Monday, August 13, 2007

Storing Wind and Solar Power


Capable of
Serious Storage

I have been directed to looking at battery storage by a good friend in West Cork who is an expert on wind power and alternative energy generally.

I have been reading up on an exciting type of high capacity battery called "Flow Batteries". These are a species of rechargeable battery where the battery fluid or electrolyte is what is charged up and hold the energy. Therefore you could take a flat battery and pour in some charged up fluid and hey-presto you got power.

You can therefore use large storage tanks for this fluid and pump it through the battery cells – increasing the capacity of the battery many times.

Flow cell batteries are a type of “fuel cell”

Redox Battery

One type of Flow Battery of note is the the redox (reduction-oxidation) flow battery this is where the fluid has all the juice dissolved in it AFAIK. The energy of this battery is related to the volume of fluid in the tanks. The power on the other hand is related to the size and number of cells.

What I think that means is:

MORE CELLS = More Volts (Size of Engine)
MORE FLUID = More Ampere Hours (More petrol in the tank)

Then the Heavy Duty Science and Chemistry Kicks In.

It all gets very-very technical and complicated after that. Suffice it to say these batteries have some serious storage capacity and are suitable for holding gobs and gobs of power derived from windmills, PV Solar Cells etc.

This is most useful because with wind turbines, much of the time the wind is blowing in the middle of the night when you don’t want the power – so it goes to waste. With a redox battery – you could store up all this nice juice and use it to cook the lunch and heat the house.

I will be writing up more as I learn it on battery storage systems.

Batteries ain't what they used to be.


No comments: