Technology Transformation to Support Flexible and Resilient Local Energy Systems

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Deep changes are happening in the supply side of energy systems. The UK has halved carbon emissions from electricity system from over 150 million tonnes in 2012 to under 70 in 2018 and China is adding about 20 GW of wind generation capacity per year and has replaced all buses in the city of Shenzhen with electric busses. Very clearly there is much more to do: the remaining decarbonisation of electricity, the electrification of other sectors and sourcing alternative, zero-carbon fuels.Cities have traditionally been huge consumers of energy brought in from their hinterland and yet load growth in energy networks is inevitable as more services, notably transport, are decarbonised through electrification and building density increases through re-development of with taller buildings. The traditional response to this, adding more plant and equipment, is recognised as being an inefficient. An interesting trend is the emergence of Local Energy Systems (LES) and Multi-Energy Micro-Grids (MEMG). LES and MEMG are a means for raising self-consumption of local energy resources; tapping into sources of flexibility in how the services derived from energy; using local services for both local and national control and moving to a smart ways of ensuring resilience. The recent power outage in the UK (9/8/19) highlighted that transport systems and other urban infrastructure are particularly vulnerable. A re-imagining of how resilience is provided in the urban setting could hugely reduce that vulnerability.Despite the differences between the histories and geographies of cities in China and the UK, we find common challenges and a complementary set of research expertise. This project brings together experts in power electronics, optimisation, control and fault-management from UK and China.Existing energy networks, especially electricity networks, were designed assuming power enters a city from remote power stations and the network inside the city distributes this. This led to a radial set of lines spreading out from substations. This structure is unable to support the formation of flexible microgrids around local generation and storage resources. We propose to re-structure the legacy networks using power electronics devices that give controlled power flows between previously unconnected networks points. This opens up dynamically restructuring the power flow in urban areas to allow greater local self-consumption of energy, for instance moving solar power residential properties to work-place charging of electric vehicles. It also allows islands to be formed in reaction to power cuts that keep essential services running while placing non-essential services on hold. We also look at hardware and control issues. The hardware for electronic routing of power has been discussed in principle but it is too large and not efficient enough to be used in urban settings. We will work on new forms of modular power converter that raise efficiency, reduce physical volume and provide resilience to component failures. Control systems for energy networks are centralised: they gather data from across large areas, make decisions and then issue commands. The microgrid concept changes this to a decentralised approach. A key benefit of decentralisation is the ready access to information about flexibility in energy consumption, e.g which electrical vehicles could delay charging or might supply power to aid with a power cut. Local control also gives opportunities to run the heat/cooling of buildings, the transport energy system and the electricity system as an integrated whole. This can lead better integration of renewable energy and therefore deep decarbonisation but requires a major step forward in managing uncertainty over the local energy resources and demands. We will bring the techniques of stochastic optimisation and machine learning to bear on this problem and devise a control and operations framework for smart urban energy systems.