The current relief to 0% VAT rate on solar panels only applies where an MCS certified company manages a solar installation. This can exclude, for example, NICEIC electricians who are also qualified to install solar.
You may be interested in these active petitions
I believe solar is clearly a priority. If every house has solar, it would greatly contribute to generating enough electricity to get most fossil fuel cars off the road and replace with electric. But we need the solar first!
I believe builders working with qualified electricians on projects (extensions etc) should be encouraged to add solar to their projects.