If my neighbor has solar panel but is at work all day, then the spare power produced is sold back to the grid, typically at low rates of return. But if I'm at home & want some extra power to fire up machines in my workshop, I would have to buy that from the grid at full cost.
But what if I could directly purchase my neighbors production?
He earns more, I save some. A win-win.
That appears to be exactly what Fujitsu appear to have been testing.
Other P2P systems have been around, but have typically been shut down by the energy providers for obvious reasons.
With a large company like Fujitsu involved maybe that will change.
https://www.coindesk.com/fujitsu-claims-40-efficiency-boost-for-blockchain-electricity-exchange