[sr4402]

A big problem with large scale storage is losses. How much in loss do you get say from taking Wind, putting it through storage and then back onto the grid? What is the percentage of loss?

I knew a storage facility in the 1970 call Crater Lake. Excess power was used to put water up to a mountain lake, then when needed though Hyrdo generators. Don't know how efficient that was. But how efficient would lake storage be in comparison to batteries? And how long would the storage last in comparison?

These are the engineering questions needed lest we have another Solyndra.

[thackney]

Pumped Hydro storage is the most efficient and economic energy storage system over a long period of time with daily cycles. The efficiency of this system is typically between 70% and 85%.

http://www.electricitystorage.org/technology/storage_technologies/technology_comparison

[thackney]

Pumped Hydro storage is the most efficient and economic energy storage system over a long period of time with daily cycles. The efficiency of this system is typically between 70% and 85%.

http://www.electricitystorage.org/technology/storage_technologies/technology_comparison

[FreedomPoster]

Power companies have been doing hydro pumped storage for at least a few decades now. Georgia Power does it in Middle Georgia. The technology is well known, and I know they know the losses. I want to say the overall efficiency is in the 65% range.

They use it to run base-load nuclear and coal plants all night at higher load factors pumping water, then do peaking power with the hydro during the day.

And Wiki says 70% to 85%, so I was off a little.

http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity