UK Heating and Building Strategy

The UK governments new long awaited Net Zero Carbon heating and building plan says that ‘ultimately, Net Zero will mean gradually, but completely, moving away from burning fossil fuels for heating. Which is why we are setting the ambition of phasing out the installation of new natural gas boilers from 2035.’ However, given the potential for backlashes against the scale and cost of what needs to be be done, and this high level commitment in particular, it wants to move slowly on choosing a replacement. So although the headline story is that it backs heat pumps, the strategy is relatively cautious and nuanced on that.  

It says that ‘the future is likely to see a mix of low-carbon technologies used for heating: electrification of heat for buildings using hydronic (air-to-water or ground-to-water) heat pumps, heat networks and potentially switching the natural gas in the grid to low-carbon hydrogen’. However, it goes on, ‘while there is work to be done to identify the best solutions for different buildings and regions, there are also areas where the solution is clear and we can take decisive, ‘no-regrets’ action now. No or low regrets’ means actions that are cost-effective now and will continue to prove beneficial in future. For example, installing energy efficiency measures reduce consumer bills now, while making buildings warmer and comfier, but have the added benefit of making future installations of low-carbon heating more cost-effective. For example, hydronic heat pumps will be a key technology for new buildings and buildings not connected to the gas grid, and heat networks will be a key technology in areas of high-density heat demand and where there are large low carbon heat sources’. 

So heat pumps, along with heat nets, get an early go-ahead: ‘Heat pumps and Heat Networks are proven scalable options for decarbonising heat and will play substantial roles in any Net Zero scenario, so we need to build the market for them now. A UK market with the capacity and capability to deploy at least 600,000 hydronic heat pump systems per year by 2028 can keep us on track to get to Net Zero and set us up for further growth if required. This means ramping up UK-based supply chain and deployment from approximately 35,000 heat pumps a year, to potentially being able to replace around 1.7 million fossil fuel boilers per year’. And the development of Heat Nets will also be accelerated- the strategy notes the CCC view that heat networks could supply 18% of UK heat by 2050. 

Upgraded energy efficiency is also backed strongly: ‘The journey to Net Zero buildings starts with better energy performance. Increased awareness of energy use and the need for greater efficiency is the first stepping-stone to enabling consumer decisions to improve building energy performance and use smarter, more efficient products and system’ 

That’s a welcome, if rather obvious, statement. Even more welcome is the commitment to dealing with the building envelope, rather than just cutting energy use in poorly designed buildings via clever add-on gadgets: ‘Improving energy efficiency by adopting a fabric-first approach is key in ensuring the transition to low carbon heating is cost-effective and resilient. ‘Fabric-first’ means focusing on installing measures that upgrade the building fabric (e.g. walls/lofts) itself before making changes to the heating system’. That will not always be easy- there can be energy, cost and performance trade offs between fabric efficiency and green energy generation in, on, or near buildings. But the government says ‘we are committed to supporting businesses and households to upgrade as many buildings as possible to higher levels of energy efficiency and flexibility, in a way that will ensure long-term compatibility with low-carbon heating systems’, with all of this to be done in a ‘co-ordinated system-wide approach’. Well let’s hope it succeeds! Its previous energy efficiency in housing effort didn’t- it was a major flop. 

Given the risk of making big messes in the area, the government is clearly loath to rush into making too much of a commitment to hydrogen for heating.  It’s certainly not yet clear what the best mix will be, with some favouring green hydrogen rather than heat pumps, but with hydrogen having a range of issues, including safety and cost. So the government says ‘we will take major strategic decisions on the role of Hydrogen for heat by 2026’. Meantime there will be some local trials, demonstrations and more research on hydrogen and associated systems.  But for the moment the emphasis will be on heat pumps, with support being provided to consumers who switch early, with £5,000 Boiler Upgrade Scheme grants, and then the aim being to reduce the costs of heat pumps by at least 25-50% by 2025 and move towards parity with (gas) boilers by 2030. So ‘alongside action to remove distortions in energy prices, heat pumps should be no more expensive to buy and run than existing boilers and we are investing in innovation to make them smaller, easier to install & beautiful in design’.

That approach though is not entirely risk free. Although they can be highly efficient, and low-costs compared to hydrogen heating are claimed, heat pumps wont always work well in all situations, with performance usually being worse in winter. To get reasonable overall heating efficiency the building also has to have improved insulation- adding to the already high cost and difficulty of installation.  There are then issues of maintenance to ensure that these relatively complex systems perform optimally.  The Net Zero Heating Plan however is fairly sanguine, at least about the problems of installation. It notes that heat pump installation ‘must be compliant with Part L and Part P of the Building Regulations. These regulations. relate to energy performance of buildings and electrical safety respectively, and installers have a duty to ensure compliance. Existing heating engineers can be upskilled to install heat pumps in one week or less’.  

In terms of subsequent operation, an issue possibly for the next stage of the programme is whether hybrid electric heat pump gas/hydrogen boilers would be viable. Using gas could help reduce demand for heat pump power at peak heating times, and BEIS has identified some quite large system cost advantages, although it does involve supply system duplication- power and gas. The Heating plan says more work is needed: ‘Based on the current evidence, we acknowledge that hybrids could play a transitional role in the 2020s and 2030s, but it is too early to determine the Net Zero energy system composition and whether to rule hybrid systems in or out of the 2050 energy mix’. 

So it is a bit timid on hydrogen and hybrid innovations, and there is not much on biogas heating, or solar heating/heat store systems, options which could arguably be helpful in some contexts, as has been shown, for example, in Denmark. But for a relatively cautious British report, it’s not too bad.  Although, despite its claims about hoped for improvements in the affordability of heat pumps, it may not convince the various ‘Save our Boilers’ campaigners, including Ecotricity, who want to use green gas made from grass! And also (from a very different perspective) the Global Warming Policy Forum, now revamped as Net Zero Watch, which, along with others, is backing a national referendum on the whole Net Zero policy. If that happens it could open up a big debate and not just about heating.  

*Going back in time to the pioneering Milton Keynes eco-houses, have we learnt much since then?  A survey of resident experiences at the time identified all sorts of issues.