TOPPING OUT - GERALD COLE

Home heating

Routes to the all-electric home

Those of us of a certain age or, as I prefer, those with enhanced life experience, rarely have fond memories of electrical heating.

They tend to involve crouching over a single-bar fire in a draughty bedsit, waiting for an immersion heater to produce a bath full of warm water or waking in a muck sweat at four in the morning when an electric storage heater produces its maximum heat output – only to shiver 12 hours later when that output is exhausted.

The irony, as modern electrical heating manufacturers are keen to point out, is that electricity is 100 per cent efficient. Every unit of electricity that reaches an electrical heating system goes into producing heat. Unlike Britain’s most popular heating fuel – gas – which only releases its heat on combustion, a process that, at best, is around 90 per cent efficient, and often much less.

But the most important difference, of course, is in unit cost. At the time of writing the average price of domestic electricity is almost 400 per cent higher than gas, while the gas daily standing charge is around 60 per cent cheaper than that of electricity.

Why is that so? One main reason is that roughly a quarter of the average domestic electricity bill consists of environmental taxes, compared to a small fraction of average gas bills. The tax provides investment in renewable sources of energy, including wind, solar and nuclear, all of which are intended to replace fossil fuels by 2050 – by making most UK homes all, or near all, electric.

New homes must be gas free from 2025; no time at all if you’re currently planning your build.

So what will that involve? To the government, at least, it primarily means fitting heat pumps. To that end, it launched the Boiler Upgrade Scheme (BUS) this April, offering grants to householders of £5,000 for air source heat pumps and £6,000 for ground source heat pumps.

The only problem is that air source pumps – the easiest to install – currently cost around £10,000 upwards. In other words, with BUS, from between twice to 10 times the cost of a gas boiler.

So what are the electrical alternatives?

Modern storage heaters

Traditionally these consisted of bulky metal cabinets of ceramic bricks, heated by cheap overnight electricity and giving up their heat by day at a steady but uncontrolled rate. Since 2018, however, further controls have been required, including programmable thermostats, boost functions, fans to increase heat flow and wifi controls.

Most are also much slimmer, resembling conventional radiators. You’ll need an electricity contract offering a low-cost overnight rate and an electrician to wire in each panel.

Radiant panels

These use infrared radiation rather than the convection employed by traditional radiators. Like the sun’s rays, infrared directly heats objects in its path, including people.

The panels are very slim and light, enabling them to be fitted on ceilings as well as walls, where they can be disguised as mirrors or artworks. Panels are simply plugged into the nearest power point, though, according to a recent report, linking panels and sensors in a computer controlled system can cut energy usage by over half compared to convection-based electric space heating and by three per cent compared to an air source heat pump.

Electric boilers

Electric boilers have been around for some time, offering combi and system versions, just like their gas equivalents, and they can easily fit into existing pipework and radiator systems. They don’t, however, require flues so can be sited anywhere and maintenance is minimal.

Their main disadvantages are the cost of electricity and their smaller kilowatt outputs compared to gas boilers – an average of around 15kW compared to 20kW plus. Larger output models are available but may exceed the capacity of your home’s electricity supply which will require a costly upgrade.

Watch out, though, for innovative developments. One is the microwave boiler, currently being developed by British company Heat Wayv, due to be trialled by the end of this year.

Even more radical is Thermify’s HeatHub, a boiler operated not by gas or electrical currents but the heat arising from a bank of computer processors. In fact, the HeatHub is a boiler-sized cloud computing server with home heating as a by-product. The electricity costs are covered by the server’s users, enabling Thermify to charge a flat rate to the householder for as little as £50 a month, according to Thermify’s Dr Garry Felgate, who says the first HeatHubs should appear in the second half of 2022.

Then there’s Tepeo’s Zero Emission Boiler (ZEB). Essentially a new take on the storage heater, it’s programmed to use the cheapest electricity whenever available to heat a washing machine-sized ‘heat battery’. A patented highly insulated ultrahigh density core can retain heat at high temperatures for long enough to power a conventional pipework and radiator system whenever required, and, it’s claimed, for half the purchase price of a heat pump.

PV panels and batteries

Any form of electrical heating can benefit from power generated by photovoltaic panels. Saving the use of heavy demand items, such as washing machines, dishwashers, tumble dryers and immersion heaters for sunny days can make a dramatic difference to fuel bills.

Even more savings can be made by storing unused PV-generated electricity in household batteries like the Tesla Powerwall, which can also charge from low-cost overnight grid electricity. Currently, however, batteries are costly and less long-lived than the panels that charge them, making them best suited to households living off-grid.