Cambridge workshop report: New technologies for off-grid villages: a look ahead

15 January 2014

The purpose of the workshop was to introduce the Cambridge Smart Villages Initiative (SVI) and bring together leading researchers in the UK to discuss the current landscape of energy production, use and efficiency in rural communities in developing countries, as well as scientific developments and technologies that might be influential over the next 10-20 years.

Introductions and setting the scene
Professor Sir Brian Heap, Cambridge and Dr John Holmes, Oxford

The driving motivation behind the Smart Villages Initiative (SVI) is that energy access acts as a catalyst for development, enabling education and local business opportunities, improving health and welfare, and enhancing democratic engagement. The SVI aims to help achieve the United Nation’s goal of achieving universal access to electricity by 2030.  In particular, it aims to help achieve rural energy access through micro/mini-grids and home-based approaches. The SVI is currently funded by the Malaysian Commonwealth Studies Centre at Cambridge and the core team is applying for additional support from the Templeton World Charity Foundation.

The SVI aims to realize its goal through providing policymakers with insightful, bottom-up analyses of the challenges of village-level energy provision for development, and propose recommendations about how these challenges may be overcome. This will be achieved with the support of international experts in the natural and social sciences, and through the regional and global networks of organizations such as the European Academies Science Advisory Council (EASAC) and the InterAcademy Panel (IAP).  It is proposed to hold a series of six regional workshops that will bring together top African, Asian, American and European scientists and key stakeholders (e.g. entrepreneurs, NGOs, financers, policymakers etc.).   The workshops will start in June 2014 and be held in Tanzania (East Africa), Ghana (West Africa), India (South Asia), Malaysia (South-east Asia), Bolivia (South America) and Mexico (Central America).

Each workshop will be followed by a set of follow-up activities that include disseminating conclusions and recommendations through the workshop report, preparation of policy briefs and briefing meetings, training courses, entrepreneurial competitions and a final event with key stakeholders. Other activities will include a vision paper, a booklet of invited essays, a pocket guide for the media and tertiary students, a website and final workshops in Brussels and Addis Ababa.

Lighting, power electronics, communications and health
Professor Sir Colin Humphreys, Cambridge

Improving the energy efficiency of lighting would be one of the most straight-forward ways to decrease energy consumption, potentially by up to 50% according to the US Department of Energy.  LED lights are made from light-emitting semiconductors and are much more efficient (30-60% efficiency) than incandescent (5%) or fluorescent bulbs (20-25%).  LED lights are a good fit for off-grid villages because of they can be operated with only a solar cell and battery, and can provide continuous light for 100,000 hours (11 years), compared to about 1000 hours for incandescent bulbs.

Current LED lights use the man-made material Gallium Nitride as the semiconductor material, grown on small sapphire or silicon carbide wafers, but these are expensive. Sir Colin’s lab is developing LED lights which can be grown on 6-inch diameter silicon wafers in an automated process, therefore decreasing the cost, which is currently approximately £15 for a 60 Watt equivalent replacement LED bulb. Plessey, the Plymouth-based company producing GaN bulbs based on the Cambridge technology has already received an order for 20m bulbs from China, illustrating the impact these bulbs can have in both emerging and developed markets in the very near term.  In the longer term GaN LED lighting has the potential to benefit rural villages in a number of ways including producing deep UV radiation to destroy pathogens that cause water-borne illnesses, improving the efficiency of rechargeable consumer electronics, providing a basis for transmitting wireless internet using light waves instead of radio waves and enabling the production of more efficient solar cells.

Distributed energy for rural Africa: powering the un-grid
Dr Simon Bransfield-Garth, Azuri

Dr Bransfield-Garth’s presentation brought forward the premise that as markets in emerging countries are underdeveloped, current technology is adequate and the present focus should be on how to use currently available technology to meet market needs. The presentation also established that there is significant demand for off-grid solar in Africa and that as a result of demographics and potential economic development pathways, the demand for affordable consumer electronics that meet information, entertainment, knowledge and entrepreneurship needs will increase. The presentation also stressed the need to view the economic and social benefits of energy at the margin and advocated a tiered approach to energy demand and supply.

The presentation highlighted Azuri’s Indigo project where a 2.5W solar home system is sold as a pay-as-you-go energy service to households. This business model overcame the common barriers of a high up-front cost and continued maintenance. Field data were presented that suggested that Indigo has allowed households to save money and time and that there have been social and economic impacts. Indigo has helped deliver aspirations to younger generations, primarily by helping the generation to step up and leave behind the expectation of being poor.

Energy for development: business opportunities for community mini-grids
Professor AbuBakr Bahaj, Southampton

Professor Bahaj’s presentation described the thought process and outcomes of building an exemplar solar driven project based on community energy services company (ESCO) that supply power through a mini grid connected to businesses within the Kitanyoni’s village centre, Kenya in 2012. Outlying villagers purchase LED lanterns from the ESCO which they electrically charge at the businesses in the village centre. The project team worked closely with local partners, government and the villagers themselves to assess available resources, build the solar-powered mini-grid system, and train villagers to operate and maintain the system.  Establishing early community ownership through shares and membership was a key contributor to the project’s success.  Other important factors included local employment, supply chain, and the training of local people. The project ethos is to develop applicable and tailored technologies that were easy to implement and replicate in rural communities.

The project was implemented with support from the Research Council’s UK Energy Programme and focused on developing a system that would fit the needs of the local community and have a sustainable business case by delivering holistic value, especially in terms of productive enterprise enabled by access to power.  As a result of building the mini-grid, villagers have built five new buildings, created new sources of income from charging devices, renting use of appliances, selling water collected from the canopy that holds the solar panels and through the selling of power to the businesses. .  In addition, access to power has increased market activities by allowing shops to remain open after dark, improved conditions in the midwife’s clinic, and brought new kinds of business activities within the community as well as out of school hours educational services.  Keys to building future successful mini-grids for villages will need to take a broad range of factors into account including affordability, project economics, ownership finance, payment mechanisms, and systems for monitoring and evaluation.

Boosting the future efficiency of solar technology
Dr Andrew Musser, Cambridge

Dr Musser’s presentation presented some of the research undertaken by the Optoelectronics group at the Cavendish Laboratory. The group is currently looking at the fundamental principles behind solar cells with a view to understanding what physical properties can be harnessed to improve cell efficiency.  Currently, single junction solar cells are limited by the Shockley-Queisser limit that sets the maximum power conversion efficiency at approximately 33%. One method mentioned to improve efficiency is to design and make multi-junction solar cells, which can achieve approximately 45% efficiency. Design difficulty and high costs mean that multi-junction solar cells are not suitable for rural deployment. An alternative approach that is still in the early stages of research is to use singlet exciton fission in combination with a conventional single junction cell to achieve a theoretical maximum efficiency of approximately 44%. Stemming from this research, it is possible that within 5 to 10 years it may be possible to apply singlet exciton fission to silicon solar panels. This would likely increase efficiency by 2-5% which, given that efficiency gains in silicon have saturated, is a helpful improvement for rural villages.

Graphene-based dye-sensitized solar cells
Dr Tawfique Hasan, Cambridge

Dr Hasan’s presentation looked at grapheme-based dye-sensitized solar cells (DSSCs), which are exciting alternatives to conventional silicon-based solar cells due to their simple fabrication process, lower materials and production cost. They can have important implications when portable and easily deployable economic solutions to energy in remote locations are envisaged. Two components of the current generation DSSCs, namely the counter electrode (CE) and the dye, still have significant potential for further cost reduction. The CE commonly consists of a catalytic Platinum (Pt) film deposited on a transparent conductor like Indium Tin-oxide (ITO). Poor chemical stability, high cost and high temperature processing requirement are drawbacks of the well-established platinum counter electrode-based DSSCs. Graphene is a promising CE material in DSSCs due to its high exchange current density, low charge-transfer resistance high specific surface area and significantly lower cost than platinum. Current DSSCs commonly use synthetic dyes to absorb light for the conversion into electrical energies. These synthetic dyes require on tedious and expensive purification procedures. Natural dyes and their organic derivatives with comparable performance are non-toxic, biodegradable, low in cost and abundant. Thus, both graphene and natural dyes are ideal candidates for next generation economic, environmentally friendly solar cells.

In this project, we are employing graphene ink, pioneered in the Cambridge Graphene Centre. TiO2 photoanode inks are also being formulated. We are using natural tropical dye extracts from widely available leaf/flower extracts such as Pennisetum glaucum, Hibiscus sabdariffa and Caesalpinia pulcherrima as photosensitizers. Our approach to printed devices and use of graphene and natural dyes offer versatility, potential for mass production and cost reduction as well as conformable device form factors.

The project is at TRL3, ideally suited for academic investigation leveraging the strengths of Cambridge Graphene Centre (CGC) and Centre for Advanced Photonics and Electronics (CAPE) at the Engineering Department. The technology is potentially suited for deployment in rural villages in 5-10 years. The 6-month exploratory phase of the project was funded by Cambridge in Africa program (CAPREx) and the Alborada Trust. Support from The Royal Academy of Engineering is also acknowledged.

Water for all: technological and cultural implications
Professor Michael Depledge, Exeter

Most stakeholders agree that providing access to clean water is a major priority for rural villages where water-borne illnesses are the top cause of hospitalisations.  This presentation examined some lateral concerns of implementing new technologies in developing markets, particularly in relation to unanticipated environmental impacts, and suggested a number of questions for consideration.  The Life Straw was highlighted as one example of using affordable nanotechnology to remove both pathogens and contaminants in drinking water.  The presentation stressed, however, that questions remain around if the technologies such as nanoparticles might themselves be harmful to individuals or the environment and challenged us to consider all new technologies from alternative angles.


For example, changing global patterns of water consumption and the substantial amount of energy consumed transporting water should be considered when discussing energy provision for off-grid villages. Questions were also raised about how to plan for both anticipated and unintended consequences of access to clean water, such as exponential increases in demand with changing patterns of agriculture and diets with higher proportions of animal products.  Specific concerns were highlighted including how to manage waste generated from increased use of consumer products, cultural disruption by new technologies replacing roles held by community members (collecting water), increased dependence on new technologies and increased carbon and water footprints.


Bioenergy from plants and algae
Professor Alison Smith and Dr Beatrix Schlarb-Ridley, Cambridge

Recent developments and research on bioenergy from plants and algae were presented. Regarding bioenergy from plants, the presentation highlighted that further development is required for next generation biofuels that utilize the non-edible parts of crop plants, and that its usefulness in rural villages is likely to be limited due to the scale of infrastructure required for processing. Algae were highlighted as a potentially game-changing alternative, however algal agronomy is still in its infancy and advances in understanding algal biology will be key to sustainable production on a commercial scale.

A case study of a potentially deployable algal-culture system for energy production coupled with waste processing designed by Cambridge-based Sustainable OneWorld Technologies (SOWTech) was presented. The culture system is currently being trialed in the UK and potentially in Malawi in the near future. Another approach that is in its relative infancy was presented, in which rather than producing biomass, electricity is generated directly, via biophotovoltaics. Two examples of how this might be used were presented, one using algae in solar panels, and the other coupled with growth of crops (photosynthesis-fed microbial fuel cells). In addition, the potential use of microbial fuel cells for generating electricity while cleaning water was highlighted.

Biomass-fueled 5-20kW Stirling engine for off-grid applications
Mr Mike Dadd and Professor Nick Jelley, Oxford

Stirling engines are currently being used to generate power in space but can potentially be adapted to generate electricity for off-grid villages.   A Stirling engine converts heat to electricity by taking advantage of temperature differences to drive the expansion and contraction of gases to generate net power.  For renewable heat sources (e.g. solar and biomass), Stirling engines are better suited to converting heat into electricity (1-10kW) than internal combustion engines.  Stirling engines can achieve up to ~ 40 %efficiency but this is not necessary for off grid villages – overall system efficiency allowing, for the drive for low manufacturing cost, is likely to be nearer ~ 20 – 30 %.


The Oxford oil free linear design contains no bearings or friction-wearing parts so could potentially have an extremely long useful life. This would help to avoid the issues around maintenance and reliability that have been a problem with conventional designs. A bigger, multi-cylinder model configured to use biomass as a fuel is currently under development that could address some current operational hurdles.

Initial work to use solar energy as a power source for the engine led to the development of the Oxford Solar Cooker (funded by the Leverhulme Trust), which uses novel structures and reflectors to concentrate sunlight into an oven at a convenient height. It can be flat-packed for ease of transport and field trials in Africa are planned in collaboration with Dytecna in 2014.

Jugaad Innovation: challenges and opportunities in commercializing affordable solutions for low income communities
Professor Jaideep Prabhu, Cambridge

Western innovation processes are typically resource intensive, time consuming and focus on solutions for the wealthier portion of the world’s population.   In contrast, ’Jugaad’ innovators overcome harsh constraints in emerging markets by improvising effective solutions with limited resources and are inclusive of the four billion people who live at the base of the world economic pyramid, earning less than $9/day.  Solutions for this segment of the world’s population need to be designed around local behaviour and economics, including consideration of payment and distribution models since a significant proportion of the base of they pyramid is ‘unbanked’ and difficult to reach.


This presentation presented several case studies of successful jugaad innovation in developing countries where entrepreneurs were frugal, flexible and inclusive in their solutions.   Innovations profiled include the Mitticool clay fridge which cools through evaporation alone, a baby warmer 100x cheaper than a hospital incubator, telemedicine approaches for managing diabetes in remote communities, solar energy as a service, the low cost Tata Nano and the Aakash tablet designed to deliver education through broadband.  Several Western companies are starting to mesh jugaad approaches with their conventional innovation processes, including GE who have developed a battery-operated light-weight ECG machine and Nokia who specifically designed the Nokia 1100 for emerging markets.  To address payments issues, M-PESA has been particularly successful in Kenya and has had the added benefit of decreasing corruption by making payments trackable.


Professor Peter Guthrie and Dr Heather Cruickshank, Cambridge

The presentation drew on the experience of researchers at the Centre for Sustainable Development, Cambridge. A number of key points were raised and a final take-home message presented. One of the key points mentioned was the need to be wary of relying on simplifications of complex data, as well as toolkits and decision support systems. A second key point was that experience suggests that the provision of raw infrastructure by itself will not lead to development and that there is a big disconnect between the top and bottom. For example, the values of a community, in relation to infrastructure, may differ significantly from donor or academic assumptions.  A third point was that it may be beneficial to design and deploy solutions that are adequate rather than comprehensive and allow for technology to be resilient. The take-home message was that achieving universal access to energy can only be achieved through holistic, integrated and interdisciplinary thinking.

Final discussion and overview: where we are and where we could be by 2030

Three streams of research or areas of research were identified from the workshop. The first stream focused on the transitional problem: how can we ensure that using today’s technology does not inhibit the use of future technology? The second stream of research focused on social acceptability and the third stream of research on the business model. It was recognized that social acceptability and the business model are interlinked and that it is only through developing a socially acceptable business model that sustainability can be achieved.

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