The most bizarre way to save money I ever read, being that it doesn’t actually save any money.
I’ve recently changed to London Power, which is 100% renewable (backed by Octopus) and was cheaper on all four metrics (gas and electricty unit prices, and daily standing charges for both fuels) than any other supplier, including Octopus.
Anyway, even if it were renewable, I don’t think we should be concerned about renewability of the fuels regarding the global warming at all. It is not their renewability that matters, but their carbon impact. For example,
Converting rainforests, peatlands, savannas, or grasslands to produce food crop–based biofuels in Brazil, Southeast Asia, and the United States creates a “biofuel carbon debt” by releasing 17 to 420 times more CO2 than the annual greenhouse gas (GHG) reductions that these biofuels would provide by displacing fossil fuels.
What I mean here is if you can dig out from the earth a fossil that has near to zero carbon footprint and not harmful in any other ways - go for it. Thorium is a good example. (I know, I know, a lot of people who has no clue whatsoever about molten salt reactors safety and footprint would argue now)