RE: E V battery news3 Sep 2019 11:35
It is effectively a form or arbitrage, but in time rather than space. You charge your batteries when energy is cheap (such as overnight) and them sell back to the grid during peak times. Clearly you would need to be on a tariff that varies by time of day, but these are becoming increasingly common.
In terms of green credentials, typically wind power happens whenever the wind is blowing, regardless of whether or not the demand is there, so being able to store this energy is a good thing. We would effectively be able to use the UK-wide EV fleet as a large distributed storage mechanism.
Yes, there are always losses in converting energy from one form or another, but this is better than having to constrain off renewables at times of low system demand.