Focusing on the conversion of existing properties to low carbon sources will be essential in meeting UK climate change targets, especially considering that 80% of the building stock that will exist in 2050 is already built. This report focusses on small and medium sized towns as they present more challenges than larger towns and cities, which have higher heat density and associated economies of scale. The full alternative heat solutions report can be read here.
The report explores possible technologies able to convert a UK town to low carbon heating and analyses the costs, practical constraints and challenges associated with each of them.
The technologies analysed include:
- Hydrogen with carbon capture and storage combined with electric cooking
- District heating (DH) from biomass and heat pumps
- Electric heat pumps (EHP) and electric cooking
- Hybrid heat pumps (HHP) with gas cooking
The analysis concludes that the lowest net present cost (NPC) for the solutions modelled is offered by hybrid heat pumps. The remaining technologies are, in order of increasing NPC: district heating, hydrogen and electric heat pumps.
The hydrogen solution offers the greatest CO2 reduction potential of 87% compared to the business as usual. Electric heat pumps, hybrid heat pumps and district heating options offer similar, lower savings.
The results illustrate that hybrid heat pumps offer the lowest lifecycle cost and the lowest cost of carbon emissions reduction. While this presents the most attractive economic solution it will retain gas supply and, hence will not achieve carbon neutrality. The main challenges to implementing any of the solutions considered will relate to lack of public acceptance, investment funding and regulatory mechanisms to proactively drive the uptake of solutions.
The report undertook a simplified analysis where the solutions were applied to 100% of properties. With hybrid heat pumps performing the best in low density areas, it is likely that a mix of solutions will be optimal as district heating appears attractive in areas of higher heat density.
Breakdown of cost for each of the technology options considered
In the study, the pilot town of Cowdenbeath was chosen. This town was selected due to its characteristics being closest to the national average for a small-medium sized UK town. The proximity of Cowdenbeath to the Mossmorran Ethylene Plant, which produces hydrogen as a by-product of its process, provides a unique opportunity to undertake a large-scale pilot to investigate the impact of hydrogen distribution within a town. The solution offers a benefit in terms of NPC compared to the main scenario. While not a low carbon solution, it has the potential to be converted after proving the concept through further investment in carbon capture and storage, or by connecting the town to a national hydrogen network if this concept progresses.
This example demonstrates the importance of considering the individual characteristics and opportunities of local natural resources and infrastructure because they will also influence the cost of heat production. The report also concludes that there is a requirement to standardise a methodology for strategic planning of energy solutions that reflects these differences.
Commenting on the research, Paul Steen head of Energy for Ramboll says: “The analysis and reporting clearly demonstrate the lifecycle benefit of retrofitting energy efficiency measures before undertaking low carbon solutions. This backs up UK and Scottish Government plans to address energy efficiency as a priority. The challenge is how to persuade property owners to invest in energy efficiency where the carbon and commercial paybacks are over long timescales.”