The evolution of SF1

Posted in — Lessons Learned > Technology
September 23, 2017
(Photo by Bimala Colavito/iDE)

iDE continuously listens to the needs and aspiration of the farmer and continuously works to introduce better options through the market.

With funding first from the Bill & Melinda Gates Foundation, REEEP, and National Geographic, and later from USAID’s Powering Agriculture Grand Energy Challenge for Development, iDE and the PRACTICA Foundation developed a PV-driven Sunflower Pump (now known as the SF1). iDE led testing on over 70 pumps, focusing on the product’s durability, farmers' perceptions, and user experience with the product. Feedback received from hundreds of farmers in Nepal, Zambia, and Honduras has been used by the developers to modify the pump’s design. In the last three years, the pump has undergone five major design iterations to improve its performance, durability, and price point. Today, the private company Futurepump, a social enterprise that emerged from the PRACTICA Foundation and iDE partnership, is manufacturing and distributing the SF1 pump worldwide through its Indian manufacturing facility.

Why the SF1?

Smallholder farmers need affordable, energy-efficient pumps for irrigation. Compared to petrol-powered pumps used by smallholders on the market, which generally use less than 20 percent of the energy to move water, the SF1 is highly efficient, using 80 percent of the energy. The SF1 uses a piston design as opposed to a centrifugal design. This reduces the cost, increasing affordability, improving efficiency, simplifies manufacturing, improving the pumps ability to handle water sources with more suspended solids, and lessening the maintenance required. Although the cost to purchase the SF1 may be two- to three-times the purchase price of a internal combustion pump, the FAO estimates that the irrigating operating costs of a petrol pump are US$500 annually per hectare, while this cost is nonexistent with a solar pump. Finally, plant science indicates that plant growth occurs most during periods of bright sunlight. Since solar pumps operate best in the same conditions, pump performance and crop watering needs are strongly correlated.

Designing a successful product for smallholders is not an overnight process. The following timeline illustrates how designers need to iterate continuously to meet the needs and aspirations of the target market.

The SF1 Solar Pump Development Timeline:

  1. 2008 - 2011

    The Bill & Melinda Gates Foundation

    Designed by inventor Gert Jan of PRACTICA, this early prototype was the original “Sunflower” solar steam pump. It used a piston pump that ran on a steam engine. A reflective 1.8m parabolic dish concentrated solar energy to a boiler that produced steam, which was converted to mechanical energy to run the piston pump. At the time, the price of PV was too cost-prohibitive to be a viable solar energy source.


      Field tested in Ethiopia

  2. 2011 - 2013


    Renewable Energy and Energy Efficiency Partnership (REEEP) funding focused on scaling and market research.


      Field tested in Ethiopia

  3. Oct 2013 - 2016

    USAID’s Powering Ag

    The Sunflower design ramped up during this period with consistent support from USAID producing several design iterations over a 3-year period. The early model prioritized extreme affordability.


      Field tested in Zambia, Nepal, Honduras, Cambodia

  4. 2013

    National Geographic Society

    National Geographic Society funded development of real-time sensors on the Sunflower. The sensors track pump health and performance and allow remote control access to the pump’s power source. The latter ability opens up several pay-as-you-go options for vendors and markets, to minimize upfront payment requirements.


      Field tested in Nepal

  5. 2014


    Futurepump changed the name from Sunflower to SF1, indicating “surface flow”, making room for a line of pumps to come that may include a deep lift pump. They manufacture and distribute from their plant in India. As of mid 2017, 1,300 portable SF1 solar-powered pumps have been built and sold in 29 countries.

Future Iterations

While improvements continue to be made with the manufacturing of each batch, there is still a need to make the solar pump more versatile, robust, and affordable to reach a wider range of customer and pumping needs. For example:

  • The pump is limited currently to applications where the water level is less than seven meters deep. Although the current SF1 has a large market, it excludes a growing number of farmers whose access to water is deeper than seven meters and whose water table is dropping due to changing weather patterns. A deep lift pump has been developed but still needs significant testing and investment to bring it to a mature product.
  • The SF1 was designed to meet the needs of smallholder farmers capable of irrigating up to 2,000 square meters of vegetables. Higher yield pumps are better options for farmers with larger plots and greater water requirements.

With the appropriate support in design and research, these challenges could be overcome to better serve the needs of farmers.

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