[jillesvangurp]

Anyone that needs access to cheap power. So, basically anyone with high energy bills. That's why there's going to be a surplus.

People put solar on their roof not to get rich from selling power back to the grid (though that is a nice incentive) but to avoid having to buy expensive power from the grid. For the same reason factories might put solar panels on their roofs. Car charging companies might invest in some solar panels, etc. And of course power companies themselves also like the idea of swapping out expensive gas generators for solar panels plus batteries.