Webmaster - 24 April 2008 05:18 PM
In hopes of further education:
“Taking into account evaporation losses from the exposed water surface and conversion losses, approximately 70% to 85% of the electrical energy used to pump the water into the elevated reservoir can be regained. The technique is currently the most cost-effective means of storing large amounts of electrical energy on an operating basis, but capital costs and the presence of appropriate geography are critical decision factors.”
There you go - you were only off by a factor of what??? 80X....... 8000%. Close, but no cigar!
Doesn’t add much cred to your rantings. Why not just say “Hey, that is a cool way to store electric”.....nah, that would be a positive and progressive opinion........
Read more....
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
And, as stated, that ignores the system efficiency losses.
It’s like the pump heating contractors that sell equipment based upon AFUE.
I can sell you an 87% AFUE boiler that’s three times the size you need for your building. When that burner lights, it will run at 87% efficiency.
Of course, being oversized like that, it will waste hundreds of gallons of fuel every year. But the sticker says “87%,” so it must be a good deal, right?
If we’re talking about environment and pollution, the total efficiency is the critical number, not the efficiency of any one individual component.
Selling things based upon an efficiency number that ignores the total system is dishonest. I would never even dream of doing something like that to my customers, and you shouldn’t be doing it here, Craig.
Pumped storage like that is a cool way to store electricity, but that doesn’t make it a good companion to PV. Ferraris are a cool way to travel, but that doesn’t make them a good way for me to deliver a heating system. Being cool doesn’t make something a good idea.
(By the way, I do know a thing or two about pumped storage, as I’ve toyed with the notion of using it as a way to store power for my house. I don’t imagine that it is efficient, but rather that it may be more cost-effective than lead-acid batteries. It’s certainly not more efficient than a nuclear plant, by any stretch of the imagination.)
Joe