Resilient Electricity Networks for a productive Grid Architecture (RENGA)

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

Abstract

Electricity access is widely acknowledged as one of the key enablers of human development. Bringing electricity to low income areas in the developing world involves great technical, geopolitical and socioeconomic challenges. In recent years, autonomous electricity supply systems (AESS) have found a role in replacing kerosene lamps and candles as sources for basic lighting. However, their power rating was too low to power even small machinery, which made them have very little impact on the way people produce goods. According to the well-established power systems planning paradigm, the way to enable electricity access suitable for more productive applications is to build new transmission corridors to ship power from large power plants to isolated areas where it will be distributed using regional distribution networks. While this approach proved successful in the mid twentieth century, it often incurs prohibitive costs that make such projects infeasible in developing countries. One of the main issues of the old paradigm is that it misses the opportunity to use distributed energy resources (ie small scale generation, energy storage, etc) available today to drive the costs down and achieve better energy supply. The aim of this project is to bring some light over this matter by investigating a new approach where the electrical network would start from the local interconnection of small scale AESS. This ambitious goal will require the investigation of a suitable technological solution to link multiple AESS together, the development of new tools that are suitable to optimise the operation and planning of a network of interconnected AESS with models of demand and generation tailored for rural electrification applications. The work will use Rwanda as the main study case with the cooperation of the University of Rwanda, that will provide support for the derivation of models and will study and characterise the most interesting productive uses of electricity to meet the specific needs in rural Rwanda. The work will also be carried in collaboration with BBOXX and Meshpower, two British companies started by alumni of Imperial College London that commercialise AESS in several countries around the world including Rwanda.

Planned Impact

This project will investigate the expansion of an electric power system starting from the aggregation of interconnected autonomous electricity supply systems (AESS). Within the project, we will research the technology required to build the interconnection network with affordability, safety, easy of installation and resilience in mind. We develop tools for the optimisation of the operation of such system and planning methods that will make extensive use of smart enabling technologies (e.g. flexible demand, energy stored) in order to lower the costs of building network infrastructure while achieving high resiliency. We will also develop models of demand and generation for planning studies and validate existing openly available data against historical data provided by several industrial partners. As part of the project, a team will also study potential productive uses of electricity in order to gain insight about what the real benefits of providing better access to electricity would be and providing specifications that will be used in the work on technology development and planning.

The work within the project is expected to have impact across different fields (ie power electronics, power systems engineering, energy policy) and to be of interest to academics, industry and policy makers. Impact in within the academic community will be maximised through the dissemination in specialised conferences and journal publications. Impact on industry and policy makers will be achieved through the collaboration with the AESS manufacturers involved in the project and through the influence of the work within the pres oject in our existing collaboration ties with distribution network operators (e.g. UKPN), utilities (EDCL in the project) and regulatory bodies (e.g. OFGEM).

A further impact expected in the project is the development expertise in the target LMIC countries. In this project we will work in collaboration with the University of Rwanda and the Tribhuvan University in Nepal. The interaction within the project in the form of co-supervision of the research assistants involved in the University of Rwanda and the multiple mutual exchanges between the institutions, we aim to establish long lasting ties with both institutions that will give more international visibility to these universities to attract researchers and prospect students. We have already been part in the validation of an MSc programme in the University of Rwanda as external advisers and the expectation is to use the project meetings to be part of teaching activities within the courses taught at the university.

Publications

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Description We are at an early stage of the project but we have already achieved one of the objectives of our technology work package. We have developed a new device, a DC/DC converter, that can be used to export power from one mini-grid to another. For example, it can be used to connect together the PV panel generation of two or more villages that are within a kilometer from each other. The device was specifically designed to be easy to deploy with minimal effort and make mini-grids from different manufacturers compatible. This is achieved by not coupling the low level dynamics of the two mini-grids and by providing galvanic isolation to connect multiple systems with different earthing arrangements together. A first demonstration prototype has been created with an input voltage of 48V and an output voltage of 160-240V, the wide output range enables the use of robust controllers that can be deployed without knowing the exact length of the conductors and their exact resistance. As of March 2020 a draft of a journal paper describing the details of the converter is being prepared to be submitted to IEEE Trans. on Power Electronics.
Exploitation Route We plan to demonstrate the operation of our DC/DC converter in a real mini-grid owned by one of the industry partners of the project, Meshpower within a year. The details of the converter have been described in a journal paper that is going to be submitted within 6 months. The adoption of the converter by other manufacturers is of interest of our industry partners because standards for low voltage DC distribution for rural electrification are not well established yet.
Sectors Energy

 
Description A seminar organised by the Energy Futures Lab at Imperial College London about Project RENGA 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Other audiences
Results and Impact The Energy Futures Labs is an institute at Imperial College London that fosters multidisciplinary research across the College around the Energy theme. They run 1 hour weekly seminars that are openly advertised for anyone to attend. I gave a talk to present project RENGA and the state of our work. There were about 40 people attending, around 10 were academics and PhD students from my department, some 10 people from industry and around 20 other academics and PhD students from other departments of Imperial College.

I received many expressions of interest about the project including a couple of people from industry that requested further information and offered help improving the models of distributed generation for electrification.

We also published a blog post with further information about the project and the topics covered in the talk:
https://energyfutureslab.blog/2019/02/28/building-an-electrical-system-from-the-bottom-up-by-interconnecting-minigrids/
This has been advertised through Twitter and the webpage of the Energy Futures Lab.
Year(s) Of Engagement Activity 2019
URL http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/administration/energyfutureslab/events...
 
Description An interview for an article about Mini-Grids to be published in Wired UK 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I was interviewed by a Ms Delle Chan from Wired UK as part of an article on mini-grids that is pending to be published in Spring 2020. The interview took place in January 2020; I will update this entry once the article becomes available online.
Year(s) Of Engagement Activity 2018,2020