The Earth Institute at Columbia University harnesses scientific research, education, and practical solutions to create a more sustainable world through innovation and critical thinking. Earth Institute has partnered with The MDG Center West and Central Africa (WCA)—an organization established to assist WCA countries to develop and implement operational strategies aimed at achieving the Millennium Development Goals.
In Senegal, farmers currently use two practices for watering crops: the labor intensive method of flood irrigation with wells and buckets, or the cost- and energy-intensive method of using diesel-powered motor pumps. Neither of these options is ideal in a country with immense solar resources that can be harnessed and used to transform irrigation practices in the country and region.
Earth Institute’s solution will enable a small group of farmers to use a central solar energy unit to power multiple alternate current (AC) pumps for irrigation. The proposed solution takes advantage of the benefits of solar without the high costs associated with direct current (DC) powered pumps and battery storage. This power will be accessed by farmers with prepaid electricity cards issued by a micro-utility, and sold through local vendors who will benefit from a small commission. Recognizing that a major obstacle to technology adoption is financing, a tariff-based financing model will allow customers to cover their appliance loans in small payments added into their micro-utility bills.
This innovation allows farmers, even with small land holdings and/or little access to capital, to benefit from irrigation. Access to Pay-as-you- go irrigation in this part of coastal Senegal has shown farmers how they could potentially grow two crops in a year and generate an annual revenue of as much as $5000/ha.
By the end of the Powering Agriculture Award in March 2016, Earth Institute had installed three shared battery-less solar PV pumping systems in Potou, Senegal. The three shared systems serve 21 farms, including a farm run by a women’s cooperative, and are now seeing maximum utilization. Farmers have experienced a 29% average increase in agricultural production, and resulted in 24 tons of CO2 equivalent emissions avoided from not having to use diesel pumps. Eight persons have been trained on how to service the pumping systems. The project is now seeking partnerships for scaling up, adoption and local maintenance contracts.