In the UK, payments for Solar generated power fed to the grid is through Feed In Tariff (FIT) payments.
New Solar installations in the UK with Smart Metering can be paid for the actual energy exported.
Older installations - which will include lots of early adopters who are the kind of people who also use Home Assistant - are paid based on “deemed export” for which the calculation is based on the Solar generation.
It would be really nice to calculate the expected FIT payments and include these in the “money” column on the Energy dashboard.