As climate change threatens to exacerbate water scarcity and food insecurity in many parts of Africa, solar water pumps combined with sustainable irrigation practices could boost the climate resilience and livelihoods of millions of farmers.
But which farmers are in the right places to benefit from these pumps? And how do the companies that manufacture and distribute them ensure solar irrigation is part of a sustainable package of solutions to water scarcity and not part of the problem? One answer is solar suitability maps.
In 2018, the International Water Management Institute (IWMI), supported by the CGIAR Research Program on Water, Land and Ecosystems (WLE) and the USAID-funded Innovation Lab for Small-scale Irrigation (ILSSI), began mapping solar irrigation suitability in Ethiopia. These maps pinpointed potential areas for smallholder farmers to introduce solar irrigation without depleting water resources.
With funding from Germany's Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), IWMI then refined the mapping framework. This was done using a multi-criteria evaluation that combined information from several geospatial drivers for solar-based irrigation. The data, which was sourced from various national and international open access databases, included solar irradiation, groundwater levels and storage, aquifer productivity, proximity to rivers and small dams, soil characteristics, crop and land suitability, population, roads and travel time to markets.
The resulting framework was translated into an online interactive tool for sub-Saharan Africa. Geospatial information on the suitability of areas for scaling up solar irrigation is now available for the entire region.
In developing the tool, researchers paid particular attention to environmental sustainability. This was done by specifying sustainable sources of water for irrigation – renewable groundwater – while taking into account the water necessary for maintaining natural ecosystems. In other words, the maps not only considered areas that are suitable for solar irrigation but also those that may not be suitable and should potentially be avoided to prevent long-term water resource depletion.
Reaching a wide audience
The tool is aimed at development banks, private sector companies, agriculture, water and irrigation ministries and technical experts. In collaboration with GIZ, the tool was integrated into the Toolbox on Solar Powered-Irrigation Systems (SPIS) to make its mapping powers available to a wider audience.
Established by the global initiative Powering Agriculture: An Energy Grand Challenge for Development, the SPIS Toolbox consists of modules and user-friendly tools, including calculation sheets, checklists and guidelines. The modules and tools address issues such as assessing water requirements, the sustainable design and maintenance of a SPIS, as well as financial viability.
The latter is a particularly important consideration for companies operating in or entering the solar irrigation market. Recent studies show that solar photovoltaics can provide a cost-effective energy solution to irrigation development in sub-Saharan Africa. By including this information in the solar mapping framework, IWMI was able to leverage the insights into the cost-effectiveness of adopting solar irrigation compared to diesel irrigation in specific areas.
Working with Futurepump, a solar pump manufacturer that specifically targets smallholder farmers, enabled IWMI to validate the maps across a large part of sub-Saharan Africa.
"Most of our around 8,000 pumps are equipped with remote monitoring technology, which tells us where they are located and also the volumes of water they are pumping. We analyze this data in a bespoke dashboard and share it with IWMI and other research organizations," explained Toby Hammond, Futurepump's Managing Director.
"There are, in fact, huge areas in Africa where there is plenty of water available that can be used for farming in a sustainable way. But, of course, there are other locations where water tables are dropping and there has been too much unregulated extraction of water. Our vision is that by collaborating with knowledge partners like IWMI and sharing our data openly, we can enable policy makers to develop evidence-based local regulatory frameworks that strike the right balance between conserving water and empowering low-income farmers to feed their families and communities using solar irrigation."
This is already happening in Ethiopia, where several IWMI recommendations to make water resources more resilient to climate change have been incorporated into the country's revised National Water Policy and Strategy which is due for publication in the coming months.
Customizing solar suitability maps
IWMI then joined forces with additional solar manufacturing and distribution companies to demonstrate how the maps and tools can be customized and incorporated into sales zoning and marketing strategies.
Map customization is initiated by consulting with companies on their needs and identifying important drivers for these companies and their products. Often, consultations involve detailed data on market profiles, pump sale hubs and other key socioeconomic indicators for the region of interest. These indicators are then incorporated into a revised mapping framework to identify suitable areas.
For example, with SolarWorks in Mozambique, IWMI identified information on current customers using their solar home systems, wireless networks and areas of electrification as important drivers and included these in the framework. In Ethiopia, IWMI worked with TechnoServe and SunCulture, refining the groundwater depth, surface water and population datasets to account for the pump types sold by these companies.
"By adapting the tool to our specific requirements, we were able to generate maps and data that our Ethiopian distributors can use to make better and more informed sales and marketing decisions," said Hack Stiernblad, Director of Business Development at SunCulture. "We see a big need for the same maps and data in all our markets and are exploring options for future collaboration with IWMI in other parts of Africa."
Interest is growing fast. Through ILSSI, USAID has awarded US$ 750,000 to two companies to help them strengthen their solar supply chains. This includes developing affordable financing mechanisms, a lack of which prevents many smallholders, particularly women and resource-poor farmers, from adopting irrigation technologies.
One of these companies, Rensys, is using the maps to target 1,137 Ethiopian households in three regions where it is setting up financing and distribution centers. In northern Nigeria, a US$ 700 million investment by the World Bank will use the maps to gauge the feasibility of groundwater development.
The maps make the potential payoff clear and visible. In Ethiopia, for example, they show that for an 80% probability threshold, between 120,000 and 300,000 households could make good, sustainable use of solar irrigation. In Ghana, some 18,000-34,000 households could benefit, depending on pump type and sources of water. As more companies integrate the maps into their growth strategies, similar potential in other countries is likely to emerge.
Thrive blog is a space for independent thought and aims to stimulate discussion among sustainable agriculture researchers and the public. Blogs are facilitated by the CGIAR Research Program on Water, Land and Ecosystems (WLE) but reflect the opinions and information of the authors only and not necessarily those of WLE and its donors or partners.