At the moment low income households can get a 100% grant to cover solar install. If you aren’t low income then you can benefit from 20% discount plus very favourable Feed In Tarrifs (the amount the grid pays you for generated electricity). Plug-in solar will soon be available opening up the market to very low cost installs for people with balconies but no other outside space.

For heat pumps they pay the first £7.5k of the install.

So in answer to your question, it does make sense and they are doing it.