If you want to help stop the climate crisis, get smarter about heating your home

The climate column: We need to be far more efficient in how we heat our homes and the government must tell the truth that in a climate emergency, wasting heat threatens our children’s futures

With the record October Arctic ice-melt sending shivers of terror down the spines of climate scientists, it is clear that Extinction Rebellion are right that we need net zero carbon now, rather than 2050. 

One important area we should personally focus on this winter is getting our home heating to be zero carbon. 

The average UK home heating system emits 2.25 tons of CO2 per year. The independent Climate Change Committee says that the government’s plans, which cut home energy efficiency investment to a miniscule £0.9bn per year, are too limited to decarbonise the UK's 29 million buildings.  

We need to be far more efficient in how we heat our homes and install zero-carbon heating systems, which do not use any oil, gas or coal. The government must tell the truth that in a climate emergency, wasting heat threatens our children’s futures.  

We can no longer afford to waste carbon by heating our homes above 18C (or 21C for the elderly). With an extra jumper, I am comfortable at 16C in my home and office. Every 1C rise in temperature above 18C can add 10 per cent to the running and carbon costs of heating our homes.

It is time we also stopped heating empty rooms. Turn the heating down to frost protection in those we are not using and close the doors. Then set our central heating timers correctly. In a well-insulated home, it should only come on 30 minutes before we get up, go off about 30 minutes before we go to work and then off at least an hour before we go to bed.  

We are building at least one nuclear power station which will likely go towards heating empty rooms and offices. Ensuring that the loft is insulated, cavity walls filled and doors, windows, floors and unused chimneys are draught proofed is the minimum we need to be doing. These are cost effective, with short pay-back periods, often under three years.  

However, insulating the solid walls, single-glazed windows and wooden ground floors of our millions of cold Victorian homes will be expensive, with pay-back periods of up to 50 years or more.

The costs to retrofit a semi-detached Victorian home to modern warmth standards can vary from £12,000 to £54,000.   If you have a Victorian home and, like most of us, do not have a spare £30,000 to do a whole house energy efficiency retrofit, super insulate the room you live in most instead and change your family’s lifestyle to maximise use of this room.  

This is what I have successfully done for my home bedroom/office. For much of the winter it warms to about 16C, with just a 160-watt tube electric-heater. 

My solar panels usually produce enough to run this in winter and the insulation retains the warmth in the evenings when the sun goes down. If especially cold, I have a back-up 560-watt infrared panel heater.  

This approach might be a good use of the government’s six-month coronavirus “stimulus” £5,000 home energy grant scheme.  

Having made the fabric and usage of your home heating ultra-efficient, you then need to choose a form of net zero carbon heating for the remaining heat required.  

This is a complex decision. There are so many variables: type of house, number of occupants, commitment to climate action, cost, geographical location and access to renewable electricity.  

Alternatives to fossil fuels include electricity, wood, hydrogen and biogas. They all have advantages and disadvantages. It is sadly now clear that wood-fired systems are not ideal for urban areas due to air pollution, but have a role for some rural homes with local wood supplies.  

Tentative proposals to convert the natural gas network to renewably produced hydrogen are unlikely to be achieved quickly. It is more efficient anyway to deliver the renewable electricity directly to homes rather than convert it to hydrogen.  

Some energy companies are now supplying biogas for gas central heating customers on the national grid. However, there simply is not enough waste biomass to supply the entire national grid with biogas.  

Electric heating systems are an option but are only zero carbon if operated on a genuinely green tariff, such as that from Good Energy or Ecotricity or if somebody has their own renewable electricity installation.  

A simple option - and as with a number of these choices if you have the money available - would be to replace your gas boiler with a 100 per cent efficient electric boiler. But electric heating can be significantly more expensive to run than gas. An electric combi-boiler costs from about £1,800 and gas is about 4p and electricity 15p per kwh.  

Although, the government will be placing a climate change levy on gas from 2022.  

An air source heat pump for central heating and hot water for a semi-detached house costs about £9,000 upwards but the running costs if installed and sized correctly should be lower than gas or electric boilers.  

Then there are infrared panels, mentioned above, which are used in some churches, as they heat the building fabric and its users, rather than wastefully heating the large space above the congregation. Their running costs are about half that of a traditional electric convector or bar heater. 

The Carbon Trust was unaware of any comparative studies looking at the capital, carbon and running costs of the various electric heating options. But Will Rivers, their programmes and innovation manager, pointed out that the electric grid is usually at its most carbon intensive between 4.30pm and 7.30pm.  

He confirmed that without a significant increase in home energy efficiency the grid would not be able to provide the amount of green electricity needed to switch wholesale to electric heating.  

So, get cracking on with creating your own zero carbon home heating and keep pressing the government to take the urgent systemic actions necessary.  

Donnachadh McCarthy is an environmental auditor, campaigner and is the author of ‘The Prostitute State – How Britain’s Democracy was Hijacked’