Feasibility study to assess the potential for retrofit, energy efficient, district heating/cooling and electricity generation in the City of Durham, UK
Durham County Council has corporate priorities to reduce carbon dioxide emissions by 40% by 2020 and 55% by 2030. District energy is one technology recognised by the EU and UK governments with great potential to deliver carbon emission savings, encouraging economic development whilst also potentially generating income. The UK Government established the Heat Networks Delivery Unit (HNDU) to encourage the adoption of district heating schemes in England and Wales. This study was funded by HNDU, the aim being to identify opportunities for development of retrofit district energy networks in Durham City and bring the best opportunities forward to business case development. The energy sources considered comprise a combination of heat pumps, biomass and gas combined heat and power.
Phase 1 scoped the potential for district heating/cooling and private wire (electricity supply) across the city and focused upon key ‘Heat Clusters’ where technically viable and potentially financially attractive development opportunities could exist. The most promising clusters were included in Phase 2 of the study, which included detailed technical feasibility and financial modelling including Capital and Revenue, Energy Sales, Tariffs etc of the preferred opportunities. A key element of Phase 2 was engagement with internal and external stakeholders. This included a range of workshops and meetings, in order increase understanding and to further establish opportunities, key issues and constraints
The feasibility study cost €87,888 Capex for Durham City clusters is calculated at €11.15M and €22.11M would be the cost of providing a heat network for the Durham University Cluster
Evidence of success
Phase 1 resulted in a masterplan for district energy in Durham City that identified specific clusters as having potential for development of district energy networks in the near term. Results were sufficiently encouraging to warrant Phase 2 which delivered a detailed financial assessment and developed a business case that provides the Council with information as to how best to develop the favourable clusters. Stakeholder engagement and associated economies of scale being key to project success
The study uncovered geographical constraints specific to heat networks in urban areas, such as competition with existing infrastructure. The complexities of retrofit to existing buildings were also recognised. Partnership working led to a fruitful relationship between the Council and the University.
Potential for learning or transfer
The methodology and approach to Phase 1 and 2 demonstrated learning opportunities by rigorously evaluating by several energy options including some bespoke to Durham City (e.g. river source heat pumps). The evaluation of options included a range of existing and historic buildings within different ownership for retrofit heat networks. Sustainable heat provision and retrofit of heat networks in urban areas presents a huge challenge/opportunity for most regions. Therefore, the study methodologies are highly transferable. Additionally, the project delivers good practice by exploring different Business Delivery Models such as Energy Service Company (ESCo) formation and Community Ownership models. The way in which this project has engaged with stakeholders and other delivery partners builds a strong basis for future development throughout the planning, construction, implementation phases of such a project and highlights economies of scale that can be achieved through partnership working.