Green Energy

2193 readers

80 users here now

everything about energy production

founded 2 years ago

MODERATORS

poVoq@slrpnk.net

SteveKLord@slrpnk.net

117

Solar Photovoltaics with Battery Storage Cheaper than Conventional Power Plants (cleantechnica.com)

submitted 2 months ago by silence7@slrpnk.net to c/energy@slrpnk.net

14 comments fedilink hide all child comments

I'll note that aggregate system cost still benefits significantly from including wind and other non-solar sources of energy; having a mix of different intermittent sources (and some firm generation such as geothermal) means less storage is needed.

you are viewing a single comment's thread
view the rest of the comments

[–] Aurenkin@sh.itjust.works 4 points 2 months ago (5 children)

How does solar + pumped hydro compare? I thought I read somewhere the cost of pumped hydro per unit of storage was crazy cheap (assuming suitable enough sites are available). I think that kind of system probably makes a whole lot of sense too for places where the geography allows.

[–] jol@discuss.tchncs.de 3 points 2 months ago* (last edited 2 months ago) (2 children)

Pumped hydro is great for taking advantage of the geography but it's thousands of times less energy dense. There was this guy that made a pumped hydro water tank on his roof and by his calculations a cubic meter of water was equivalent to a AA battery. A professional damm might be a bit more efficient though.

I'm looking forward to see more heat based storage, like molten salt, heated sand, or pumped geothermal.

[–] sushibowl@feddit.nl 4 points 2 months ago (1 children)

There was this guy that made a pumped hydro water tank on his roof and by his calculations a cubic meter of water was equivalent to a AA battery.

That sounds crazy. Let's do some math. From what I can find, a double A battery contains about 10-14 kilojoules of energy. Let's use 14 to be charitable.

A cubic meter of water weighs about 1000kg. We know the formula for potential gravitational energy U = mgh. So if we used all the energy from the battery, we could lift the water:

14000 = 1000 * 9.81 * h
h = 14000 / (1000 * 9.81) ≈ 1.43 meters (4 feet 8 inches)

That assumes 100% efficiency of course. Still, lifting a ton of water even two feet ain't nothing to sneeze at. Batteries have a lot of energy.

[–] jol@discuss.tchncs.de 2 points 2 months ago

Thank you for doing the math! I think this was the video of the fella doing his water tank battery: https://youtu.be/CMR9z9Xr8GM?si=go28fQ6DYXyW1GTi

load more comments (2 replies)