David Holmes is the founder of the Boiler Guide.
Whether it’s installed in the kitchen, garage, bedroom or even in the garden, the vast majority of UK homes rely on a boiler for hot water and central heating. These boilers are fuelled by natural gas, or oil in some cases, both of which are fossil fuels. In addition, the homes with electric heating systems are likely to be using electricity which has been generated through the burning of fossil fuels.
When fossil fuels burn they emit carbon, a greenhouse gas, into the atmosphere. Greenhouse gases (and other pollutants) cannot escape the atmosphere. They hang around absorbing trapping heat which is causing the temperature of the earth’s surface, oceans and atmosphere to rise. This is called the greenhouse effect or global warming and has led to the climate change crisis we face today.
This is why the UK is one of many countries working towards net-zero carbon emissions by 2050 and, as the heating industry is responsible for around a third of all UK carbon emissions, why we have to change the way we heat our homes.
What’s the plan?
Unfortunately, we don’t know. The Committee on Climate Change (CCC) is the independent advisory body which is guiding the government towards alternative heating systems which use renewable sources of energy and will not emit carbon into the atmosphere. The government has already acted on their advice by making it illegal to install gas boilers in new build homes from 2025, but further than that we have no plan in place.
If we do not make changes in the next decade, we are likely to run out of time to halt the consequences of climate change. This is why the CCC, environmental experts and the heating industry are urging the government to commit to a plan in the Carbon Budget of September 2020. This will outline how we will de-carbonise our society, the predicted costs and the requirements of industry.
How are we likely to be heating our homes in the future?
There are several renewable heating systems available, each with its own merits and drawbacks, but there will not be a blanket solution because the UK’s housing stock is so varied.
The most likely alternative for new builds appears to be low carbon, electric heating such as air source and ground source heat pumps which extract latent heat from either the air or ground outside the home. To work efficiently and effectively, heat pumps require a high level of insulation which is why they are more suited to newly built homes.
The biggest challenge we face is how to heat the 80% of UK homes currently relying on the gas grid. Asking homeowners and the industry to remove millions of gas boilers and replace them with an unfamiliar technology will be hugely costly and disruptive.
Instead, the heating industry has been researching and trialling the possibility of replacing not the boiler, but the fuel it uses. Specifically, we would keep the existing infrastructure of our gas network in place, but gradually change the fuel from natural gas to hydrogen gas. Unlike natural gas, hydrogen does not release carbon when burned. The snag is that producing hydrogen is costly and emits carbon, so a carbon capture and storage system will also have to be developed.
Hydrogen trials are already in progress such as HyDeploy in the village of Keele where the gas being supplied properties is made up of 20% hydrogen and 80% natural gas. Boiler manufacturers are also revealing prototypes of ‘hydrogen ready’ boilers which could be installed in homes from 2025. They would run on natural gas or a blend of the two gases until supplies of hydrogen are sufficient to enable a change to 100% hydrogen.
Homes which are not connected to the gas grid are likely to move to an electric heating system powered by electricity generated via wind turbines or solar PV panels. Alternatively, off-grid homes may be able to use a combination of renewable heating technologies such as a biomass boiler or heat pump for heating with solar thermal panels for domestic hot water production.
In all cases higher levels of insulation will be required alongside smarter heating controls and more accountability (from individuals and organisations) to improve our energy efficiency levels. While we are unlikely to see significant practical changes in the way we heat homes over the next decade, the next few years need to represent a watershed in both our living habits and government policy.
For more information about Boiler Guide, visit www.boilerguide.co.uk