Warm homes - warm world?

Air source heat pump

The colder weather is gradually making its presence felt, with heating systems needed to keep our homes warm. Unfortunately, they also help to keep our planet warm as well.

Heating accounts for over a third of carbon dioxide (CO2) emissions in the UK, because it relies predominantly on the burning of fossil fuels, such as oil and gas.

There are greener alternatives, like biomass boilers and heat pumps but these have until recently been expensive to install. However, in 2014 the government introduced the Domestic Renewable Heat Initiative (RHI), a financial incentive to encourage people to replace their fossil fuel systems with those using renewable resources.

In an urban environment like Harrogate or Ripon air source heat pumps are the way forward. They are a proven technology used extensively in much colder climates such as Sweden and require no fuel storage (unlike biomass boilers).

Heat pumps use an electrically driven fan and compressor to take low temperature heat from the air and raise the temperature, through compression, to heat up water for radiators, underfloor heating and domestic hot water in cylinders.

For every kW of electricity used to run the heat pump over three kWs of heat is produced on average, making them far cheaper to run than oil, direct electric and LPG, and even natural gas when combined with some solar input. Because they use electricity, which is gradually being generated more renewably, the carbon footprint of a heat pump is a fraction of that of fossil fuels.

The RHI is paid to consumers quarterly for seven years and is intended to bridge the cost difference between a heat pump (typically £10,000) and a fossil fuel boiler. Depending on the fuel it is replacing, the payback period of a heat pump, with combined income from the RHI and fuel savings, is between four and eight years. CO2 savings for the average house after the installation of a heat pump is nearly five tonnes a year.

We also shouldn’t forget solar panels. The ending of the ‘feed-in tariff’ earlier this year might have sent a message that solar is no longer economically viable but in fact the cost of solar installations has fallen dramatically in the last eight years and the efficiency of solar cells has increased by 50%. That means that a typical installation cost is now only £4-5,000, with a payback period of 8-12 years, and will reduce CO2 emissions by around 750kg a year per household. Moreover, by the 1st of January 2020 all energy suppliers must pay their customers for any electricity they export under the Smart Energy Guarantee scheme.

Existing homes are one thing but what about all the new builds that we are seeing across the Har