Germany has many large wind mills. The gear boxes and generators are expensive. The problem is there is no way of storing the energy. When the wind blows there is not always a need for the power.

Here is a relatively low cost way of storing the energy. The wind turbines are used as water pumps similar to oil pumps. No gear box.
No generator. The generator is replaced by a simple large water tank on top of the pylon to store the energy.

The ground level water tank can be a lake. The water is recycled.

Many turbines can feed the same generator.

Paul & Robin Lamar in Germany

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Hi Paul;

It's a good idea - called pumped storage hydro that is not used as much as it could-should be for load balancing the grid...
There are a few examples of coupled PSH + nuclear running 100% of the time to good effect to effectively double peak output for a fractional increase in capital costs.
Conservation is only lip service...some foolish generators actually PAY others to take excess power!

Cheers
Cary



In many places, such as the wind farms in Tehachapi, the windmills are already on hills in order to make the most of the available winds. In those locations, you wouldn't have to build tanks on the windmill pylons. You can take advantage of the natural elevation of the hilly areas to achieve the same thing.

Of course, the round-trip energy efficiency of the water pumping and hydroelectric generation is probably only 50 percent, but that's better that's a lot better than nothing.

Csaba Csere

I might add the higher the water storage the greater the potential energy recovery.
I know you know that Csaba so that is for the none engineer among us.

Paul Lamar



Paul and all,

I did some calculations and would appreciate you engineer types to check my work:

34000 liters is almost 9000 gal.

34000 liters = 34000 kg.

34000 kg x 9.81 m/s2 = 333,540 N.

Assume 30 meters high average potential energy.

333,540 N x 30m ~ 10,000,000 J or about 2.8 Kwh.

Assume 71% (unrealistic) overall efficiency and you get 2 Kwh.

Ten tanks of water will yield enough energy for one small house for one day.  100 such tanks storing potential energy for a windless day would provide power for about 10 small houses for one day.

Please check my calculations and tell me where I am wrong, because while I love this idea, it does not seem realistic for the cost of construction of the windmills, tanks, etc.

Norm DeBoer

Not a new idea....out of college in the late 60's I was an engineer on a pump storage hydro project in western MA. Reverse turbines (buried in a cavernous room beneath the mountain) pumped the water to the top of a mountain via drilled tunnels thru the granite late at night when demand was low for electricity....then the turbines reversed into generators and the water fell back down thru the tunnels to make peak load power....actually pretty common........load levelling.
Marc



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