The project will provide the UK's first 'map' of network capacity and headroom and consider case studies in different parts of the UK in detail. It will also assess how heat and cooling demand might change in future using weather data. Based on all this the project will evaluate the nature of potential disruption in local communities created by heat system decarbonisation. It will engage with citizens to investigate their perceptions and expectations of heat system change. There are significant information gaps associated with the capacity of local energy distribution networks (gas, electricity and heat) to deliver energy for low carbon heating and cooling. Competing options include converting the gas grid to hydrogen, expanding electrification using heat pumps, and district heating. A key consideration is the nature of any constraints on the capacity of local networks, in particular the ability to deliver energy needed to meet peak demands, which can be far higher than average during extreme cold spells and perhaps in future during heat waves. Lack of both data and understanding of what disruption might be associated with heat system change are serious impediments to policy action on heat system decarbonisation. Research commissioned by the Committee on Climate Change analysis of a net zero target for 2050 concludes that utilisation of distribution network capacity is poorly understood. The project sets out to overcome this gap in information by evaluating what is known about distribution network condition based upon information reported by network companies and through interviews and surveys involving industry participants. It will compare electricity and gas networks and also consider district heating. Consumer acceptability of system change and local level disruption is also central to low carbon heat, yet it is similarly poorly understood and seldom linked to engineering detail at street or neighbourhood level. The project will use deliberative social science research to explore the expectations of citizens to the changes and disruption to local environments that might be associated with competing alternatives for delivering low carbon heating (and cooling) services to homes and businesses. Recent work on heat decarbonisation is strong with respect to assessment of end use technology options (i.e. what goes into the buildings) and on supply energy vectors (which energy source is utilised). However, it is weak on engineering, economic and social assessment of infrastructure needs and trade-offs - particularly for the 'last mile' or distribution network infrastructures that bring energy services to homes and businesses. This project is explicitly focused on this 'last mile' of infrastructure and combines engineering evaluation and constraint modelling with social science insights from public engagement with proposed heating solutions and their associated disruption(s), to assess the impacts of heat system change and what people think about them.

The need for sustainable energy sources to tackle climate change, as well as provide energy independence, has seen photovoltaic (PV) systems grow at pace, reaching terawatt scale in 2022. Likewise, the UK government aims to increase PV installations 5-fold by 2030. To achieve this, the UK industry needs to align with growing trends in the global PV market, which include shifting from monofacial to bifacial modules (which utilise light exposure on both front and rear), and from fixed-tilt to sun tracking systems (which follow the sun-path throughout the day). Currently, both these growing technologies, which have significant potential for additional uplift in energy yield are not well understood in high latitude and overcast climates such as the UK. This gap in research leads to increased risk for investors and can bottleneck the growth of the PV sector. This proposal aims to narrow this gap, by developing a state-of-art outdoor testing lab for PV systems, which can accurately measure bifacial performance under sun-tracking, validate energy yield models through experimental data, and then identify systems which produce the lowest levelized cost of electricity under UK climates. Furthermore, combining the advances of bifacial and sun-tracking will help integrate solar energy for dual-land use. This is critical, as the mounting global population (and therefore land scarcity) needs to sustain not only an increase in clean energy sources, but a growing food-water-energy nexus. Two key challenges for the PV industry are lack of standards for measuring bifacial technologies, as well as lack of validation for the modelling techniques. In both cases, this is primarily concerning the irradiance on the plane-of-array (POA), i.e., light falling on the module as it is titled at an angle. The complexity of this problem is further heightened when considering tracking technologies that move the tilt angle throughout the day. Therefore, the first aim of this research is to develop instrumentation and procedures for measuring such data accurately including standardisation of rear side irradiance (and therefore albedo which is the ratio of front and back irradiance); monitoring the tracking angle; and finally, the temperature and soiling as well. This lays the foundation for validation of different sun-tracking technologies via field testing, creating UK's one-of-a-kind outdoor experimental facilities for PV systems. This includes standard fixed-tilt systems placed at an optimal angle; Single-Axis-Tracking which follows the sun in one direction (typically east-west), and Dual-axis tracking which can follow in both east-west and north-south directions (more expensive, but highest potential for energy yield uplift). These critical measurements will help identify limitation in the modelling techniques (from simple empirical techniques to more complex computer intensive ray-trace models) used to estimate the POA irradiance and help improve accuracy of energy yield estimation by utilising the real-world data. Finally, the levelized cost of electricity can be mapped for different tracking technologies, and analysed in the context of dual-land use, electricity spot price markets, and environmental costs. The challenges above will be addressed by a collaborative effort from an international and industrial team, led by the University of Southampton, which includes pioneering researchers on bifacial tracking at NREL and SERIS; world-leading instrumentation expertise at NPL and the Chilbolton Observatory; and Corrie-Energy, a UK SME developing low-cost dual-axis trackers. The research will deliver key impact through improving global standards for bifacial tracking measurements; building open-source datasets for validated systems in the UK; and finally identifying economic and environmental viability. This will benefit industries across the sector, from SMEs manufacturing tracking systems, to asset managers installing utility scale systems.

Wave energy convertors (WECs) offer opportunities for niche (powering aquaculture and offshore stations) and grid-scale applications. However, disruptive innovation is essential to unlock the potential of wave energy, achieve step change reduction in cost of energy, and prove competitiveness against other renewable energy options. Here we investigate the opportunity to transform the development of WEC systems by utilising intelligent design concepts that exploit novel use of deformable materials. WECs based on deformable materials may offer improved performance, survivability, reliability, and reduced cost compared with steel or concrete alternatives for the following reasons: 1. To achieve a given resonant frequency, a flexible fabric device can be smaller and lighter. 2. Hydrodynamic characteristics of such a device can be modified by controlling its internal fluid pressure, enabling it to be tuned to suit incident wave conditions. These adjustments can be made by an on-board intelligent responsive system. 3. Controlled non-linear changes of geometry would enable a deformable fabric structure to accommodate or shed high loads without reaching critical stress concentrations, improving survivability and reducing installation and lifetime costs. 4. Flexibility opens up the possibility to use a range of PTOs, such as novel distributed embedded energy converters (DEECs) utilising distributed bellows action, electro active polymers, electric double layer capacitors or micro-hydraulic displacement machines. 5. A lightweight flexible structure with largely elastic polymer construction is unlikely to cause collision damage, and so is therefore a low risk option for niche applications, such as co-location with offshore wind devices. The performance of flexible responsive systems in wave energy, their optimisation in operating conditions, and their ability to survive storm waves, will be assessed through a programme of wave basin experiments and numerical modelling of different flexible WEC concepts. Survivability is a critical hurdle for all WEC concepts as by their nature they need to respond in energetic sea states while avoiding critical stresses in extreme seas. For a flexible responsive structure, this means avoiding concentration of stress (naturally avoided by collapse/folding) or of strain (avoided by use of a distributed PTO during operational conditions). Numerical models will be developed that account for complex interactions between wave action, deforming membrane structure, and internal fluid. The models will be informed, calibrated, and validated using results from materials testing and fundamental hydro-elastic experiments. Advantages and disadvantages of rubber-based, polyurethane and other reinforced polymer materials will be assessed in terms of manufacturing cost, join, bonding, and fatigue performance in the marine environment. The research will draw on origami theory and the technology of deployable structures to avoid problems with wrinkling, folding, or aneurysm formation, and an entirely new design may emerge through this innovative approach. We aim to demonstrate a pathway to cost reduction for flexible fabric WECs optimising for performance, structural design and manufacture for both utility scale and niche applications.

The proposed new CCP-WSI+ builds on the impact generated by the Collaborative Computational Project in Wave Structure Interaction (CCP-WSI) and extends it to connect together previously separate communities in computational fluid dynamics (CFD) and computational structural mechanics (CSM). The new CCP-WSI+ collaboration builds on the NWT, will accelerate the development of Fully Coupled Wave Structure Interaction (FCWSI) modelling suitable for dealing with the latest challenges in offshore and coastal engineering. Since being established in 2015, CCP-WSI has provided strategic leadership for the WSI community, and has been successful in generating impact in: Strategy setting, Contributions to knowledge, and Strategic software development and support. The existing CCP-WSI network has identified priorities for WSI code development through industry focus group workshops; it has advanced understanding of the applicability and reliability of WSI through an internationally recognised Blind Test series; and supported collaborative code development. Acceleration of the offshore renewable energy sector and protection of coastal communities are strategic priorities for the UK and involve complex WSI challenges. Designers need computational tools that can deal with complex environmental load conditions and complex structures with confidence in their reliability and appropriate use. Computational tools are essential for design and assessment within these priority areas and there is a need for continued support of their development, appropriate utilisation and implementation to take advantage of recent advances in HPC architecture. Both the CFD and CSM communities have similar challenges in needing computationally efficient code development suitable for simulations of design cases of greater and greater complexity and scale. Many different codes are available commercially and are developed in academia, but there remains considerable uncertainty in the reliability of their use in different applications and of independent qualitative measures of the quality of a simulation. One of the novelties of this CCP is that in addition to considering the interface between fluids and structures from a computational perspective, we propose to bring together the two UK expert communities who are leading developments in those respective fields. The motivation is to develop FCWSI software, which couples the best in class CFD tools with the most recent innovations in computational solid mechanics. Due to the complexity of both fields, this would not be achievable without interdisciplinary collaboration and co-design of FCWSI software. The CCP-WSI+ will bring the CFD and CSM communities together through a series of networking events and industry workshops designed to share good practice and exchange advances across disciplines and to develop the roadmap for the next generation of FCWSI tools. Training and workshops will support the co-creation of code coupling methodologies and libraries to support the range of CFD codes used in an open source environment for community use and to aid parallel implementation. The CCP-WSI+ will carry out a software audit on WSI codes and the data repository and website will be extended and enhanced with database visualisation and archiving to allow for contributions from the expanded community. Code developments will be supported through provision and management of the code repository, user support and training in software engineering and best practice for coupling and parallelisation. By bringing together two communities of researchers who are independently investigating new computational methods for fluids and structures, we believe we will be able to co-design the next generation of FCWSI tools with realism both in the flow physics and the structural response, and in this way, will unlock new complex applications in ocean and coastal engineering

Increasing energy demands, exhaustion of easily accessible oil resources and fears of climate change make renewable energy sources a necessity. Although it is evident that future power generation will result from a wide mix of technologies, photovoltaic cells have made astounding technical and commercial progress in recent years. Over the last decade renewable energy generation has been stimulated by tax concessions and feed-in tariffs. Large scale manufacturing of photovoltaics has benefited from this and progress along the learning curve necessary to achieve economies of scale in manufacture has been very rapid. However like all renewable energy sources today the cost per kWh of electricity from photovoltaics is greater than that generated by fossil fuels, although the gap has reduced quite dramatically in the last two years. The cost reductions in generation from photovoltaics have been achieved through innovative cell design, the use of lower cost materials, advances in power management electronics and lower profit margins. At the moment, >85% of new installations use wafered silicon cells of multi-crystalline or single crystal material. In these cases a key issue has been developing technologies which use thinner slices (using less silicon for a given area of solar panel) and moving to "solar grade" silicon. This type of silicon is less pure than the electronic grade used for integrated circuits and is cast into multi-crystalline ingots but it is very much cheaper. This is an important issues because before these developments as much as 50% of the cost of a cell could be attributed to the silicon material. An important cost reduction per kWh delivered has been achieved in this way despite solar grade silicon producing cells of lower conversion efficiency than electronic grade material. Further substantial reductions in cost could be achieved by using silicon produced by less energy hungry metallurgical processes, for example starting the manufacturing process by the reduction of quartz with carbon and applying low energy purification processes. This type of silicon, known as upgraded metallurgical silicon, is even less pure containing compensated dopants and metals which can act as important recombination centres so reducing the efficiency further. The aim of this proposal is to develop methodologies which are able to bring the efficiency of cells made from these cheap forms of silicon close to the efficiencies achieved from the higher cost electronic grade material. This could increase the efficiency of multi-crystalline solar grade silicon by around 5% absolute and even more in the case of upgraded metallurgical silicon. Current silicon cell structures work well because hydrogen (usually from the silicon nitride antireflection layer) passivates surfaces and bulk defects. In electronic grade single crystal this reduces recombination to insignificant levels. It doesn't work as well in solar grade multi-crystalline silicon or upgraded metallurgical silicon because there are regions, sometimes entire crystal grains, which are not passivated by the hydrogen. However other regions are of very high quality often as good as electronic grade silicon. We associate the resistance to passivation with specific types of defect observed in lifetime maps of slices. In this project we plan to identify the defects which show resistance to hydrogen passivation by using electronic and chemical techniques (carrier lifetime, Laplace deep level transient spectroscopy, SIMS, Raman spectroscopy and defect modeling). The key part of the proposal is to use our knowledge of defect reactions in silicon to develop alternative passivation chemistries which can be applied, during slice or cell production, to those defect species resistant to hydrogen passivation. In this way we would expect to make a very important improvement to the efficiency of the dominant solar PV technology.