at any given time.
I find it helpful to think of electricity flow in terms of water - there are many analogous characteristics. With water in a hose, if the pressure suddenly increases the hose "gives" a little and doesn't blow up. The analogue with electricity is voltage. When the wind picks up suddenly and blows through a wind farm, there's a sudden increase in voltage, or electrical "pressure", that hits the grid. The lines can absorb some extra pressure. But if it gets too great, huge resistors are switched into the transmission lines which soak up this extra power and dump it as heat. That prevents wires from melting, but of course it's wasteful. So the utilities, ISOs (Independent System Operators) and RTOs (Regional Transmission Operators) try to smooth these voltage bumps with natural gas turbines, which unlike coal or nuclear plants can come online or go offline very quickly (in a matter of seconds). It's better than dumping the power as heat, but not much. Firing up the turbines and shutting them down makes them up to 30% less efficient than letting them run all the time.
Storage, on the other hand, with no mechanical parts to set in motion, loses very little efficiency in the smoothing process. By putting it first in the smoothing chain, you can get smooth out all of the sharp spikes, then finish the job with natural gas. It works.
There are significant problems which need to be overcome. Efficient electrical storage is prohibitively expensive. Then there's the complexity of natural inputs like wind and the sun, and the fact that there isn't nearly as much energy in these sources as people tend to think there is (geothermal and hydro are a different story).
You can see California's current supply and demand in realtime here (scroll down for renewables):
http://www.caiso.com/outlook/SystemStatus.html
How CAISO balances California's utility energy:
Edit history
Recommendations
0 members have recommended this reply (displayed in chronological order):
= new reply since forum marked as read