Grants and Financial Help
The UK government will from time to time offer inducements to nudge your behaviour. These range from cycling and electric car nudges to home energy nudges. They change from year to year. Most of the schemes are run by Ofgem.
Renewable Heat Incentive RHI
This scheme is not means tested and helps to offset the cost of a new heat pump. The upfront cost of a heat pump is high and this incentive pays back the householder a bit every year which over 7 years equals the installation cost. There is also an official Renewable Heat Incentive Calculator to help with working out the payback
The Energy Company Obligation ECO
This is means tested and provides insulation and energy efficiency technology to low income households. See link here.
The Green Home Grant 2020
Details are provided here on the government website. Possibly starting in September 2020.