The Massachusetts Institute of Technology (MIT) researchers have recently released a report evaluating a range of solar pump technologies and business models available in India for irrigation and salt mining to better understand which technologies can best fit farmers’ needs.

Groundwater pumps are a critical technology in India, especially for small scale farmers who depend on them for irrigating crops during dry seasons. With the lack of a reliable electrical grid connection, and the high price and variable supply of diesel fuel, solar-powered pumps have great potential to meet farmers’ needs while reducing costs and better preserving natural resources.

The report details the study design and findings of the latest experimental evaluation implemented by the Comprehensive Initiative on Technology Evaluation (CITE), a program supported by the U.S. Agency for International Development (USAID) and led by a multidisciplinary team of faculty, staff, and students at MIT.

Despite the tremendous potential for solar pumps to fill a technological need, there is little information available to consumers about what works best for their needs and a wide range of products available for selection.

“There’s a lot of potential for these technologies to make a difference, but there is a large variance in the cost and performance of these pumps, and lot of confusion in finding the right-sized pump for your application,” said Jennifer Green, CITE sustainability research lead and MIT Sociotechnical Systems Research Center research scientist.

To conduct the evaluation, MIT researchers worked closely with the Technology Exchange Lab in Cambridge, Massachusetts, as well as the Gujarat, India-based Self-Employed Women’s Association, a trade union that organizes women in India’s informal economy toward full employment and is currently piloting use of solar pumps in their programs.

Researchers tested the technical performance of small solar pump systems in the workshop at MIT D-Lab, and tested larger solar pump systems in communities in India where they were in active use. This allowed for more rigorous, controlled lab testing as well as a more real-life, grounded look at how systems operated in the environment in which they would be deployed. Researchers also used a complex systems modeling technique to examine how the pumps impacted the social, economic, and environmental conditions around them, and how different government policies might impact these conditions at a macro level.

In the lab, MIT researchers procured and tested five pumps — the Falcon FCM 115, the Harbor Freight, the Kirloskar SKDS116++, the Rotomag MBP30, and the Shakti SMP1200-20-30. Lab tests on flow rate, priming ease, and overall efficiency demonstrated that two of the lower-cost pumps — the Falcon and the Rotomag — performed the best, and the most expensive pump — the Shakti — performed poorly. MIT researchers also studied pump usage, installing remote sensors in panels and pumps being used in Gujarat, India to ensure that the pumps were being used consistently over the course of a day, and operating properly.

As solar pumps are often too expensive for small-scale farmers, CITE also conducted a business case analysis to understand what financing mechanisms might make solar pump technology more affordable for these critical end users.

“The cost of solar pumps is still prohibitively high for individual farmers to buy them straight out,” added Green. “It will be critical to ensure financing mechanisms are accessible to these users. Coupling solar pump systems with well-thought out government policies and other technologies for minimizing water use is the best approach to optimizing the food-water-energy nexus.”

Image credit: MIT