Depends what you mean by "renewable" - some suppliers seem to think electricity generated by coal or gas, but "offset" but purchasing certificates (REGOs or ROCs) from elsewhere counts, others only deal direct with renewable generators. Some include nuclear in the definition, others don't. Some just match renewable demand with renewable supply over a year, others try to match it for each half-hour.

For domestic, Good Energy for example are currently asking 23.16 p/kWh on a domestic tariff (compared with the Ofgem price cap of about 25p).

I don't have any figures for industrial - traditionally it was much much lower per unit than domestic, but the situation over the last couple of years may well have changed that (the price cap for example only applied to domestics). For larger customers there might well be an amount of haggling involved too.

Note also that there's a rather odd central market for electricity in the UK where the half-hour price is set pretty much by the most expensive generator needed at that moment to keep the grid in balance - and renewable suppliers are subject to that as well, so you can have odd results like the increase in gas prices making renewables more expensive.

   - Andy.

Thank you Andy for your answer.

You mention the price cap set by Ofgem: is there a link with public information where I can review this data?

Thank you very much

 - Gianni 

Try:https://www.ofgem.gov.uk/energy-price-cap

  - Andy.

Thank you very much Andy

Gianni