How does battery storage support frequency regulation on the grid? And how is the battery storage operator compensated?
In: Engineering
Electricity can not be stored in the wires. When you start using electricity it have to be made at that moment. And the amount of electricity sent to the power grid have to match the amount of electricity used exactly. The beauty of the AC grid is that this is done purely mechanically. The generator anchor and the turbines in the power stations are mechanically linked to the frequency of the grid through the magnetic inductance of the generator. So the turbines move at exactly the same speed as the frequency of the grid. This means that when you start using electricity you load the grid and the energy is taken from the rotation of the turbine. This happens at the speed of light and without any control circuits or human interaction.
The problem we are facing is that a lot of the rotational mass in the power grid is provided by coal and gas power stations. And these are becoming too expensive to operate. They are instead replaced by solar panels and wind turbines which do not have the same rotational mass directly connected to the grid. A lot of places might end up with too little rotational mass as they do not have enough nuclear, geothermal and hydroelectric power stations to provide this rotational mass. One propposed solution is to connect batteries to the power grid. However these can not mechanically be connected to the grid like the turbines but need to go through big complex control logic to supply the exact amount of current that is needed and at the right time.
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