In the UK, heating and hot water for buildings make up 40% of energy use and 20% of greenhouse gas emissions. These emissions must be reduced by over 20% by 2030, with a nearly complete decarbonisation by 2050, as part of the legally binding targets set by the Parliament in the Climate Change Act. To reach these targets and reduce the energy consumption, an innovative Versatile PCM (phase change material) energy storage system is presented.
The proposed Versatile PCM system can play an essential role in synchronizing end use energy demand and supply on a short to long term basis. Versatile PCM will encourage the use of energy-efficient solutions, especially being adaptable to the British weather where the solar radiation may change dramatically during a day. Versatile PCM is a promising advanced technology in addressing the "heating on demand" energy issue in building applications. Apart from a possible modest loss of sensible heat just after charging, the thermal energy will be effectively stored at room temperature or ambient temperature, without loss, until required. When heat is required, a trigger is activated to induce heat release.
Versatile PCM is an innovative and alternative energy storage measure with the advantage of controllable heat release and greatly reduced heat loss. To enhance long term energy storage at ambient temperature, installation can be placed as PCM groups, each with its own trigger, enabling release of heat only as demanded for long term needs. Normally, PCM can store heat with very high energy density, however, for long-term storage, heat loss is still a challenging problem. In conventional PCM storage, the PCMs are stored at ambient, above their melting point, resulting in continuous loss of energy. A major advantage of Versatile PCM is the use of the supercooling characteristics of PCM where heat is released only when the user triggers the crystallization mechanism, allowing long term, efficient storage.
Photovoltaics/thermal solar collectors will supply a hot fluid to charge the PCM cells. The heat can be supplied to cells directly by the collectors in high solar radiation days and by the heat pump in low solar radiation days where the temperature of the heat transfer fluid can be boosted by a PV-driven heat pump. The system can also be implemented in industrial applications, where waste heat can be stored in the PCM cells and used later when it is required. Different numbers and sizes of PCM cells can be activated at different times to meet the heating demand. The flexibility in amount of heat release and available time of storage makes the Versatile PCM installation unique and especially suited to regions with high variability in weather conditions such as the UK. The system can be charged during high solar radiation days and the stored heat released according to heat demand on subsequent days.
The novel technology developed through this project is much more efficient than traditional heating technologies by eliminating heat loss during thermal storage and being controllable in end use energy management, and therefore can significantly reduce the carbon emissions from the heating sector in the UK, if widely installed.

Potential Impact:
The impact arising from the project is likely to have significant benefits in the following areas: industries, nation, researchers and their institutions. This is specifically described as below.
Government: This project will contribute significantly to the UK's decarbonization of housing and building stock and developing of low carbon energy systems, thus to meeting the UK obligations to reduce greenhouse gas emissions. The outcomes of the project will provide a low cost, long life, efficient systems applicable to many areas, greatly reducing carbon emissions. It will also contribute to the growth in the nations' industry, accessing the UK's building and energy technology market, thus creating employment opportunities and improving its strategic role in UK economy. The widespread application of the proposed novel system can contribute significantly to the UK Government's target for progressively reducing carbon emissions.
Industry: The project will create manufacturing opportunities for the production of new sustainable, energy efficient, building technologies. As the proposed system is well suited for many climates especially those with varying weather conditions, production of PCM cells will create very large worldwide markets for the UK.
Society: The project will demonstrate to house builders and local authorities the potential for reducing buildings' energy consumption and carbon emissions. Such improvements would benefit future occupants by reducing their heating costs and thus improving their standard of living. The work will also help more broadly in enhancing public awareness and trust in the feasibility of properly developed sustainable heating technologies.
Project consortium: The fundamental research established during the project will be progressed towards exploitation via the effective actions of the industrial and governmental organisations involved in the project, directly supported by the academic organisations. Findings and social-technical reports will be generated and fully assessed by the supporting companies (PCM Ltd, Solar Ready Ltd., Free Running Buildings Ltd) and the UK academic institutions (University of Nottingham, University of Strathclyde and University of Reading). These parties will contribute to the reports that will then be published to enable other interested stakeholders to understand the benefits of the approach. These reports will also be communicated through the relevant national standardisation bodies for consideration of conversion into the national legal documents. Academic institutions will be the prime recipient of the project results and experience learned. The academic participants will benefit in terms of improved research profile and exposure to the commercialisation atmosphere. The successful implementation of the project is expected to create manufacturing opportunities for the manufacturers of heat exchangers, heat pumps, solar collectors and environmental engineering companies.