Charities and NFP groups can get cheaper utility bills but they need to tell their supplier. See here: https://www.ukpower.co.uk/business_energy/energy-guide-for-charities
They could also think about raising the capital from their community to install solar or biomass to cut their energy bills massively, repaying investors from the surplus they’d generate from their energy savings. Biomass heat generators qualify for a subsidy from central government,and investment in biomass is still abler to attract SITR tax relief, so you can make a reasonably compelling investment proposition to your community of supporters at a cheap cost, all told.
The Community Shares Company