MolCal will contribute to establishing a critical mass of researchers in promising exploratory topics on caloric materials and energy conversion technologies for solid-state cooling and heating applications at near-ambient and very-low temperatures. Temperature control systems are responsible for approximately half of the EU energy consumption expenditure. This figure alone amply justifies the need to dedicate great efforts to the search for alternative refrigeration and heat pump methods. Research on caloric materials has never been as active as it is now, due to the prospect of new-generation refrigerators and heat pumps that are energy efficient and environmentally friendly, on the one hand, and the policies on low-energy consumption and global warming refrigerants, on the other. MolCal presents an approach never tried before in similar collaborative research training programmes. We will consider caloric materials that fall under the umbrella of molecule-based materials and can respond to different sources of the driving stimulus, be it magnetic, electric, and/or mechanical. Since there is no clear-cut consensus on which type of caloric material holds the most promise, this multi-front approach will be an advantage because it will permit transfer of methods already developed from the magnetocaloric subfield into the others, which are increasingly in the spotlight because of their enormous potentiality. Furthermore, MolCal will develop devices based on low-cost barocaloric materials and, due to the molecular characteristics, will progress towards challenging applications by exploring the limits of the smallest size of magnetic refrigerators. Academic and non-academic leaders, from top research institutions in Europe and outside, will expose the doctoral researchers to integrative, multidisciplinary, and multisectoral training in chemistry, materials science, physics, device development, and relevant transversal skills.

Hydrofluorocarbons (HFCs) have become the de facto alternative to chloroflurocarbons (CFCs), since CFC phasing out in 1994, and are used primarily in heating, ventilation and air-conditioning equipment (HVAC). The US and EU now seek to phase-down HFC use due to their own toxicity issues and damaging environmental impact. In addition to these noble reasons, the refrigeration industry currently accounts for 17 % of the world's electricity consumption; any increase in efficiency would therefore be welcomed in both an economic and environmental sense. Finding alternatives to HFCs has created a major technological and scientific challenge. Ideally, any new technology should be made from sustainable sources and offer increased efficiencies and environmental credentials over current practices. Recently, there has been a strong focus on developing solid state materials which demonstrate caloric effects, where refrigeration is caused by an external field which induces a large isothermal entropy change and large adiabatic (isolated system) temperature changes. The external field can take the form of a magnetic field (magnetocaloric), electric field (electrocaloric) or hydrostatic pressure (barocaloric). While, magneto- and electrocaloric effects require large magnetic or electric fields, which are reliant on rare-earth elements for their generation, the same does not apply to the generation of pressure. Thus, in principle, applications based on the barocaloric (BC) effect will have less limitations for commercial realisation. The potential energy savings through the adoption of BCs over current refrigeration systems has been calculated to be 1260 terawatt-hours. The BC effect in materials is unlocked via the application of external pressure to the material. This causes a structural transformation which is coupled with an increase in temperature, much like a when you stretch an elastic rubber band causing it to heat up. This process of a solid-solid phase transition can be cycled like the established vapour-compression technology to work as a refrigerant. To date few materials have been found to have the BC effect, and those that do vary wildly by type, ranging from metal alloys, to polymers and plastic crystals. This means that although there are few published BC materials, they must be more widespread than first thought. The scope of this fellowship is to use a combined computational and experimental approach to search, understand and control the BC response of polymorphic materials. I have experience of combining both computational and experimental methods in materials chemistry and have found that this complementarity is essential in order to fully understand structural changes as well as the energetics of those changes. The project will extend our library of solid-state materials built from our new understanding of how to maximise BC effects. Specifically, I will design materials to be able to tune their working temperatures, as industry requires a wide range of temperature-controlled environments. The ultimate goal is to compile a portfolio of materials which have BC responses at different temperatures which can be explored for commercial application as refrigerants and coolants at fixed temperatures. These materials will be non-toxic, easy to dispose of and more efficient than the status-quo of today's technology. The development of solid-state BC materials as refrigerants will: (1) Reduce the greenhouse gases emissions associated with the refrigeration industry. (2) Create solid-state materials which can be disposed/recycled more easily than current technologies based on gases/liquids. (3) Improve efficiency of the heat transfer, reducing refrigeration energy demands. (4) Improve the knowledge of design principles for controlling materials properties via phase changes which is applicable to many areas including pharmaceuticals, heat batteries and thermo/piezochromic materials.

The UK's electricity networks are serving millions of people everyday but now are facing a challenging future, with ageing infrastructure but increasing penetration of Renewable Energy Sources (RESs). As such, the Office of Gas and Electricity Markets (Ofgem) has approved plans to spend £17bn for upgrading the UK's electricity networks till 2023 by using smarter technologies. As one of the most promising solutions, smart grid has attracted much attention, since it is capable of enabling bidirectional flows of energy and communications in the power grid infrastructure, that is crucial in improving the reliability, security, and efficiency of the electric systems and keeping the lights on at minimum cost to consumers. The proposed research is concerned with one key smart grid application, i.e., Virtual Power Plant (VPP) which is designed to aggregate the capacity of many diverse distributed energy resources (DERs) and flexible demands to create a single operating profile as one "virtual power plant" that helps balance supply and demand in real time. To facilitate VPP, both optimisation algorithms and communication technologies play a significant role, but the full potential of VPP has been hampered by the lack of joint power-communication system models and the thorough analysis of the impact of communication system imperfections to optimisation algorithms. If successful, this research will provide better understandings of these two systems operating with close interactions in VPP, develop more advanced methods in the design of VPP, and implement a hardware testbed of VPP with two-way real-time communication capability in Durham Smart Grid Laboratory. These could potentially lead to more efficient management of RESs and flexible demands, ultimately to improved operational efficiency of power grids for system operators and to reduced cost for consumers. Perhaps most importantly, however, is that this research will enable us to begin asking how we shall optimise the performance of smart grid technologies, considering not only power systems but also realistic communication systems, thus encouraging multidisciplinary research and cross-fertilising both fields.

The UK has set a target to reach net zero emissions by 2050. Heat accounts for nearly half of the UK's energy consumption. Among several possible solutions, heat pumps are considered as one of the most promising technologies for decarbonising the domestic heating sector. Among all heat pumps, air source heat pumps (ASHP) are the most cost-effective option for householders. the Committee on Climate Change (CCC) recommends mass deployment of heat pumps to comply with the net zero target, and their net zero 'Further Ambition' scenario includes the deployment of 19 million heat pumps in homes by 2050. However, the uptake of heat pumps in the UK is very low at present. In 2018, heat pump sales in the UK were around 27,000 units (most are ASHPs), significantly lower than other EU countries. This represents a grand challenge for the government, industry, business, and research communities. There are a number of technological and non-technological barriers hindering the wide uptake of heat pumps, particularly air source heat pumps in the UK. There is a mismatch between the current ASHP products and the existing infrastructure and property configuration. Over 80% of houses in the UK use gas boilers for space heating, so their heat emitters (i.e., radiators) are designed for high temperature heat supply using gas boilers. However, most ASHPs available in the market have a relatively low heat production temperature. Secondly, ASHPs are vulnerable to ambient conditions. Their heating capacity and coefficient of performance drop dramatically as the ambient air temperature falls. Furthermore, frost starts to build up at the surface of the outdoor unit when the air temperature drops to around 6 C, so the outdoor units have to be regularly defrosted. Non-technical barriers have also played an important role behind the low uptake of heat pumps. The current UK heat pump market suffers from high capital cost and a low awareness of the product. This project, based on the PI's pending patent (Application number: 2015531.3), aims to develop a novel flexible, multi-mode air source heat pump (ASHP). This offers energy-free defrosting and is capable of continuous heating during frosting, thus eliminating the backup heater that is required by current ASHPs. We will address the key technical and non-technical challenges through interdisciplinary innovations. Our project is also supported by leading industrial companies with substantial contributions (e.g. the compressor). The developed technology offers energy-free defrosting and can be operated at different modes to benefit from off-peak electricity and/or warm air during the daytime. It will be much more energy-efficient than the current products, and thus could facilitate rapid uptake of air source heat pumps, making an important contribution to the decarbonisation of the domestic heating sector in the UK.

This research project aims to tackle the barriers inhibiting the rapid introduction of large amounts of low-cost electrical and thermal solar energy generation by driving down the cost per kWh. To do this we will: * Develop enhanced optical concentrator systems which exhibit improved luminance uniformity over the photovoltaic cell; * Extend the lifetime of the PV cells to beyond 50 years by the use of active thermoelectric cooling; * Increase the energy conversion efficiency by linearising the PV cell electrical generation, controlling cell temperature and by implementing enhanced Maximum Power Point Tracking algorithms; * Integrate a thermal storage system with the PV / TE receiver. * Capture large amounts of thermal energy from the solar-> electrical conversion process and use this to enhance the efficiency of co-generation plant or displace fossil fuel combustion. The technology resulting from this 4 year research programme will be commercialised throughout the project life by a number of industrial partners and be equally suited to domestic use or to utility-scale power plants connected to the grid. Such installations will make a significant contribution to the UK meeting its 2020 CO2 reduction targets and help ameliorate the growing problems of energy insecurity and energy poverty.