Decarbonising heat is one of the toughest challenges faced  in tackling the urgent  climate emergency, says Ian Allan, Head of Market Strategy for heat networks

11,000 global scientists have recently declared that humanity faces "untold suffering due to the climate crisis". This echoes many other warnings, including a report by the Committee on Climate Change (CCC), which has set out recommendations for decarbonising domestic heat.

The UK has made massive progress in delivering a cleaner power network, but we are only starting on the journey to eliminating greenhouse gas emissions from heating. 

Lowering carbon emissions from domestic heating is critical to delivering on the UK's net-zero commitment. According to the CCC, energy use in homes, chiefly from heating and hot water production, contributes around 14% of the UK's greenhouse gas emissions.

The UK is one of the few European countries to rely on fossil fuel gas as the main source of heating. It is proposed that no new gas boilers will be fitted in new homes from 2025, but this will not be enough and we may have to replace all gas boilers to meet the 2050 targets. To put this into context, the Netherlands, one of the only other gas-reliant European countries, banned new gas boilers in 2012 and is now replacing existing gas boilers.

The question, of course, is what is the alternative to gas? The answer is that it is likely that a combination of technologies will be used, such as:

• Heat networks – where there is a dense heat requirement, such as cities and opportunities to take advantage or waste heat and other local heat sources.
• Heat pumps, either in heat networks or on an individual basis where there is a less dense heat demand. 
• Hydrogen or bio methane may be used in some areas, pumped through the existing gas mains, however this is a very immature technology and there are still lots of unknowns.

One of the key priorities is to address the huge heat waste from industrial and commercial processes (including electricity generation), The UK currently wastes more heat than it needs to satisfy its entire demand. If this waste heat, can be captured and used locally where it is needed, then fossil fuel emissions can be greatly reduced. Heat networks provide an effective solution by using heat productively close to the point of generation.  

One of the key issues is that for these solutions to work effectively and economically, all the buildings in an area should use the same solution, which is especially true of heat networks.

The Scottish Government is making significant strides in its zero carbon policy and Local Heat & Energy Efficiency Strategies (LHEES). This includes a zoning policy that allows Local Authorities to demand that buildings connect to a heat network both to export their own surplus heat or to consume heat from the network. This could be replicated across the wider UK.

The UK government is backing the expansion of heat networks, which are a key element of its proposed Future Homes Standard. The aim is to ensure that future new builds will have 75 to 80% less carbon emissions than those built to current energy efficiency standards.

The proposals take into consideration recommendations by the CCC that "new homes should not be connected to the gas grid from 2025". Instead, the government identifies that heat networks, heat pumps, hydrogen and biogas are some of the key low carbon solutions required to radically improve emissions performance of domestic heating. 

One of the barriers to weaning the UK heating system away from natural gas is the economics of cheaper gas prices relative to electricity, which is used for heat pumps. Gas incurs little carbon tax, with electricity shouldering the major taxation burden of decarbonising the grid. This disparity will slow the transition to cleaner heating methods.

Switch2 Energy supplies 70,000 residents and 180 clients across 500 heat networks. Its end-to-end service includes equipment design, manufacture and supply, metering, billing and pay-as-you-go, through to maintenance, energy centre management and customer services.