For this month’s ‘In Focus’ we will be looking at heating, which holds the dubious distinction of being the UK’s biggest source of carbon emissions – it currently accounts for around 37% of the country’s carbon footprint, the largest contribution of any sector.
Around 90% of homes use natural gas boilers to keep warm, while many businesses and industries also generate large amounts of emissions from heat – the health, hospitality, emergency services and education sectors have a huge demand for hot water for cleaning and catering purposes, while industrial processes such as high-temperature blast furnaces for making iron and steel also use a vast amount of energy to generate heat.
The Department for Business, Energy and Industrial Strategy has said: “Heating is central to our lives. In our homes, we rely on it for comfort, cooking and washing. Businesses need heating and cooling for productive workplaces and heat is integral to many industrial processes. It is the biggest reason we consume energy in our society.”
There are several potential solutions to this, but as always, the route forwards is not straightforward. Greening the gas grid with hydrogen, adopting district heating networks and electrifying heat are all potential options, but no single available and affordable silver bullet seems to exist. This month we will explore the various solutions available and discover which parts of the economy can be cleaned up in a cost-effective and manageable way.
Greening gas refers to lowering the carbon content of the gas we use, typically by replacing it with biomethane or hydrogen – however, the process is not as straightforward as simply deciding to use a new fuel. Biomethane could be blended with conventional gas and added to the existing grid but it is not entirely clean, while converting to hydrogen would require huge upheaval and replacement of the existing network, as well as individual boilers in homes potentially having to be swapped over.
There are concerns regarding whether either option could deliver significantly lower emission gas affordably and within the given timeframes, as well as much debate as to whether such a large and intricate project could be rolled out safely and successfully to deliver benefits before the deadlines required.
Electrification is another popular option – despite electricity used for heating also having a carbon footprint, depending on how the power in question was generated, as the UK’s energy mix becomes increasingly renewable, this negative impact is falling – emissions from grid electricity have been nearly halved since the turn of the millennium as coal power stations continue to be closed down and new solar photovoltaics and wind farms are built.
The Energy Systems Catapult stresses there is no single solution that will be able to decarbonise the heat sector – it states: “Low carbon or carbon-neutral heating solutions already exist, however, a top-down “blanket” solution such as all-electric or all-hydrogen is projected to cost twice or three-and-a-half times as much respectively compared to a bottom-up approach that chooses the best low carbon heating solutions on a place by place basis.”
The difficult issue of decarbonising heat is worsened by the poor energy efficiency credentials of the UK’s building stock, which is generally of poor thermal efficiency – nearly 70% of households are thought to suffer from either damp, drafts, or overheating, wasting a significant proportion of the energy that is used and meaning emissions are being generated for no reason.
On the domestic level, 48% of the public have ‘no awareness’ of low carbon heating and the Energy Systems Catapult suggests “current incentives do not encourage many households to switch to low carbon heating”, and points out that only 2% of qualified gas engineers in the UK are specific low carbon heating engineers.
A similar problem exists on the industrial and business level, where energy managers are often confused by an array of possible options with little clear idea of which will bring their business the best returns on investment and decarbonisation results. For this reason, it is often difficult to pitch and justify significant heat investments to the board.
The government says: “We are now looking at the best ways to cut carbon emissions from heat during the 2020s, thinking about how we can reduce reliance on subsidy. We want to lower the barriers to the take-up of low carbon heating and cooling. We also want to sustain a viable supply chain for heat pumps beyond the Renewable Heat Incentive (RHI), while not closing off options for longer-term heat decarbonisation.
“There are a variety of technologies with potential to contribute to the transformation necessary to meet 2050 targets – including heat networks, heat pumps, hydrogen and biogas. It is not yet clear which combination of these will work best at scale and keep costs down. Different approaches need to be tested further as we develop a long-term plan that delivers the best solution for consumers.”
In the domestic sphere, the Committee on Climate Change (CCC) used its latest progress report on efforts to cut emissions to call for UK households to see a total phase-out of fossil-fuelled boilers by 2035, whilst certain businesses across the country were recently granted an extension to the non-domestic RHI deadline as a result of the coronavirus pandemic.
The government is currently developing a new policy framework for the long-term future of heat and working on a Heat Policy Roadmap to set out the key steps required to make these key decisions on heat decarbonisation in the 2020s, which it aims to publish later this year.