The UK electricity system faces challenges of unprecedented proportions. It is expected that 35 to 40% of the UK electricity demand will be met by renewable generation by 2020, an order of magnitude increase from the present levels. In the context of the targets proposed by the UK Climate Change Committee it is expected that the electricity sector would be almost entirely decarbonised by 2030 with significantly increased levels of electricity production and demand driven by the incorporation of heat and transport sectors into the electricity system. The key concerns are associated with system integration costs driven by radical changes on both the supply and the demand side of the UK low-carbon system. Our analysis to date suggests that a low-carbon electricity future would lead to a massive reduction in the utilisation of conventional electricity generation, transmission and distribution assets. The large-scale deployment of energy storage could mitigate this reduction in utilisation, producing significant savings. In this context, the proposed research aims at (i) developing novel approaches for evaluating the economic and environmental benefits of a range of energy storage technologies that could enhance efficiency of system operation and increase asset utilization; and (ii) innovation around 4 storage technologies; Na-ion, redox flow batteries (RFB), supercapacitors, and thermal energy storage (TES). These have been selected because of their relevance to grid-scale storage applications, their potential for transformative research, our strong and world-leading research track record on these topics and UK opportunities for exploitation of the innovations arising. At the heart of our proposal is a whole systems approach, recognising the need for electrical network experts to work with experts in control, converters and storage, to develop optimum solutions and options for a range of future energy scenarios. This is essential if we are to properly take into account constraints imposed by the network on the storage technologies, and in return limitations imposed by the storage technologies on the network. Our work places emphasis on future energy scenarios relevant to the UK, but the tools, methods and technologies we develop will have wide application. Our work will provide strategic insights and direction to a wide range of stakeholders regarding the development and integration of energy storage technologies in future low carbon electricity grids, and is inspired by both (i) limitations in current grid regulation, market operation, grid investment and control practices that prevent the role of energy storage being understood and its economic and environmental value quantified, and (ii) existing barriers to the development and deployment of cost effective energy storage solutions for grid application. Key outputs from this programme will be; a roadmap for the development of grid scale storage suited to application in the UK; an analysis of policy options that would appropriately support the deployment of storage in the UK; a blueprint for the control of storage in UK distribution networks; patents and high impact papers relating to breakthrough innovations in energy storage technologies; new tools and techniques to analyse the integration of storage into low carbon electrical networks; and a cohort of researchers and PhD students with the correct skills and experience needed to support the future research, development and deployment in this area.

The ever increasing demand for electricity consumption accompanied by environmental pressures impose a continuing need for electrical systems modification and growth, partly because of changing operational practices resulting from de-regulation and, partly, due to the increased use of distributed generation, which is changing the demands on transmission and, especially, distribution lines. But for many years now, the opportunities for installation of new lines have become very limited because of public concern over visual and other environmental impacts, and it is clear that extensions to system capacity will have to be met substantially without new lines.The voltage rating and the insulation coordination of transmission and distribution lines is determined by a combined consideration of the voltage stress applied to the line and its electrical strength. The stress arises from overvoltages due to switching transients or lightning surges. The magnitude of the switching overvoltage is controlled by the characteristics of the system components, and is more critical at the highest operating voltages. Lightning overvoltages, on the other hand, are of much larger magnitudes and are more onerous to distribution systems.IEC 60071 makes recommendations for the gaps and clearances to be used for specific voltage levels, and individual operators will then adopt safety factors above and beyond these recommendations, depending upon local conditions. Pollution, for instance, may reduce the breakdown voltage by up to 50%. These adopted clearances are usually very generous and can be optimised using modern equipment and practice.The investigators have researched for many years the possibilities for compact lines and substations through improved co-ordination of insulation and the use of polymeric insulators and more effective protective devices such as ZnO surge arresters. This programme, therefore, proposes to apply the compact line concepts to the up-rating of existing lines. It will involve statistical studies of switching and lightning surges that account for various parameters which affect the overvoltage magnitudes, such as closing times for circuit breakers and analysis of the possible state of the line in order to minimize the risk of re-closing onto trapped charge. The statistical variations of stress and strength of the system will be combined in a voltage-frequency plot to determine the risk of failure, which has to be minimized within economic constraints. The stress will be presented as the probability of a certain overvoltage occurring, and its distribution along a line will be controlled by the judicious placement of modern ZnO surge arresters. Electrical strength, on the other hand, can be presented as a probabilistic breakdown curve. It will be primarily derived from consideration of the breakdown curves taking into account the critical clearances at the tower and along the line. These principles have been studied over the years, but present-day pressures are causing a re-evaluation of the conventional limits and methodology. This is also supported by the excellent performance of modern ZnO surge arresters in controlling overvoltages and the superior pollution performance of new polymeric insulators. The programme will also include laboratory and field experimental programmes to test and characterise the new devices and configurations to be used for the compact design of the uprated lines. The main output of the programme is to establish well researched fundamental principles that will allow an efficient and safe design for the future transmission and distribution lines.The basis of this programme has been proposed by HIVES, Cardiff University and then moderated by discussions with an industry group involving National Grid, four UK DNOs, ESB and three line construction companies, whose views are embedded in the proposed programme.

Before high voltage plant fails there is generally a period when degradation of the insulation system occurs, this may be a number of years. The key to improving the assessment of the equipment condition and life expectancy lies in identifying and characterising the stages of degradation. It is widely recognised that the degradation phase, irrespective of the cause, results in small sparks being generated at the site(s) of degradation. These electric sparks are generally referred to as partial discharges(PD). The characteristics of the sparks are influenced by the materials and stresses at the fault site. Improvement in their detection and characterisation will provide information on the location, nature, form and extent of degradation.The current detection process is severely compromised in practical on-site testing. These PD pulses are extremely small and hence, irrespective of the particular strategy being applied to detect them(electrical or acoustic), detection equipment must be very sensitive. In the field, this makes it prone to the influence or external interference or 'noise' from the surrounding environment and electrical/mechanical infrastructure. At best, this results in data corruption and compromises the efficiency of the condition assessment. At worst, it stops the technique from being of any use as the 'noise' signal exceeds the level of partial discharge activity.To solve the problems associated with noise a number of methods have been tried such as: screening and filtering, the application of analogue band-pass filtering, matched filters, polarity discrimination circuitry, time-windowed methods and digital filters. Each of these is, however, applicable to only certain types of noiseIn a recent study the author compared the matched filter, the traditional filter and the Discrete Wavelet Transform (DWT) in PD measurement denoising and has proven DWT provides the best solution in practical measurement when strong noise is in presence. Furthermore, DWT is the only method which allows reconstruction of the PD pulse.Having evolved from the Fourier Transform(FT), WT is particularly designed to analyse transient, irregular and non-periodic signals. Ideally, if a wavelet can be selected to match the PD pulse shape, the PD pulse could be extracted from any strong noise signals. Though the WT generates more information than the FT, it is inherently more complex than the FT and involves procedures dependent on the shape of the signals to be extracted from noisy data, the record length and the sampling rate. Dr. Zhou in the Insulation Diagnostics Group at the GCU was the first to study the optimal selection of the most appropriate wavelets, the optimal number of levels and level-dependent thresholding algorithm for automatic PD pulse extraction from electrically noisy environments using DWT. This innovative work has been proved to be effective in a number of measurement platforms. However, the application of DWT still requires significant experience at the moment when pulses of different shapes exist. The proposed research is to build on the experience and success already gained at GCU and to develop a methodology which allows the DWT to be applied to various PD measurement systems irrespective of their mechanism and bandwidth for PD data denoising and PD pulse reconstruction and classification.The outcome of the proposed research will be algorithms which can identify all types of transient pulses contained in data under analysis and present them separately in time domain. This would allow the identification and classification of various PD activities from PD measurements and production of phi-q-n diagrams which, in conjunction with pulse shapes, provides significantly improved means for plant diagnosis.

Before high voltage plant fails there is generally a period when degradation of the insulation system occurs, this may be a number of years. The key to improving the assessment of the equipment condition and life expectancy lies in identifying and characterising the stages of degradation. It is widely recognised that the degradation phase, irrespective of the cause, results in small sparks being generated at the site(s) of degradation. These electric sparks are generally referred to as partial discharges(PD). The characteristics of the sparks are influenced by the materials and stresses at the fault site. Improvement in their detection and characterisation will provide information on the location, nature, form and extent of degradation.The current detection process is severely compromised in practical on-site testing. These PD pulses are extremely small and hence, irrespective of the particular strategy being applied to detect them(electrical or acoustic), detection equipment must be very sensitive. In the field, this makes it prone to the influence or external interference or 'noise' from the surrounding environment and electrical/mechanical infrastructure. At best, this results in data corruption and compromises the efficiency of the condition assessment. At worst, it stops the technique from being of any use as the 'noise' signal exceeds the level of partial discharge activity.To solve the problems associated with noise a number of methods have been tried such as: screening and filtering, the application of analogue band-pass filtering, matched filters, polarity discrimination circuitry, time-windowed methods and digital filters. Each of these is, however, applicable to only certain types of noiseIn a recent study the author compared the matched filter, the traditional filter and the Discrete Wavelet Transform (DWT) in PD measurement denoising and has proven DWT provides the best solution in practical measurement when strong noise is in presence. Furthermore, DWT is the only method which allows reconstruction of the PD pulse.Having evolved from the Fourier Transform(FT), WT is particularly designed to analyse transient, irregular and non-periodic signals. Ideally, if a wavelet can be selected to match the PD pulse shape, the PD pulse could be extracted from any strong noise signals. Though the WT generates more information than the FT, it is inherently more complex than the FT and involves procedures dependent on the shape of the signals to be extracted from noisy data, the record length and the sampling rate. Dr. Zhou in the Insulation Diagnostics Group at the GCU was the first to study the optimal selection of the most appropriate wavelets, the optimal number of levels and level-dependent thresholding algorithm for automatic PD pulse extraction from electrically noisy environments using DWT. This innovative work has been proved to be effective in a number of measurement platforms. However, the application of DWT still requires significant experience at the moment when pulses of different shapes exist. The proposed research is to build on the experience and success already gained at GCU and to develop a methodology which allows the DWT to be applied to various PD measurement systems irrespective of their mechanism and bandwidth for PD data denoising and PD pulse reconstruction and classification.The outcome of the proposed research will be algorithms which can identify all types of transient pulses contained in data under analysis and present them separately in time domain. This would allow the identification and classification of various PD activities from PD measurements and production of phi-q-n diagrams which, in conjunction with pulse shapes, provides significantly improved means for plant diagnosis.

In order to meet UK Government targets to reduce CO2 emissions by 80% by 2050, rapid growth in electricity generation from intermittent renewable energy sources, in particular, wind, is required, together with increasing constraints on the operation and environmental performance of conventional coal and gas-fired plant. Unprecedented demands for operational plant flexibility (i.e. varing power output to reflect demand) will pose new challenges to component integrity in ageing conventional plant, which it is widely recognised will play a crucial role in maintaining security of supply. In parallel, demands on fuel flexibility to reduce emissions, i.e. firing gas turbine plant with low-carbon syngas or biogas and firing/cofiring steam plant with biomass, will create new challenges in plant engineering, monitoring and control, and materials performance. Improved plant efficiency is a key requirement to cut emissions and to make decarbonisation economically feasible. The continuous development of novel, stronger high temperature materials may also enable component replacement, rather than complete new build plant, to maintain the essential reserve of conventional generation capacity. Finally, the decarbonisation transition involves new and complex economic and environmental considerations, and it is therefore important that these issues of sustainability are addressed for the development of future conventional power plant. The research programme will consider the key issues of Plant Efficiency, Plant Flexibility, Fuel Flexibility and Sustainability and how these four intersecting themes impact upon plant operation and design, combustion processes in general and the structural integrity of conventional and advanced materials utilised in conventional power plants. Outcomes from the proposed Research Programme include: - Improved understanding of the complex relationship between plant efficiency, fuel flexibility, plant flexibility, component life and economic viability - Novel approaches for monitoring and control of future conventional power plants - Improved fuel combustion and monitoring processes to allow use of a wider range of fuels - Improved understanding of structural materials systems for use in components with higher operating temperatures and more aggressive environments - Improved coating systems to protect structural materials used in power plant components - New models for optimisation of operating conditions and strategies for future conventional power plants The consortium comprises six leading UK Universities with strengths and a proven track record in the area of conventional power generation - led by Loughborough University, working together with Cardiff and Cranfield Universities, Imperial College London and the Universities of Nottingham and Warwick. The Industrial Partners collaborating in this project include several major UK power generation operators, Original Equipment Manufacturers (OEMs), Government laboratories and Small and Medium Sized (SMEs) companies in the supply chain for the power generation sector. The Energy Generation and Supply Knowledge Transfer Network will be a formal delivery partner of the consortium. The proposal has been developed following extensive engagement with the industrial partners and as a result they have made very significant commitment, both financial and as integrated partners in the research programme.