While there are well-established technologies to produce electricity without fossil fuels, decarbonisation of heat is struggling to get under way. Recommended strategies include expansion of low carbon networked heat and possibly the decarbonisation of gas – though these are still only happening at a scale (and with dubious carbon credentials, see PH+ Iss 15 – district heating). However, the commonest proposed means for decarbonising heat is via electrification.
Electrification of heat raises a number of questions about the ability of our power systems to produce enough low carbon electricity and their capacity to transmit it. But it also represents something of a u-turn in building services design.
Electricity is still generated in large part from burning fossil fuels – including some high-carbon coal — in power stations that lose more than half the energy as heat. For this reason electric heating – particularly direct electric heating – has had a well-deserved reputation for being high carbon and inefficient, to be avoided or replaced as a matter of course.
But things are changing – very fast. Thanks to Passivhaus in particular, fabric heat demand can be dramatically lower than it was in the ‘bad old days’ – and electricity is decarbonising at a pace: the UK has recently even enjoyed a couple of entirely coal-free days of generation.
Is it time for a rethink of the place of electric heating?
Click to view or download the pdf Together in Electric Dreams, written for Passive House Plus (issue 19)