The Naylors’ four-bedroom home in Milton Keynes acts like a mini-power station after retrofitting solar panels, a battery and a heat pump

Clare Naylor paid close attention to how much energy she and her family were using last winter, filling hot-water bottles and bringing out extra blankets to ensure they didn’t go over budget. This year, she won’t have to worry as she is guaranteed not to receive a bill.

While millions of British households face the highest energy charges in three years from this week after a 4% rise in the price cap, and predictions of a 16% increase in January, upgrades to Naylor’s home mean she will not have to pay a thing.