Just under 6 per cent of the 21 million heating systems installed in Germany are heat pumps; the vast majority of households use oil or gas boilers. Berlin wants newly installed systems to be at least 65 per cent powered by renewables from next year. Tipping point Greater success has come in countries where the financial incentives are clearer. The gas price crisis in Europe last year helped trigger a “tipping point”, the European Heat Pump Association said: sales grew by 39 per cent in 2022, with almost 20 million pumps now installed in Europe and the UK. National rates…