I just found the calculations for using an elevated body of water for hydroelectric storage.  the capacity of imponded lakes like hydroelectric resivours is measured in acre feet, 1 acre with water 1 foot deep (43560 cubic ft).  1 acre foot at an elevation of 100 feet has a potential energy of 102 kWh.  This is not counting loss due to leakage, friction in the penstock, pump and turbine ... this is the threritical total.  So a 1 square mile (640 acres) resevour ontop of the Pallisades on the Hudson (500 ft high) that was 50 ft deep would only store 640 X 50 X 5 X 102 or 16,300 MWh.  thats only 100 hours output from a wind farm of 100 turbines.  Maybe by modifing the Niagara Falls hydro plant into a pumping / hydro plant and pumping Lake Ontario back into Lake Erie... 

Maybe we need to learn to live more in tune with what nature gives us! Large cities are a strain on all systems of society and nature.

Grizz,

I remember an article years ago, maybe in Popular Science that propoced a reversable hydroelectric plant along the Hudson River that would have a resivor on top of the Palisades that would help even out the demand in NYC.  during low demand it would use its generators as motors and pump water from the Hudson up to the top, and during high demand it would use the down flow to gen additional power.  The mani disadvantage is effecincy, only about 50% back then.  this would also only be avalable where their is a body of water near a elevated land area.

Yo Bryan - you hit the nail on the head. The storage of bulk electricity is now getting the attention of the worlds greatest minds. The new electric car batteries (lithium - I think) is one huge step forward to get away from the lead/acid batteries. I believe the lithium batteries weigh 1/3 less than the lead/acid and can store more energy per pound than the lead/acid.

Now that the output efficiency of PV panels is climbing each year and the rest of the renewable energy industry following right behind - the next huge step that must be taken is storage of electricity at a large scale. Electricity is what makes the world turn - but all the other available energy (gasoline, coal, wood, nuke, natural gas, propane, geothermal, fuel oil, kerosene, etc.) can be stored easily. Electricity storage on a scale for even a small town is still beyond tech and cost effectiveness.

Grizz

What indeed!? There are, of course, our old friends hydrocarbon based fuels but we can see their days waning even as we speak. Looking forward this is going to be a serious concern for alternative energy systems across the globe far into the future. Tesla was working on this at one time or another during his lifetime but no one knows what, if anything, he had come up with. Solving this may be the ulimate answer to energy for the human race. Huge capacitors? Batteries? I'll be interested to hear ideas on this.