Here’s One That really Exists! ‘CAES’
http://www.youtube.com/user/powersouthenergy?blend=4&ob=5#p/a/u/0/dGd7PIC09AM
If you want to know something about electrical energy production, ask the experts who make it at the wholesale level.
Notice their mention of efficiency. We need understand that they are declaring their CAES system efficient relative to other energy storage schemes, and with the help of their huge economies of scale and possibly a huge amount of waste heat from an adjacent convention natural gas turbine to help heat the compressed air coming out of storage. The losses in such a system are still significant, but they are charging their storage facility with surplus (inexpensive) KWHs off peak, and they are selling the peak hours for far more money than most people understand.
Glue Sniffers and Flower Children alike are attracted to the Indian Air Powered Tata Nano, a car that was announced to go into production some years ago, but still a pipe dream do to the fact the car is totally impractical. For those who measure the losses in the overall effort to charge the air powered car, they understand the staggering losses, and just how much fuel you still need to burn aboard the car to put the compressed air to work.
G
George,
I won’t take to time to read this one due to the fact that it’s a sore spot for me. I had a guy swear up and down that storing energy this way was okay since he was getting it for nothing. I’ve had to feed compressors to run tools and I know what the turn around is….
BAD !!
OOE
Well I suppose if you could find a source of energy, like some factories hot air exhaust, or capital buildings, that was going to waste, you could use it. Yes it might be inefficient but its lost energy anyway, put it to some use.
Interesting. Sort of like a hybrid car. Available energy is stored, then used during times when demand exceeds the capability of the main plant to provide.
Quinn, Excellent analogy.. losses are significant but there’s a margin to play, or in case of dynamic braking, it was energy lost all together, so a loss is still an gain. Big Commercial GAS turbines are VERY inefficient under light loads, might as well add some load and charge CAES..
CAES relies on the fact that a wholesale provider of KWHs can often ‘charge’ the system with 10 cent KWH of energy, and then charge a dollar for a KWH produced from CAES at peak usage (example). Don’t even think it’s a low loss storage system.
it all comes down to heat losses with compressed air, now if…
you compress the air into a very large vessel during the night time hours using an energy source that is as near free as possible (such as a wind turbine) and then harvest the air the next afternoon when the tank (which is ideally painted black and sitting in the full sun) the efficiency ought to be a bit better.
its hard to imagine the overall efficiency being much over 60% even with the sun helping out with heat losses, but the system lifetime cost vs stored energy returned probably is a bit better than lead acid battery energy storage.
one thing for sure, the air battery (storage tank) will not be damaged if left dead for any length of time.
not sure how to make it work for powering a car though, i will leave that to someone smarter than i am. 😉
bob g
I think we must have different definitions regarding overall losses, and free..
i should have quantified my statement
rather than “free” sources of energy i might have better used
“lower cost” source of energy.
compressed air systems in my experience are very low efficiency
not too many other methods of drilling a 3/8″ hole require a 4hp motor!
bob g