Winter solstice in Edinburgh.
Sunrise was at 8:42am: Sunset is due at 3:39pm, for a total of 6 hours and 57 minutes of daylight.
(Meanwhile, over on my blog comments earnest Australians keep trying to convince me that solar power is the solution to all our energy needs. Hint: up here, demand peaks at night—for heating—not during daylight hours for cooling.)
@cstross I think giant batteries to stick the wind into are more immediately interesting.
These guys seem to have the best tech for municipal container batteries:
It's iron, road salt, water, and vinegar in a bunch of PVC pipes. It's all 1970s tech. Their patents are all around special filters (clever but still pool/aquarium level of complexity) that take it from a few hundred cycles to "the plumbing wears out long before the chemistry does".
@cstross P.S. I blogged my last research pass on them, with links to the source material:
https://landley.net/notes-2022.html#16-07-2022
Alas it isn't a home solution, it's municipal. Supplements electrial substations or attaches to an office park.
@cstross This video is the best intro to their tech I've seen so far. (Wadsworth constant 6 minutes.) Dude went to their factory and interviewed the founders.
Hm. That leaves me confused about how that's a flow battery. It seems to work by depositing ions on plate electrodes, so it should have all the issues of batteries with plate electrodes: electrode size (not volume of electrolyte) limits capacity, electrodes' surface area matters so their erosion matters.
Do you know what prevents the electrodes from getting reshaped into something with much smaller surface area over time?
@robryk @cstross I also vaguely recall that the iron being in solution is the charged state, not the discharged state? But don't quote me on that, I'm sure it's written down somewhere.
The basic technology was developed by NASA in the 1970s and is all out of patent. It was uninteresting because it's really big and heavy, and at least back then its round trip efficiency was only 75%...
https://en.wikipedia.org/wiki/Iron_redox_flow_battery
I'm not a domain expert here, I can just point at sources....
@robryk @cstross It's not an electrode it's a membrane? I've seen explanations of this but it was a while ago and there is COVID between here and there. It could have been in https://youtu.be/xCzKQbukL1E or https://youtu.be/qhtAiIMkmJY or one of https://resources.essinc.com/white-papers or...
I believe the metal completely dissolving into solution each cycle is part of the expected operation? It doesn't have the lead/acid problem of too much discharge being bad for it.