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> you can't keep power as inventory Sure you can. Using compressed air, springs, pumped water and other such simple techniques. It just takes additional invest

> you can't keep power as inventory Sure you can. Using compressed air, springs, pumped water and other such simple techniques. It just takes additional investments that haven't been worth it. Maybe this is changing.

PeterisP 12y ago
None of these things work at a reasonable enough scale. You can't put a gigawatthour in compressed air or springs; pumped hydro is a possibility if you have a huge enough suitable reservoir. If we'd want to have all our energy coming from renewable resources, then you'd need stations a hundred times bigger (or a hundred times more) than the current pumped hydro reservoirs, and creating them would be an ecological nightmare, most likely requiring a destruction of a major river or lake for each such station.
- vidarh 12y ago
  Tianhuangping Pumped Storage Power Station has a 13GW/h storage capacity and about 2GW generating capacity, using two 6.8 million m^3 reservoirs - one artificial, and one built on the Daxi Creek, separated by about 900m of pipes (but I believe the vertical drop is about 600m). (if you're curious, that adds up to about 1/7500th of the worldwide average usage in 2008) If you assume 50m high structures (the lower dam is actually 72m), the area required for each reservoir is "only" 136,000 m^2. With only 20m tall structures, you need about 340,000 m^2 That's within range of the largest buildings (e.g. Boeing's largest factory has a surface area of about 400,000 m^2, and a volume of 13,3 million m^3; Tesla's factory covers an area of about 510,000 m^2). Of course this is assuming you can find somewhere suitable to give you a 600m drop, or water volume required grows quickly. But the system could be mostly closed to reduce the need to be straight on a major river. And in Japan there's pumped storage plant with a 250,000m^3 pool 500m below ground, so clearly it does not need to be a matter of building one of the reservoirs 600m up a mountain side like with Tianhuangping. To the extent the ecological risk is massive, it's because it's presumably far cheaper to pick a suitable river and dam it than having to build two fully artificial reservoirs.
- ZeroGravitas 12y ago
  If you wanted to expand hydro in the US, you could do so by starting to add generators to dams that already exist but don't have them yet. Won't be the sole solution to energy storage, but it'll help.
- lotsofmangos 12y ago
  There are a few possibilities for grid-scale storage. Lightsail energy are planning compressed air storage at grid-scale and say they can get 750kWh of storage into a shipping container format, or much more underground by using caverns emptied by the oil and gas industry http://www.lightsail.com/ http://www.lightsail.com/ There is also Gravity-power who are planning underground mass storage in the 160MWh range http://www.gravitypower.net/ http://www.gravitypower.net/ And Isentropic, who are using hot gravel storage to build a 6MWh plant in the UK Midlands http://www.isentropic.co.uk/ http://www.isentropic.co.uk/ Also, there are developments in chemical storage like the Ryden battery, which could bring battery costs low enough to just put storage where the power is being used - http://powerjapanplus.com/ http://powerjapanplus.com/

PeterisP 12y ago

None of these things work at a reasonable enough scale. You can't put a gigawatthour in compressed air or springs; pumped hydro is a possibility if you have a huge enough suitable reservoir. If we'd want to have all our energy coming from renewable resources, then you'd need stations a hundred times bigger (or a hundred times more) than the current pumped hydro reservoirs, and creating them would be an ecological nightmare, most likely requiring a destruction of a major river or lake for each such station.

vidarh 12y ago
Tianhuangping Pumped Storage Power Station has a 13GW/h storage capacity and about 2GW generating capacity, using two 6.8 million m^3 reservoirs - one artificial, and one built on the Daxi Creek, separated by about 900m of pipes (but I believe the vertical drop is about 600m). (if you're curious, that adds up to about 1/7500th of the worldwide average usage in 2008) If you assume 50m high structures (the lower dam is actually 72m), the area required for each reservoir is "only" 136,000 m^2. With only 20m tall structures, you need about 340,000 m^2 That's within range of the largest buildings (e.g. Boeing's largest factory has a surface area of about 400,000 m^2, and a volume of 13,3 million m^3; Tesla's factory covers an area of about 510,000 m^2). Of course this is assuming you can find somewhere suitable to give you a 600m drop, or water volume required grows quickly. But the system could be mostly closed to reduce the need to be straight on a major river. And in Japan there's pumped storage plant with a 250,000m^3 pool 500m below ground, so clearly it does not need to be a matter of building one of the reservoirs 600m up a mountain side like with Tianhuangping. To the extent the ecological risk is massive, it's because it's presumably far cheaper to pick a suitable river and dam it than having to build two fully artificial reservoirs.
ZeroGravitas 12y ago
If you wanted to expand hydro in the US, you could do so by starting to add generators to dams that already exist but don't have them yet. Won't be the sole solution to energy storage, but it'll help.
lotsofmangos 12y ago
There are a few possibilities for grid-scale storage. Lightsail energy are planning compressed air storage at grid-scale and say they can get 750kWh of storage into a shipping container format, or much more underground by using caverns emptied by the oil and gas industry http://www.lightsail.com/ http://www.lightsail.com/ There is also Gravity-power who are planning underground mass storage in the 160MWh range http://www.gravitypower.net/ http://www.gravitypower.net/ And Isentropic, who are using hot gravel storage to build a 6MWh plant in the UK Midlands http://www.isentropic.co.uk/ http://www.isentropic.co.uk/ Also, there are developments in chemical storage like the Ryden battery, which could bring battery costs low enough to just put storage where the power is being used - http://powerjapanplus.com/ http://powerjapanplus.com/