinking! Because that’s the historic norm. Energy was (in some way) always the limiting factor. And every time energy access got meaningfully cheaper society massively reorganised around it.
And yes “energy” in general won’t be free. We still need to build the generation and distribution systems. But we reached a point where just dumping solar on all _new_ roofs rounds to essentially free (the costs are the labor and the access to qualified personnel). The exact same is currently happening to batteries. Any transformer project will be able to just integrate 4-12 hours of batteries without getting meaningfully more expensive. The same for every domestic or industry service upgrade
We are not there yet. But give it another 5 years and we will. And then we are only talking about financing what little distribution system we will need (basically you only need average-sized cables not peak-sized ones) and a capacity market for backup power systems (also only for average residual demand). And those we simply cannot (efficiently) finance by a per-kWh-used charge