There isn't any, that's the problem, and it's not new.
Because there's such a large level of wealth inequality, we've had a situation for years in which the poor struggle to heat the home whilst the rich can afford to waste fuel, and you can't fix that with a single rate tariff where the 10,000th kWh costs the same as the 100th kWh, because attending to one problem exacerbates the other. What's needed is a progressive tariff so that it's affordable to use a sustainable amount of fuel, but cripplingly expensive to be profligate, but what we actually have is a regressive system, where the standing charge means a light user is paying proportionally more than a heavy user: the rich and profligate are subsidised by the poor and frugal. The price per kWh needs to rise in bands according to how much you're using, the same way income tax does, and the standing charge needs ditching.