Spotlight on Solar Water Pumps
Situated at the heart of the water-food-energy nexus, solar water pumps can play a critical role in building climate resilience and propelling sustainable development. This snapshot quantifies the climate, social, and economic benefits that could be realized with modern irrigation access across 11 countries: Ethiopia, India, Kenya, Malawi, Mozambique, Nigeria, Rwanda, Sierra Leone, Uganda, Zambia, and Zimbabwe. It finds that if existing irrigation access gaps for smallholder farmers in these countries were closed, 410 Mt of CO2 per year could be avoided and 98 million people would benefit from increased food security.
The impact of climate change on agricultural systems will have far-reaching consequences on livelihoods and food security. Within the agriculture sector, smallholder farmers1 are highly vulnerable to climate change. Many rely on rain-fed agriculture, cultivate small areas of land, and lack access to the technical or financial resources needed to develop more climate-resilient agriculture practices.2,3,4,5 Situated at the heart of the water-food-energy nexus, the solar water pump can play a critical role in building climate resilience and propelling sustainable development.
Using the Efficiency for Access Impact Assessment Framework for Solar Water Pumps, we estimate that over 43 million households in 11 countries across sub-Saharan Africa and South Asia are unable to access a solar water pump but could make use of one (see Section 2.2 in Net Zero Heroes: Scaling Efficient Appliances for Climate Change Mitigation, Adaptation & Resilience). The majority of these households are composed of smallholder farmers who practice agriculture on a small scale. For these farmers, the social, economic, and resilience benefits of expanded access are significant.
We estimate that if the irrigation access gap (2.1 billion people) were closed exclusively by solar pumps (see Section 2.2 of the paper), 98 million people would benefit from increased food security; 23 million from improved access to water, sanitation, and hygiene (WASH), and 13 million people—over 1 million of them women—would experience the time-saving benefits from reduced drudgery and manual labor (Table below). Beyond that, we estimate that over 15 million households would experience yield increases greater than 30% and that over 850,000 jobs could be created within the agriculture sector. Access to solar water pumps would also avoid future demand increases in fossil fuels.
If the entire access gap for solar water pumps were closed by solar pumps instead of diesel pumps, farmers would save over $100 billion USD in fuel costs and avoid emitting 410 Mt of CO2 per year. Collectively, the benefits from access to a solar water pump will help them adapt to numerous adverse environmental changes tapping into new sources of groundwater and building resilience to periods of social and economic hardship through reduced drudgery and greater farm productivity. Expanded use of solar water pumps, however, must be balanced with effective water management policies to protect against groundwater overdrafts. New access to mechanized water pumping in India and Nepal indicates that water pumping without sustainable water management can lower the water table and increase the use of energy to pump water at deeper levels.6 Developing and implementing sustainable water management practices can help ensure that water sources are not depleted unsustainably.
Table 1: Socioeconomic and environmental impacts of universal access to solar water pumps in 11 countries
| Total (millions) | Sub-Saharan Africa (millions) | India (millions) | |
|---|---|---|---|
| Number of people with improved access to energy services due to their solar water pump | 106 | 501 | 55 |
| Number of people reporting annual agricultural yields increases of at least 30% | 15 | 7 | 8 |
| Number of people who perceive improved food security and nutrition from solar water pump ownership | 98 | 47 | 51 |
| Number of people benefiting from improved access to water, and enhanced sanitation and hygiene (WASH) | 23 | 11 | 12 |
| Number of people experiencing time saving benefits from reduced manual labor | 13 | 6 | 7 |
| Avoided fuel costs ($USD million)* | 104,000 | 50,000 | 54,000 |
| CO2 emissions avoided (Mt)* | 410 | 197 | 213 |
Despite the large potential climate, social, and economic benefits, the solar solar water pump market remains small and vastly underpenetrated. Over 15,000 solar water pumps were sold in the second half of 2022, a 63% increase in sales volumes compared to the first half of the same year. This growth in sales, however, pales in comparison to the market potential. In 2019, Efficiency for Access estimated that, with rising household income and decreasing product prices, the market for solar water pumps in sub-Saharan Africa could expand to as many as 2.8 million households and a value of USD 1.6 billion by 2030.7
Affordability remains a large challenge in making solar water pumps more accessible to smallholder farmers. Only 0.1% of smallholder farmers in Sub-Saharan Africa can afford a pump.8 Consumer financing is important to bridge the affordability gap, but mechanisms like PAYGo financing are more challenging to implement as pumps are generally used seasonally and can require other agricultural inputs and training for farmers to use successfully.
0. Smallholder farmers are small-scale farmers who manage areas varying from less than one hectare to 10 hectares.
1. John F. Morton, “The Impact of Climate Change on Smallholder and Subsistence Agriculture,” Proceedings of the National Academy of Sciences 104, no. 50 (December 11, 2007): 19680–85, https://doi.org/10.1073/pnas.0701855104.
2. Avery S. Cohn et al., “Smallholder Agriculture and Climate Change,” Annual Review of Environment and Resources 42, no. 1 (October 17, 2017): 347–75, https://doi.org/10.1146/annurev-environ-102016-060946.
3. Margaret Buck Holland et al., “Mapping Adaptive Capacity and Smallholder Agriculture: Applying Expert Knowledge at the Landscape Scale,” Climatic Change 141, no. 1 (March 2017): 139–53, https://doi.org/10.1007/s10584-016-1810-2.
4. Portia Adade Williams et al., “A Systematic Review of How Vulnerability of Smallholder Agricultural Systems to Changing Climate Is Assessed in Africa,” Environmental Research Letters 13, no. 10 (October 2018): 103004, https://doi.org/10.1088/1748-9326/aae026.
5. Ram Bastakoti, Manita Raut, and Bhesh Raj Thapa, “Groundwater Governance and Adoption of Solar-Powered Irrigation Pumps Experiences from the Eastern Gangetic Plains,” Water Knowledge Note (World Bank Group, 2019), https://openknowledge.worldbank.org/server/api/core/bitstreams/d7eb3522-9205-56b8-bcfe-d10e923af024/content.
6. Efficiency for Access, “Solar Water Pump Outlook 2019: Global Trends and Market Opportunities” (Efficiency for Access Coalition, 2019).
7. Efficiency for Access, “Solar Water Pump Outlook 2019: Global Trends and Market Opportunities.”