The end of gas boilers: Problems and solutions

Gas is a fossil fuel

Gas used to be “greener” than other fuels, and it is currently around five times cheaper than electricity, thus, it has been the preferred heating option of choice for decades, and it is no surprise that around 85% of us currently have gas central heating in our homes. The government’s zero carbon policy is, however, a game changer and any fossil-based fuels will have to go. Decarbonising gas is not simple, and so the new government zero carbon heat strategy proposes a fundamental change in the technology that we use to heat our homes: phasing out new gas boilers by 2035.

Heating homes is a problem for zero carbon targets

Heating homes is roughly responsible for 15% of the UK’s greenhouse gas emissions and is a unique challenge for a zero carbon policy. Traditionally, insulating homes to reduce heat demand has been viewed as the most effective way to reduce carbon emissions from homes, however, currently only around 1% of homes are A-rated for their energy efficiency and “zero carbon” is fundamentally a different beast to “low carbon”. Successive governments, and a series of different policies, have failed to make serious progress on retrofitting homes, due to the cost and complexity of the challenge, but also perhaps due to the unique relationship we have with our homes and how much the government are willing to interfere. An alternative solution, that instead removes carbon from the fuel before we use it, has therefore been proposed in the recent government zero carbon heating strategy.

Is there such a thing as zero carbon gas?

The Government strategy opened the door to zero carbon heating options, two of which may be biogas, and hydrogen. Little detail was provided and perhaps this raised more questions with householders than answers. Put simply it is possible to mix gas made from organic material, rather than fossil fuel, into the existing gas grid to reduce its carbon density. This already happens for example, with biofuels already now being mixed into fuel pumps at the petrol station. However, the amount of biogas we could make or which the grid could accept is only a fraction of that which we need, and so its contribution to a transition to a low carbon economy it is useful, but it may never be able to provide a zero carbon fuel for us all in our homes. 

What is hydrogen?

The second gas option, hydrogen gas, could use the same gas pipes in the ground we have now, though it cannot be mixed with our existing natural gas. This is a major problem, since it means entire streets and neighbourhoods would need their gas to be turned off for a time, while their pipes are connected to a hydrogen supply instead. This is a huge logistical challenge and the infrastructure needed for hydrogen switching and means the costs of doing so would be in the order of many tens of billions of pounds. Householders would also need their gas appliances switching or adapting to work on hydrogen and this too is difficult, costly and inconvenient.

Electrifying heat is an opportunity

Progress on decarbonising the electricity grid, by increasing the amount of renewable generation (mainly wind farms, nuclear power stations and solar farms), has been relatively successful, to the extent that electrifying heat could be a silver bullet to decarbonising heat. The idea that households may be able to be switched over to zero carbon electric heating solutions, is something the recent government strategy is encouraging in their new strategy. 

Fuel poverty vs zero carbon

Direct electric heating (panel radiators, storage heaters, fan heaters etc.) uses 1 unit of electricity for every 1 unit of heat it provides, thus, a problem with this plan is that electricity is currently 5 times the price of gas. Switching to direct electric heating would therefore drive millions of households into fuel poverty. It is hoped, however, that a more efficient technology may provide a solution to this problem; electric heating provided via an air source heat pumps (ASHP), uses 1 unit of electricity for every 2 to 4 units of heat they produce. Although it is likely that this would still increase heating bills compared to gas, it may be more acceptable for householders, and may be cheaper than heating homes with oil or direct electric heating. The new government strategy, that is pursuing an electrification of heat, is light on details around this financial problem for householders, though indicates that the “green levy” we all pay on top of our electricity bills would be relocated elsewhere in the tax system. Heat pumps are can be more than 5 times the price of gas boilers and Government are hoping these prices will be cut in half by new innovation tom make them more affordable. Thus, Government is gambling on the price of electricity falling in the future to make this strategy viable.

Winning over the public

Convincing the public to switch will be a challenge, however. A recent report from Ofgem, who regulate the power industry, identified that only 14% of households would be happy to lose their gas boiler. Thus, there is a hearts and minds battle to win, that the government strategy has not provided any details on, which may be essential for the strategy to succeed and on which much more research is needed.

Read Dr Glew’s blog on the viability of switching to electric heating and his evaluation of the government’s strategy here.