Affordable Perovskite Solar Irrigation Systems for Small-holder Farmers in Ethiopia (APSISSFE)

Over 85 million Ethiopians depend on rain-fed agriculture. Climate change is increasing vulnerability and poverty amongst small-holder farmers, 21% of whom are female headed. However, women are responsible for about 40% of agricultural activities in Ethiopia. Research by Ethiopian partners in this project shows that the provision of small, solar-powered water pumps to irrigate vegetables and cash crops is a highly effective means of increasing resilience to climate-induced stresses and shocks, enhancing household food security, producing of cash crops, reducing women's labour, and ultimately enabling escape from the poverty cycle. Unfortunately, such irrigation systems are presently beyond the means of most farmers.

We propose to drop the cost of solar irrigation systems to a level affordable for Ethiopian small-holder farmers by: (i) advancing the science required to increase the performance and stability potential of halide perovskite photovoltaics (PV) cells; (ii) customizing the engineering required by significantly enhancing the efficiency of power electronic motor drive for pumps to the precise requirements of Ethiopian smallholders; and (iii) taking an Inclusive Innovation approach to co-designing the whole system with end-users to ensure that it is locally-appropriate and effectively reduces women's work.

We propose that the lead halide perovskites constitute an ideal emerging solar power technology to enable inclusive manufacture in Ethiopia of community-level solar powered irrigation systems because these materials can be printed at relatively low-cost on lightweight, flexible substrates. Here, we focus on solving critical interface loss and stability issues in perovskite solar cells that currently inhibit their commercial deployment. Concomitant with this, we will enhance the engineering of the irrigation system by developing modular and scalable solar inverters using advanced power electronic technologies and precisely designing the pump for small farms with shallow water tables. The solar powered irrigation system will be deployed in Ethiopia to ensure socio-economic and environmental appropriateness and provide a platform for scaled local engineering of the systems.

This proposal represents an innovative and unique programme of leading-edge experimental science and systems engineering studies, which are of direct relevance to enhancing economic development and welfare in Ethiopia. The interdisciplinary project will explore some of the central structure-composition-property issues of halide perovskite interfaces and their integration into systems, which brings together the complementary expertise of the applicants and will exploit techniques in which the UK is internationally competitive and in many aspects internationally leading. The PI, Co-Is and project partners have strong national and international reputations in their fields and an impressive track record in delivering research of the highest quality.

This research will target UN Sustainable Development Goals (UN SDG) 7 affordable clean energy, SDG6 access to water, SDG1 poverty and SDG2 food security. The proposed low-cost and high-performance solar system and converter is a timely solution to help Ethiopia to alleviate limitations on utilization of its available energy resources poverty in a sustainable and low-cost way. The nature of low cost and simple assembly of the solar and power module makes it suitable for local manufacturing and implementation, offering tangible cases for local entrepreneurship and small business initiatives for which the government gives a great attention towards expanding the manufacturing sectors. This collaborative project will help promote research and education on Electrical Engineering and Renewable Energy in Ethiopia.

Realising the value of disruptive technologies that make use of novel materials relies critically upon the prior understanding of material properties, device physics and manufacturing techniques. Our adventurous research programme is timely as sets out a bottom-up approach for advancing perovskite semiconductors towards this goal, whereby new insight into their semiconductor physics will drive further increases in device performance. In the research area of inexpensively deposited semiconductors, the UK has long been recognised as a centre of excellence and we seek to apply our expertise in order for this position to be preserved. Furthermore, the main discoveries behind high-efficiency perovskite photovoltaics devices were made in the country; to cement the status of these technologies as 'made in the UK' it is vital that research backing continues so that domestic industries (e.g., partner Oxford PV) and IP portfolios can grow and stay ahead of the international competition.

This proposal resides within the EPSRC 'Solar Technology' theme, which identifies 'potentially game-changing perovskites' as a focus, and 'Materials for Energy' theme, which has been identified as an area to grow. Our research programme fits with underpinning applications in the grand challenge areas of Energy, Environment and Manufacturing. Specifically, our research aligns well with current network hubs such as SuperSolar Network. In general, our work falls under the strategic themes of Energy and Manufacturing the Future, the latter through our commitment to identify and demonstrate scalable treatment processes that enhance optoelectronic performance. At its heart, this research concerns fundamental surface science and applied device work in perovskite semiconductors; topics that fall naturally under the themes of Physical Sciences and Engineering. With a focus on energy material interfaces, the work aligns directly with the scope of the EPSRC Centre of Advanced Materials for Integrated Energy Systems (CAM-IES) network, further boosting industry-academia links and expertise in these areas. The work will also utilize the Royce Institute, contributing to the growing expertise within this facility to make it truly world-class.