Solar-powered irrigation systems improve diet and income in rural sub-Saharan Africa, Stanford study finds

Solar-powered irrigation systems improve diet and income in rural sub-Saharan Africa, Stanford study finds

Sun-powered pumps installed in remote villages in Benin provide a cost-effective way of delivering irrigation water, particularly during the long dry season.

"There was an overwhelming sense of pride in the new system by teachers, children and women participating in the farmer groups," said Jennifer Burney, a postdoctoral scholar with the Program on Food Security and the Environment at Stanford.

Solar-powered drip irrigation systems significantly enhance household incomes and nutritional intake of villagers in arid sub-Saharan Africa, according to a new Stanford University study to be published in the Proceedings of the National Academy of Sciences (PNAS). The study found that solar-powered pumps installed in remote villages in the West African nation of Benin provide a cost-effective way of delivering much-needed irrigation water, particularly during the long dry season. The results are scheduled to be published the week of Jan. 4 in the online edition of PNAS.

"Our case study on women's farming groups in rural Benin revealed solar-powered drip irrigation – a clean, cost-competitive technology – significantly improved nutrition and food security as well as household incomes in one year," said lead author Jennifer Burney, a postdoctoral scholar with the Program on Food Security and the Environment at Stanford.

"Solar-powered drip irrigation systems break seasonal rainfall dependence, which typically limits farmers to a three- to six-month growing season, and support the production of diversified, high-value crops in rural Africa," Burney added.

She and her co-authors noted that much of sub-Saharan Africa's rural population is considered "food insecure," surviving on less than $1 per person per day. "And whereas most are engaged in agricultural production as their main livelihood, they still spend 50 to 80 percent of their income on food, and are often net consumers of food," they wrote.

Benin pilot project

In 2007, with support from Stanford's Woods Institute for the Environment, Burney and her colleagues partnered with the nonprofit Solar Electric Light Fund (SELF) on a pilot irrigation project in rural Benin. SELF financed and led the installation of three solar-powered drip irrigation systems in two villages in Benin's Kalalé district. Each system is used by a local women's agricultural group, which typically consists of 30 to 35 women who share the maintenance costs of the new irrigation technology.

Marshall Burke

A woman cleans a solar panel that powers the drip irrigation system in a rural village in Benin.
"In Kalalé, 80 percent of the villagers live on less than $1.25 per day, which is representative of a number of poor, rural communities in Africa," said study co-author Rosamond Naylor, director of the Program on Food Security and the Environment and a professor of environmental Earth system science at Stanford.

In rural Benin, women and girls traditionally are responsible for hauling water by hand, often from very long distances. The solar-powered irrigation systems were designed to free them from hauling water to grow vegetable crops, particularly during the dry season.

To measure the impact of the solar-powered drip irrigation technology, the researchers monitored the agricultural groups using the new irrigation systems, as well as two "control" villages where women continued growing vegetables in traditional hand-watered gardens. Household surveys were conducted at the start of the project in November 2007 and again in November 2008.

Nutrition and income

The results were striking. "In just one year, we saw that photovoltaic drip irrigation systems had important implications for food and nutrition security, as well as household income," Burney said.