Fascinating question, and a critically important one because of the climate crises. I implore everyone to check their own carbon footprint on one of the many online calculators. The results are startling / terrifying. I did so last week, and although my personal footprint was estimated to be 50% of the UK average, I have reduce this to (not by) one third to meet the UK average required to meeting the Paris accords. So, for that reason alone, running your heating and hot water on electricity (especially if a “green” supply) makes sense.But that aside, the financial calculations are complicated. We ran through the same issues a few years ago for a country house. In summary, gas (where available) is the cheapest to run. Then oil. And electricity is he most expensive unless either (a) you have a heat pump, or (b) you use a night tariff. But this assumes (for oil or gas) that you have a modern, condensing boiler running at optimum efficiency. The problem is, most boilers do not run at optimum efficiency, distorting a simple comparison. And oil prices are far more volatile (and likely to increase).Gas boilers (new, not existing) will be outlawed in a few years (unless running on hydrogen – where trials are already under way – but whether hydrogen is the answer to domestic heating is a totally separate issue with its own complications). Our experience was as follows:1 Gas – not available. But would have been the cheapest to run at about £1,250 a year. It would have cost about £15k to instal (because there was no existing central heating or radiators). 2 Oil. To install probably £20,000 (oil tank, boiler, plumbing, radiators). Then about £3,500 a year to run. 3 “Dry” electric system. If radiators, probably about £4,000 to install – perhaps a bit more for underfloor heating, depending on whether you have to rip up carpets, floorboards, put down a screed, etc. Then about £4,000 a year. So say £16,000 less to install but costing £500 more a year to run. It would take an oil system 32 years to pay back the additional costs.4 “Dry” electric system running on night storage heaters. If radiators, probably about £5,000 to install. Then about £1,250 a year to run (at 5.5p a kwh). So say £15,000 less to install and saving £2,250 a year. 5 "Wet" electrical system. Probably about £15,000 to install, with a massive water storage tank to act as a "heat battery", heating up overnight at a cheap rate. Probably about £2,500 - £3,000 a year to run. (And you need somewhere for the tank).6 “Wet” system with a heat pump. £40k to install (there was no existing central hearing plumbing or radiators) we could have done it for £30k, but we did not need to put in a ground system because the heat is taken from the river running through the garden). £1,250 a year to run (we use 14,000 kwh electricity a year at 12p per kwh, but that is for everything including general household). So compared to oil - £10k - £20k more to install (but Government RHI grants pays back £27k of that over seven years), and saves £2,250 a year less than oil to run. In fact, it costs about the same as gas to run (if we had gas). So the net costs of installation (after government grant) was about the same as oil, but the costs of running the system are about a third. And no smells, oil tank in the garden, vulnerability of supply. A well sized and installed heat pump, running efficiently, will generate three or four kw of heat for every kw of electricity used (and five kw if the heat is collected from a water source such as a river or acquifer). And then it depends how much you use the house. If you are only using it at weekends, it makes even less sense to pay a lot of up front costs, because your bills will be lower and you will probably never recover the additional costs. But then, unless you can plan ahead (say 24 hours to let the house warm up), night storage heaters (probably your lowest cost option overall to install and run apart from a heat pump) may not be practical because they can take some time to warm up the house. You may prefer underfloor heating just for the “on / off” convenience. As for underfloor heating – if your flat is on an upper floor, you may also be paying to heat your neighbour’s below ceiling unless you have enough ceiling height to insulate underneath (and then you must be careful that the insulation is vapour permeable, otherwise you may create a problem with vapour rising from the flat below condensing and causing rot). You could have an “air to air” heat pump (basically, an air conditioning system running in reverse), which is super-efficient but a bit noisy. If you some somewhere to put the external unit. If you have a ground floor flat, with solid floors and enough ceiling height to lose a few inches, then a screed floor can act as a thermal sink and work effectively the same way as storage heaters, so that you can heat up the rooms at a cheap rate overnight, and let the heat seep out during the day (with the occasional top up as required). Warm bathroom floors, and coming down to a warm kitchen floor in the morning is wonderful.If you can get together with your co-owners, and have room for a communal heat pump and water tank, and can agree on heat metering, then a communal solution would probably be by far the most cost effective overall. You may be eligible for RHI. You can share the ground loop, and use something like the Kensa shoebox heat pumps individually for each flat (a very effective solution – ideal for flats). Have a look at Ofem’s information about Non-Domestic Renewable Heat Incentive for “shared ground loops”.As for power cuts – they are very rare nowadays. And they generally last less than an hour when they do happen. As you say, they will also stop an oil or gas system working. So not something to worry about. As for wood burners, they are super polluters to be avoided. So – answer overall – I would say “yes” it makes sense to go electric to heat your flat. It particularly makes sense if you are only using the flat part time, because the increased energy costs will be set off against the reduced installation costs. And a communal heat pump system (ground, water or air source) probably makes most sense of all, if you have large grounds to collect the heat from, or somewhere to put the air source collector outside (away from the house because they can hum a bit) and either a ulities room or outhouse for the heat pump, or use the Kensa "shoebox" units in each flat. But, heat pump systems work best by keeping the house at a constant temperature, not for "on / off" heat.But then the question is “which electrical heating system”. To which the answer is “it depends”.
T P Howell ● 1903d