The electricity that come off windmills is lousy with spikes and dips because of the way turbulence effects the power generated by the blades. if the windmills were pumping water or compressing air these variances in energy capture would be of very little importance because the electrical generation would come from stored energy. Had the Wind Energy enthusiasts gone this way from the start they could have become a reliable peak load producer and the price the charged for the electricity would have been nicely profitable for the producer, and reasonable for the utilities at the same time because of the expense of other peak load generating systems. I like pneumatic because those towers would make a dandy air tank.
Unless and until we find a low cost, long life battery, I imagine that it would be less expensive, and more effective, to employ a smart-grid and smart-home/building approach that will throttle demand quickly, down or up, as a means of "storing" or "releasing" electricity. For example, if the wind were blowing especially hard for a short amount of time, the utility provider could signal (via 3G or FM radio subcarrier or the 'net or whatever) the customer's home or building controller to temporarily use more, or less, electricity. The air conditioner could come down or up 0.5 degrees F, the electric water heater could climb 5 degrees, etc. A network of large buildings with hydronic heating and cooling systems could engage thermal ice storage systems. It would be turned on when power was in excess and the ice would be consumed when power was in short supply. 300 gallons of water, converted to ice, stores about 90 KWH of electricity. Of course, the quintessential storage application would be thousands of parked electric cars, all tied to their chargers, waiting for cheap electricity to begin, and then getting an unexpected price break in the middle of the day whenever the utility has extra power on its hands. This is to say that electric cars enable the use of much more wind and solar power.
The Skud
I agree with Slowburn - raising water for hydro power or some sort of compression system for air, with turbine use later would have been a better option. Windmills - and solar panels - were sold to the public as cheaper (and 'greener') than coal-fired power, but will always suffer from gaps in the wind or sunshine supply, making them intermittent at best without storage.
The Gizmag article titled "Graphene-based supercapacitor a step closer to commercial reality" represents a solution for storage of excess power from wind power sources.
No doubt the scientists who conducted this research were not informed of this development as this newest technological breakthrough is too new for their consideration.
Sascha Humphrey
Of course energy storage doesn't have to involve batteries or their like, you can store energy in form of hydrogen for instance!
Димитър Мирчев
Assuming we add grid energy storage only for the purpose of storing energy this may be true.
But utilities and end consumers add batteries for various of reasons and storing energy is not even the main one.
@JoeT, I really like your idea. The electric water heater alone would probably make it worthwile. Heating the water of thousands of households when you have the energy would definately lead to a much reduced peak power demand.
Siegfried Gust
Agree that using the tower of a wind mill for energy storage seems to be an obvious next step in their development. But pumped fluid storage seems like it would be inherently for efficient than compressed gas systems due to losses associated with heat created during compression. I could even imagine a system that worked by raising and lowering a weight inside the tower that might have an efficiency advantage due to the direct mechanical linkage made possible that way.
@ Sascha Humphrey Did you read the article only 5% of the solar energy was converted to hydrogen. Using platinum as the catalyst it take 1.8 watt hours of electricity to produce 1 watt hours worth of hydrogen. Then you have to compress it for storage.
Bob Stuart
There is also a big environmental cost to not storing wind power that should be factored in. As more renewables enter the system, the need for storage and baseload increase. It makes sense to use wind to pump water directly, and generate hydropower on demand. Operating a short inclined railway for tankers would be a good match for kites, and there are locations where reservoir facilities are underused.