bit more of it6 Mar 2020 12:28
Ground-source versions cost twice as much and need more room. RHI grants aim to refund you for the cost above that of a gas boiler within seven years.
Between 75 and 91 per cent of homes cannot simply swap their boilers for heat pumps because the houses lose too much heat, according to EPC data analysed by Worcester Bosch, a boiler maker. Heat pumps only work combined with very good insulation because they heat water only to about 50C: enough for a shower, but not the 70C central heating needs on an icy day if a house is not well insulated and loses a lot of heat. If you get a heat pump you may need to keep your existing boiler as a back-up for very cold days.
Britain’s homes leak heat up to three times faster than those of their European neighbours, according to a study of 80,000 homes by the makers of Tado, a smart thermostat.
Adding 10cm of insulation to external walls, under the ground floor and in the roof, plus double or triple-glazed windows, can cut your heating needs by 75 per cent, Palmer says (although it would cost £20,000-£30,000).
Underfloor heating and larger radiators are also good ways to boost heating.
Hydrogen boilers
Hydrogen has no harmful emissions, emitting water vapour when it burns. Mains gas, or town gas as it was known, used to be made up of half hydrogen and a mix of carbon monoxide and carbon dioxide. Towns gas was changed to natural gas from the North Sea in the Sixties and Seventies and a return to hydrogen for fuel is the silver bullet that many environmentalists are holding out for.
The government is funding research and considering a proposal from the heating industry to set a date by which all new gas boilers would be “hydrogen ready”.
In November Sajid Javid, the chancellor at the time, viewed a prototype by Worcester Bosch, which would cost £50-£100 more than existing gas boilers that sell for about £900. They would continue to burn natural gas, but could easily be switched to hydrogen in a £150 operation that would take a gas engineer an hour. You would also have to replace a gas cooker with models adapted for hydrogen, but wouldn’t have to rip out radiators or insulate to the rafters.
Yet the technology to make hydrogen on a large scale does not exist yet. Initially, natural gas would be converted into hydrogen, but that creates carbon dioxide that must be captured and stored. Experts believe any switch to hydrogen is at least a decade away.
Viessman’s Vitovalor boiler makes hydrogen from mains gas in your home and converts that into energy, reducing emissions and cutting fuel costs, but it costs from £13,000 and is the size of a double fridge-freezer.
Although it does not qualify for any subsidy, it shaves up to £900 off the annual energy bills for a five-bedroom house, says Patrick Wheeler of Vito Energy, which has fitted a fifth of the 100 or so Vitovalors in Britain.
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