DECC Funds Solar Powered District Heating Demonstration
CHOICES Consortium wins DECC Heat Network Innovation contract
Clean Energy Prospector, Eunomia, ICAX and the University of Bath have been awarded feasibility assessment funding from DECC. The consortium’s CHOICES project will demonstrate a small-scale, modular heat and power Energy Centre in Easton, Bristol, using surplus solar PV in summer to charge an interseasonal borehole thermal energy store using air source heat pumps.
The CHOICES Energy Centre will:
- shift electric consumption from times of peak winter demand to times of surplus summer solar generation
- exploit Borehole Thermal Energy Storage to store heat from summer to winter
- package existing commercially ready technologies in a novel use combination
- and have the potential to scale up rapidly.
The £7m fund was announced by DECC in October 2014 to stimulate innovation in heat network technology that can help to reduce carbon emissions, reduce costs and support the development of UK heat network supply chains. CHOICES was among 17 successful bids selected from 56 received by DECC in Phase 1 of the Small Business Research Initiative funding.
The problem to be answered is how to decarbonise heat – currently 80% of UK buildings are heated by gas. One approach is to use CHP (combined heat and power), but when fueled by gas the carbon reduction potential is limited to around 30% and the long term supply issues remain unsolved. When fueled with biomass then CHP is associated with supply chain complexity, high operational costs and environmental impact from transport and smoke emissions.
CHOICES: Community Heat Optimisation with Intelligent Control of Energy Storage
The aim of the CHOICES project is to demonstrate decarbonisation of heating by employing an innovative solar district heating network with seasonal thermal storage in the heart of a suburban neighbourhood. The project combines pioneering interseasonal heat storage technology from ICAX, energy-vector research from the University of Bath, CEPRO’s experience in energy metering, monitoring, engagement and billing at the local community level and full life cycle assessment by energy consultancy, Eunomia. The team is working closely with Easton Community Centre and Easton Energy Group at the Owen Square site in Bristol.
Damon Rand, Managing Director of Clean Energy Prospector, says "We are delighted that the CHOICES concept, a simple yet innovative combination of renewable technologies, has the won this contract from DECC. The project will show how much more can be done with solar at the local level, giving people and organisations true choice over how and when they heat their homes and buildings and how they can optimise energy use. There are thousands of similar sites across the UK and projects like this could make the country less reliant on gas in the long run and allow communities to manage their own heating networks."
Solar Heat Network
CHOICES Phase 2 project will demonstrate heat networks on site. A further report capturing evidence on the performance of the technology, lessons learned and next steps will to be provided at the conclusion.
The CHOICES project will integrate a number of renewable technologies with a control system that makes choices between alternative sources of heat generation, storage and supply. These choices will depend on the energy options available at different times of day and different seasons of the year and the heat demand from different buildings at different times.
The CHOICES proposal exploits commercially ready technologies in a novel combination and integrates them with a low temperature heat network. In particular, the use of excess summertime PV electricity to power an air source heat pump to transfer heat to the thermal store for recovery in winter provides for multiple system efficiencies: PV output is optimised. Heat pump efficiencies are optimised (by charging the borehole field with heat in summer). Air source heat pumps run on green electricity which may otherwise cause power quality issues on the local feeder or even reverse flows onto the Medium Voltage network.
Life Cycle Analysis
A full Life Cycle Analysis has been conducted by Eunomia in Phase 1 to quantify the cost and benefits of the CHOICES implementation at Owen Square. The CHOICES Energy Centre is expected to achieve energy savings of up to 64% and annual carbon savings of 38%, increasing to 51% carbon savings against gas by year 10 and 66% by year 20.
CHOICES is adopting a commercially driven, customer focused approach to the delivery of decarbonised heat. The focus of the technology development is to make metered heat financially attractive while facilitating ease of adoption and minimising disruption to customers.