-
Because even though it’s “renewable” all energy produced in the U.K. ends up going into a central pool and this is what sets the market supply. At the moment gas is still the greatest contributor to energy produced, so the market price goes up when gas goes up.
Many renewable tariffs are based either on REGOs (a certificate to say you agreed to buy x amount of solar energy, and this has been produced) or increasingly PPA’s where a supplier has a dedicated feed from a wind farm/solar farm etc which is a more transparent way of showing that the suppliers energy comes from renewable sources.
Explainer on why the Standing Charges are going up
https://www.theguardian.com/money/2022/mar/06/why-is-my-standing-charge-up-by-80-energy-firms-pile-on-the-agony