3 ms·

And now I know :) Thanks for taking the time to make this detailed & informative reply! So basically the point is that Vanadium presents the most efficient met

And now I know :) Thanks for taking the time to make this detailed & informative reply! So basically the point is that Vanadium presents the most efficient method of power storage we know of to date?

sanxiyn 12y ago
I don't think so. In energy storage, pumped-storage hydroelectricity(PSH) is still the undisputed king. It currently represents >99% of installed capacity, and has a quite good efficiency. As I understand, Vanadium redox battery is not more efficient than PSH. And no energy storage system is proven to scale to PSH scale. About the only problem with PSH is need for a reservoir and hence site selection. In Europe, it is said that Norway, which has lots of good sites for PSH, alone, can support entire energy storage demand of Europe. As I understand it is more problematic in US.
- throwawayaway 12y ago
  To what extent could you pressurize the water to restrict the volume? I can imagine an egg timer style device with heavy pressurised immiscible liquids and some turbine in the middle that you turn over physically instead of pumping. someone has already had the idea: http://www.myfreeinventions.com/electricity-generation/portable-hydroelectricity-generator-for-remote-areas-made-from-recycled-parts/ http://www.myfreeinventions.com/electricity-generation/porta... oh here's another one - might be interesting to strap two of these together: http://fivegallonideas.com/hydroelectric-generator/ http://fivegallonideas.com/hydroelectric-generator/
  - sanxiyn 12y ago
    Well, air compresses better. People are trying to store energy in compressed air. I found LightSail Energy to be interesting. http://www.lightsail.com/ http://www.lightsail.com/
  - gus_massa 12y ago
    From http://en.wikipedia.org/wiki/Properties_of_water#Compressibility http://en.wikipedia.org/wiki/Properties_of_water#Compressibi... > The low compressibility of water means that even in the deep oceans at 4 km depth, where pressures are 40 MPa, there is only a 1.8% decrease in volume. With some simplifications, the stored energy is approximately P*deltaV/2 (when P>>1atm), where P is the pressure and deltaV is the volume change. So in 1 litter (1/4 galon) at -4Km, the energy is only 400J (.1Wh), and you need submarine grade technology to store it. The potential energy of 1 litter (1/4 galon) of water at 40m (130 ft, a 15 story building) is also 400J (.1Wh) and is much easier to build.
  - pantalaimon 12y ago
    the volume of a liquid hardly changes under pressure.
- lucaspiller 12y ago
  The biggest site in the UK (built in the 70s for the same problem from nuclear power) was built into an abandoned quarry, surely there must be plenty of those around? http://en.wikipedia.org/wiki/Dinorwig_Power_Station http://en.wikipedia.org/wiki/Dinorwig_Power_Station
  - ajb 12y ago
    Yes, but probably not ones on the top of a mountain.

And now I know :) Thanks for taking the time to make this detailed & informative reply! So basically the point is that Vanadium presents the most efficient method of power storage we know of to date?

sanxiyn 12y ago

I don't think so. In energy storage, pumped-storage hydroelectricity(PSH) is still the undisputed king. It currently represents >99% of installed capacity, and has a quite good efficiency. As I understand, Vanadium redox battery is not more efficient than PSH. And no energy storage system is proven to scale to PSH scale. About the only problem with PSH is need for a reservoir and hence site selection. In Europe, it is said that Norway, which has lots of good sites for PSH, alone, can support entire energy storage demand of Europe. As I understand it is more problematic in US.

throwawayaway 12y ago
To what extent could you pressurize the water to restrict the volume? I can imagine an egg timer style device with heavy pressurised immiscible liquids and some turbine in the middle that you turn over physically instead of pumping. someone has already had the idea: http://www.myfreeinventions.com/electricity-generation/portable-hydroelectricity-generator-for-remote-areas-made-from-recycled-parts/ http://www.myfreeinventions.com/electricity-generation/porta... oh here's another one - might be interesting to strap two of these together: http://fivegallonideas.com/hydroelectric-generator/ http://fivegallonideas.com/hydroelectric-generator/
- sanxiyn 12y ago
  Well, air compresses better. People are trying to store energy in compressed air. I found LightSail Energy to be interesting. http://www.lightsail.com/ http://www.lightsail.com/
- gus_massa 12y ago
  From http://en.wikipedia.org/wiki/Properties_of_water#Compressibility http://en.wikipedia.org/wiki/Properties_of_water#Compressibi... > The low compressibility of water means that even in the deep oceans at 4 km depth, where pressures are 40 MPa, there is only a 1.8% decrease in volume. With some simplifications, the stored energy is approximately P*deltaV/2 (when P>>1atm), where P is the pressure and deltaV is the volume change. So in 1 litter (1/4 galon) at -4Km, the energy is only 400J (.1Wh), and you need submarine grade technology to store it. The potential energy of 1 litter (1/4 galon) of water at 40m (130 ft, a 15 story building) is also 400J (.1Wh) and is much easier to build.
- pantalaimon 12y ago
  the volume of a liquid hardly changes under pressure.
lucaspiller 12y ago
The biggest site in the UK (built in the 70s for the same problem from nuclear power) was built into an abandoned quarry, surely there must be plenty of those around? http://en.wikipedia.org/wiki/Dinorwig_Power_Station http://en.wikipedia.org/wiki/Dinorwig_Power_Station
- ajb 12y ago
  Yes, but probably not ones on the top of a mountain.