Battery Energy Storage System

As most solar energy will be generated during the day it is thought that storing this energy for later release will help the electricity grid balance power availability.

Despite the huge expense of these batteries the developer is proposing to build a 2 acre paddock filled with up to 18 shipping containers holding lithium-ion batteries. This will be able to store 40MW.

It can be assumed that the payment for stored power must be far more than during the day though this is guesswork as the power agreements are always confidential.

Why use Battery Storage?

The case for using battery storage is that power can be stored during the day then given to the grid when required to make up for shortages. The usual assumption is that more power is needed at night. 

The actual power figures show that there is less demand at night and more between 9am and 5pm. Presumably driven by business and industry.

The graphs show that power plants using fossil fuels drop their output at night in line with this. Renewables average out over the day and so allow the use of fossil fuels to be lower.

If renewable output is reduced during the day - being saved in batteries instead - then this will increase the daytime load on other sources. Like fossil fuels.

The tiny impact in Grid power regulation by on-site storage is not enough to justify the expense and risks involved in battery storage. Like any other natural resource lithium must be mined, processed, used, then discarded. We do not have infinite supplies and it will run out - leaving holes in the ground, toxins in the soil, and no more batteries.