It's worth just mentioning that the price for electricity in the UK today is going to hit an all time low of -20p/kwh (well 19.something).

So octopus energy will pay people on the agile tarrif to use electricity.

It's due to the number of wind turbines going up, being a summer month so demand is less and it being a windy day.

The real significance is that it's a price signal to grid storage companies.
With an increase in frequency of these events, the viability of grid storage increases.