Heat pumps: What are the alternatives to gas boilers?

·4 min read
Engineer inspecting a boiler
Engineer inspecting a boiler

With soaring gas prices, some people are looking into alternatives for staying warm in the home.

It fits with government policy that no new gas boilers should be sold from 2025 in order to meet environmental goals for the middle of the century.

What's wrong with my gas boiler?

Right now, thanks to global gas markets and a lack of gas storage in the UK, your gas boiler is costing you a small fortune. It's also contributing to the emissions that are over-heating the planet.

If your boiler is nearing the end of its life, you may be considering replacing it.

But what else would keep you warm without heating the planet?

Heat pumps

Climate advisers anticipate that most homes in future will be warmed by heat pumps.

These devices extract warmth from the air or the ground, or from water - a bit like a fridge operating in reverse.

They are on the market already but they are costly - between £6,000 and £18,000, depending on the sort you install and the size of your home.

Heat pumps are subsidised under a scheme called the Domestic Renewable Heat Incentive. People receive payments for seven years based on the amount of renewable heat made by their heating systems.

However, MPs have called for better incentives to have heat pumps fitted.

What are the drawbacks?

Depending on the type of technology used, installation can be a lot of hassle - involving fitting bigger radiators and sometimes digging into floors.

What's more, heat pumps need high levels of insulation which aren't always possible on older solid-walled homes that populate many of the UK's cities.

The recent Green Homes Grant was supposed to help get heat pumps established. But it failed and was scrapped after six months, to the dismay of MPs who want a multi-decade scheme to help people heat their homes cleanly.

The government has promised to produce a new incentive scheme before November.

Even with the grants it's not clear yet whether the new scheme will make heat pumps cheaper to run than gas boilers.

One thing is certain though - the bills will be much more predictable and you won't have a spike in price like the one that's currently troubling people.

District heating

Another technology that may be available in some areas is district heating.

The energy giant Vattenfall is planning a network of hot water pipes in south-east London that could benefit up to half a million homes, businesses, and public buildings.

The heat will be produced from burning waste, which is controversial. In other places it may come from heat pumps sunk into rivers and the sea, bringing shared warmth to communities.

Again, bills should be more predictable and stable.

In a very few places heat might come from burning wood or fuel crops, where these are readily available in the right quantities.

Burning wood in home-log burners may be a delight, but it will be frowned upon, particularly in cities, where the fine smoke particles get deep into people's lungs.

What about hydrogen?

Big gas companies are keen on hydrogen, because it could continue to flow through their pipes to many homes.

The government is pioneering trials of hydrogen heating, with a series of pilots before the end of the decade,

But there are huge challenges.

Of the two methods of producing hydrogen, blue hydrogen creates greenhouse gas emissions during its production, so it also relies on capturing and storing those gases securely. The technology to do that won't be rolled out quickly enough to make a difference this decade.

Meanwhile, green hydrogen is manufactured using electricity, which can be carbon-neutral, but the process is currently far too expensive for the scale we need.

So while it will play a vital part in industries such as chemicals, steel and cement, hydrogen is unlikely to be produced in sufficient quantity to be heating many people's homes.

What other options are being considered?

  • Some places, such as Cornwall, will be able to use geothermal energy - from hot underground rocks. There's already a geothermally heated swimming pool in Penzance, for instance. But such opportunities nationwide will be scarce.

  • The agency that looks after decommissioned coal mines is pushing the idea that warm water could be drawn from old mine shafts to help with home heating.

  • The nuclear industry has also recently got into the act, arguing that surplus heat from nuclear stations could prove useful.

  • Heat batteries - like giant high-tech storage heaters - will play a part, along with infrared indoor heat panels, some of which are already used in some pub gardens.

Hopefully the big picture should be more clear in a couple of months.

Follow Roger on Twitter @rharrabin

Our goal is to create a safe and engaging place for users to connect over interests and passions. In order to improve our community experience, we are temporarily suspending article commenting