Technology Transformation to Support Flexible and Resilient Local Energy Systems

Lead Research Organisation: Imperial College London
Department Name: Electrical and Electronic Engineering

Abstract

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.

Planned Impact

Academic impact: The academic sectors that will benefit from the methodological approaches developed in this project include: power electronics - by creating circuit techniques that break the design trade-offs that have previously limited progress on footprint and losses and incorporating resilience models into converter evaluation; operation of Multi-energy system in cities - by addressing the optimal coordination mechanisms among alternative energy resources to enhance urban resilience; energy system control - by developing a joint-forecasting-aided decentralised MPC algorithm for urban energy system under limited communication resource; and fault management - by characterising fault current and converter impedances and developing signal processing and machine learning method to analyse travelling waves in uncertain networks
We plan to disseminate learning through a number of impact routes. First, results will be published in leading international journals and conferences. Secondly, project partners will disseminate results through personal networks, including the Energy Futures Lab, the Universities High Voltage Engineering Network and the FLEXIS network. Thirdly, by sharing findings through the Energy System Integration Group (www.esig.energy).

Economic impact: Energy is the lifeblood to these urban economies and essential to continued prosperity. By developing new technologies and methods to enable maximum flexibility and resilience on existing network infrastructure, expensive network reinforcements can be avoided and solutions which provide the best possible value to bill-payers and taxpayers can be achieved. These ideas will then be presented as policy evidence directly to Energy Networks Association (ENA), National Infrastructure Commission and others. We will also publish in the Policy Briefing Papers and Technical White Papers of Energy Futures Lab to bring evidence to the wider policy community. Prof Strbac has a strong track-record of creating impact from such techno-economic evidence through adoption in industry standards and regulatory policy. We will build on this experience.
We expect to make policy contributions on the economic benefits decentralised energy networks with advanced real-time control such as peer-to-peer (P2P) trading, vehicle to grid (V2G) systems and coordinated operation of multi-energy vectors. We believe these technologies could lead to lower bills for customers and a benefit to economic activity in the UK through new business creation.
We will work closely with project partners (covering network operators, control system vendors and energy market innovators) to maximise opportunities for field trials and demonstration projects.
The UK's leading position in decarbonisation of energy gives and opportunity for UK companies to demonstrate new technologies in their home market and then create export sales of products and consultancy services.

Societal impact: A re-imagined provision of energy services to urban communities is a major research outcome of this project that has broader societal benefits beyond the economic. By encouraging self-consumption of local renewable and recovered energy, through perhaps community energy groups, a dialogue can be promoted in communities on how the transition to a zero-carbon energy system can be turned to the advantage of the community. There are also benefits in local air-quality. We will engage Community Energy South to help understand the nature of this opportunity. We will also target dissemination across FLEXIS partners such as local authorities and the Welsh Assembly.

Publications

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Chu Z (2021) Short Circuit Current Constrained UC in High IBG-Penetrated Power Systems in IEEE Transactions on Power Systems

 
Description OFGEM RII0-2 Challenge Group
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
Impact Ofgem established the RIIO-2 Challenge Group with the objective to provide challenge to the energy network companies on their Business Plans for RIIO-2 and to Ofgem on their framework for RIIO-2, on behalf of existing and future consumers. Independent report was delivered to OFGEM.
URL https://www.ofgem.gov.uk/system/files/docs/2020/01/riio-2_challenge_group_independent_report_for_ofg...
 
Title SimplexPowerSystem 
Description A set of tools and models configured to run in Matlab has been created and made available in open-source form on GitHub. The tools allows basic data about an electrical power gird to be assembled in Excel spreadsheet form and converter into a SimScape model suitable for running time-domain simulations and a matching small-signal state-space model available for stability analysis using standard Matlab tools. Underpinning this area set of standard models for grid-forming and grid-following inverters and synchronous generators. Models and tool were created to allow rapid verification of new techniques for participation analysis but are more widely useful than that so are being made available to the research community. They will be expanded by adding further equipment types as our work continues. Alongside the tolls are documentation and example grids that can be used in tutorial fashion. 
Type Of Material Computer model/algorithm 
Year Produced 2020 
Provided To Others? Yes  
Impact No impacts at this early stage 
URL https://github.com/Future-Power-Networks/Power-System-Analysis-Toolbox
 
Description Panel Presentation at ESIG Spring Workshop 2021 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Two-hour on-line panel discussing the cases for using grid-forming inverters in future inverter dominated electricity grids. Panel comprised 3 system operators, 2 equipment manufacturers, 1 engineering consultant and Prof Tim Green as an academic researcher
Panel was an open session of the ESIG (energy Systems Integration Group, https://www.esig.energy) Spring Workshop with 330 attendees from Australia, Europe and North America, mostly drawn from industry (system operators, equipment manufacturers and consulting engineers).
Recording available via ESIG YouTube channel at https://www.youtube.com/watch?v=BXHxtUWwy7I
Year(s) Of Engagement Activity 2021
URL https://www.youtube.com/watch?v=BXHxtUWwy7I