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.

Flexural transducer currently are only designed for operation in ambient atmospheric conditions, at frequencies of up to approximately 50 kHz, with a long wavelengths in fluids and therefore reduced measurement resolution in many cases. If we could find a way to increase the frequency range of operation of these devices, whilst at the same time creating new designs that could withstand high pressures and temperatures, a plethora of new applications will open up, in some cases enabling measurements to be made that could not otherwise be taken - that is what this project will do, establishing a world lead in this field of research of High Frequency Flexural Transducers. Techniques will be created that used the HiFFUTs for the non-destructive testing of low acoustic impedance materials such as aerospace composites, flow measurements and metrology in hostile environments. Flexural ultrasonic transducers (sometimes referred to as uni-morphs) operate through the action of the bending / flexing of a piezoelectric material that is attached to a passive material. This is exactly how an ultrasonic car parking sensor operates, and these devices operating at twice the maximum audible frequency of humans, of around 40kHz, have had a tremendous impact, particularly on the automotive sector. The key to the success of flexural transducers used in parking sensors lies in the fact that they are extremely sensitive and efficient, whilst at the same time they are relatively simple to construct and are extremely robust. Imagine the typical environment that these sensors have to survive in; high vibration, large fluctuations in operating temperature, corrosive, dirty and wet conditions - whilst operating at a low power with a high sensitivity. So what makes these flexural transducers attractive to the automotive sector, where there is high pressure to keep sensor costs low at the same time as the sensors being very reliable? The two key factors are that (1) the piezoelectric element is bonded to the inside of a metal cap and the rear of the cap is hermetically sealed, and (2) the flexing of the metal cap and thin piezoelectric element, either from piezoelectric excitation or the arrival of a pressure wave requires relatively little energy. There is currently a surprising lack of any published, rigorous scientific study on these types of small flexural transducers, even at low frequencies and nothing appears to have been attempted using these types of transducers in liquids or for non-destructive evaluation. The vibration characteristics of a HiFFUT are dependent on the combined response and interaction of all the sensor's components with the medium it operates within or upon. Usually the mechanical response of these transducers is dominated by the vibration behaviour of the passive flexing membrane of the transducer housing to which the piezoelectric is attached, rather than the thickness or diameter of the piezoelectric element bonded to the housing. There are related examples of MEMs based transducers that operate by a flexural membrane at higher frequencies such as Capacitive Micro-machined Ultrasonic Transducers and Piezoelectric Micro-machined Ultrasonic Transducers and whilst these are clearly elegant devices, there are clearly a number of significant advantages to the use of HiFFUTs in many industrial applications. The most useful modes of operation are probably the axisymmetric modes, which will generate axisymmetric wave fields and work will mainly focus on these, but there may be instances where an anisotropic wave field provides an advantage. Flexural transducers or HiFFUTs can also be driven at a number of axisymmetric harmonic modes or frequencies - using one transducer to cover a wide bandwidth, with each mode having a different directivity pattern will dramatically increase the depth and breadth of information that can be obtained. These transducers are going to find applications in a wide range of industrial application

Electricity infrastructure provides a vital services to consumers. Across the UK there are thousands of miles of overhead lines and other assets that are vulnerable to a number of environmental risks. Wind risks have caused more disruptions to power supplies in the UK than any other environmental risks. Despite their importance, the future risks associated with windstorm disruption are currently highly uncertain as the coarse spatial resolution of climate models makes them unable to properly represent wind storm processes. STRAIN will address two challenges for infrastructure operators and stakeholders who are urgently seeking to understand and mitigate wind related risks in their pursuit to deliver more reliable services: (i) Build upon state-of-the-art modelling and analysis capabilities to assess the vulnerability of electricity networks and their engineering assets to high winds. This will consider the impact of different extreme wind events, over different parts of the electricity network, the households and businesses connected, and also apply a model representing infrastructure inter-connections to understand the potential impact on other infrastructures that require electricity such as road, rail and water systems. (ii) Climate models provide very uncertain wind projections, yet infrastructure operators require an understanding of future climate change to develop long term asset management strategies. To provide the necessary information we shall work with the Met Office and benefit from new high resolution simulations of future wind climate using a 1.5km climate model. These simulations have proven capable of representing convective storm processes, that drive many storms across the UK, and have already proven that they better capture extreme rainfall events. These methods will be applied to a case study of an electricity distribution network. These are more vulnerable to windstorms than the high voltage national transmission network. STRAIN will therefore, by synthesising and translating cutting-edge research, provide electricity distribution network operators with a significantly improved understanding of wind risks both now and in the longer term. This will improve the reliability of electricity supply to UK consumers including other infrastructure providers reliant on electricity distribution networks, and reduce costs by enabling more effective allocation of investments in adaptation and asset management. Furthermore, it will help other infrastructure service providers better understand the impacts of electricity disruption on their own systems, and plan accordingly. The improved understanding of future extreme wind storms will provide benefits across an even wider group of infrastructure and built environment stakeholders.

A sensorless electric motor drive is the popular term for drives which do not use shaft mounted speed or position sensors. Sensorless operation is highly desirable for reasons of cost, simplicity and system integrity. However, it is well known that there are serious problems with sensorless motor drive control at zero and low speeds and this has been one of the main research topics in this field for many years. The conventional method for sensorless control, used in commercial products, is to estimate the machine flux and speed using a mathematical model of the motor. Below 1 to 2% base speed however, position and speed estimation using such a model deteriorates and speed and torque control is lost. There has been a recent impetus for zero speed sensorless drives for more-electric aircraft and vehicular applications. For the former, there is a requirement for direct electromechanical (EM) actuation of critical actuators in which locking of the mechanical transmission is not permissible. In the vehicular field direct EM drives will be required for the main drive train, and for power steering, active suspension and braking actuation. One approach to the solution of the zero speed problem, which does not require a machine model, has been to exploit the natural asymmetries or saliencies in AC machines. These saliencies are cause by magnetic flux saturation and the geometry of the construction of the motor itself. Flux or rotor position can then be tracked by processing the current response to a test voltage signal injection overlaid on the supplied motor voltage. These signal injection methods are now quite well understood, but do contribute to increased accoustic noise, reduced efficiency, the requirement for additional sensors, and an increase in bearing wear and electrical stress within the machine windings.The current proposal aims to overcome the above disadvantages by developing methodologies by which:1) No signal injection is required, the method being integrated with the fundamental voltage applied to the drive via the power converter. This eliminates the problems of extra noise, losses, bearing wear and electrical stresses.2) The requirements for sensors is substantially reduced (depending on the application). For bespoke applications (e.g. aerospace, automotive), the aim will be for one current sensor and one low cost di/dt sensor. For industrial standard drives the target aim is to use only the existing line current sensors. These aims are quite challenging. Mathematical feasibility of a non-signal injection method has been shown at Nottingham and the technique is currently subject to patent at the University. Practical investigation is now possible owing to advances in high-accuracy timing and sampling available in low-cost digital control systems.

Decarbonising both heating and cooling across residential, business and industry sectors is fundamental to delivering the recently announced net-zero greenhouse gas emissions targets. Such a monumental change to this sector can only be delivered through the collective advancement of science, engineering and technology combined with prudent planning, demand management and effective policy. The aim of the proposed H+C Zero Network will be to facilitate this through funded workshops, conferences and secondments which in combination will enable researchers, technology developers, managers, policymakers and funders to come together to share their progress, new knowledge and experiences. It will also directly impact on this through a series of research funding calls which will offer seed funding to address key technical, economic, social, environmental and policy challenges. The proposed Network will focus on the following five themes which are essential for decarbonising heating and cooling effectively: Theme 1 Primary engineering technologies and systems for decarbonisation Theme 2 Underpinning technologies, materials, control, retrofit and infrastructure Theme 3 Future energy systems and economics Theme 4 Social impact and end users' perspectives Theme 5 Policy Support and leadership for the transition to net-zero