The Government generates no wealth whatsoever.

It is funded 100% through taxation - either direct taxation of the wealth of individuals or the indirect taxation of the wealth of individuals by the taxation of private sector businesses - which increases the price individuals have to pay for goods and services. In this specific case, the UK energy suppliers are now charging everyone more for the energy they use to cover the costs of the tariffs which the UK Government have required they pay - without such tariffs everyone would be paying less for the energy they use.

Anything you get "free" from the government has been paid for through taxation of individuals.

Thus, this is merely a tax rebate for those fortunate enough to be in the position to install solar power generation equipment - owners of land - specifically those with buildings that have south facing roofs.