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> EIA expects 13 GW of battery storage capacity to be added between the time of this report and 2025. That's like 20 power plants worth of instantly available

> EIA expects 13 GW of battery storage capacity to be added between the time of this report and 2025. That's like 20 power plants worth of instantly available power. This makes paired PV truly dispatchable. Wow.

theamk 2y ago
This is a power, not capacity though. Real power plants could produce that many GWs continiously, but battery storage can only do for a limited time. I could not find GWh figures for that particular install, but other grid-scale battery storage systems only has 1-2 hours of capacity, a far cry from real power plants.
- bastawhiz 2y ago
  > other grid-scale battery storage systems only has 1-2 hours of capacity, a far cry from real power plants There's no need for these batteries to release all of their charge at max power, though. For one, the nonrenewable power sources they're helping to replace aren't simply going away entirely. But they also only need to discharge when renewables aren't producing. The charts near the top of the article show that wind power still heavily outstrips solar in terms of capacity. What matters is that battery capacity continues to keep pace with solar such that an excess of power when it's bright out can be stored until when it's needed.
  - theamk 2y ago
    Sure, it's just that citing the batteries max power seems very misleading. This article mentions: "13 GW of battery storage capacity [...] 3 GW of natural gas additions" - so one might think that solar + battery is can power more houses than gas. And in reality, that's not the case at all. 3GW of natural gas can power (approximately) 2.5 million houses continuously. How many houses can 13 GW of battery (+ whatever amount of solar to charge them fully every day) can power? Probably way less than that, given that even in the summer, there are at least 12 hours every day when solar panels don't produce enough power.
    - bastawhiz 2y ago
      > How many houses can 13 GW of battery (+ whatever amount of solar to charge them fully every day) can power? I suppose that's the confusion; you don't have "gigawatts of battery". Batteries store GWh of energy: GW is a flow rate, GWh is flow rate for time. So at 13GWh it could power 2.5 million households for 4.3 hours or so. The article seems to use "GW" when it means "GWh" and "GWh" when it means "GWh per hour". > How many houses can 13 GW of battery (+ whatever amount of solar to charge them fully every day) can power? Probably way less than that, given that even in the summer, there are at least 12 hours every day when solar panels don't produce enough power. But it really doesn't matter. Texas uses far more power than their solar capacity can produce at any moment in time, and solar charging batteries is solar not powering homes. In the long run when renewables outstrip fossil fuels, yes, you need lots of battery capacity for the night and when the wind isn't blowing. But in the meantime, it serves a different purpose entirely. Until the point when renewables cross that threshold, much of the stored power _isn't from renewables_. Spinning fossil fuel generation up and down is slow. Besides buffering spiky demand, you use the batteries to soak up excess power as you spin down fossil fuel generation, and then keep that extra generation offline for longer (spinning it back up more slowly). When solar and wind can satisfy all demand during the day, batteries can obviously capture the excess for use at night. But it can also allow a much smaller amount of fossil fuel generation to come online at any time to fill the batteries for night (regardless of demand, because that's already satisfied). Spinning up a small amount of generation for longer is much cheaper and environmentally friendly than spinning up a lot of generation for a short amount of time.

theamk 2y ago

This is a power, not capacity though. Real power plants could produce that many GWs continiously, but battery storage can only do for a limited time. I could not find GWh figures for that particular install, but other grid-scale battery storage systems only has 1-2 hours of capacity, a far cry from real power plants.

bastawhiz 2y ago
> other grid-scale battery storage systems only has 1-2 hours of capacity, a far cry from real power plants There's no need for these batteries to release all of their charge at max power, though. For one, the nonrenewable power sources they're helping to replace aren't simply going away entirely. But they also only need to discharge when renewables aren't producing. The charts near the top of the article show that wind power still heavily outstrips solar in terms of capacity. What matters is that battery capacity continues to keep pace with solar such that an excess of power when it's bright out can be stored until when it's needed.
- theamk 2y ago
  Sure, it's just that citing the batteries max power seems very misleading. This article mentions: "13 GW of battery storage capacity [...] 3 GW of natural gas additions" - so one might think that solar + battery is can power more houses than gas. And in reality, that's not the case at all. 3GW of natural gas can power (approximately) 2.5 million houses continuously. How many houses can 13 GW of battery (+ whatever amount of solar to charge them fully every day) can power? Probably way less than that, given that even in the summer, there are at least 12 hours every day when solar panels don't produce enough power.
  - bastawhiz 2y ago
    > How many houses can 13 GW of battery (+ whatever amount of solar to charge them fully every day) can power? I suppose that's the confusion; you don't have "gigawatts of battery". Batteries store GWh of energy: GW is a flow rate, GWh is flow rate for time. So at 13GWh it could power 2.5 million households for 4.3 hours or so. The article seems to use "GW" when it means "GWh" and "GWh" when it means "GWh per hour". > How many houses can 13 GW of battery (+ whatever amount of solar to charge them fully every day) can power? Probably way less than that, given that even in the summer, there are at least 12 hours every day when solar panels don't produce enough power. But it really doesn't matter. Texas uses far more power than their solar capacity can produce at any moment in time, and solar charging batteries is solar not powering homes. In the long run when renewables outstrip fossil fuels, yes, you need lots of battery capacity for the night and when the wind isn't blowing. But in the meantime, it serves a different purpose entirely. Until the point when renewables cross that threshold, much of the stored power _isn't from renewables_. Spinning fossil fuel generation up and down is slow. Besides buffering spiky demand, you use the batteries to soak up excess power as you spin down fossil fuel generation, and then keep that extra generation offline for longer (spinning it back up more slowly). When solar and wind can satisfy all demand during the day, batteries can obviously capture the excess for use at night. But it can also allow a much smaller amount of fossil fuel generation to come online at any time to fill the batteries for night (regardless of demand, because that's already satisfied). Spinning up a small amount of generation for longer is much cheaper and environmentally friendly than spinning up a lot of generation for a short amount of time.