Solar tiles installed in Yemen

“For many in Yemen, especially for farmers, solar power has been a lifeline,” says Matt Leonard, who specializes in microfinance with IFC. “The key now is to scale up its use.” Yemen has long been the poorest country in the Middle East and North Africa, but a conflict that broke out in 2014 has pushed the country to the brink.

Rassam paid about 50 million Yemeni rials (around $90,000 based on the unofficial market exchange rate) for his system, which is considered large by local standards. The average cost of an array is around $10,000. Rassam financed the solar panels with a loan from Al Kuraimi Islamic Bank, one of the country's largest private lenders.

The migration to solar power is part of what researchers say is an energy revolution in the country of 28 million, where the electric grid has been decimated by fighting. More than 50 percent of Yemeni households rely on the sun as their main source of energy, and solar arrays power everything from shops to schools to hospitals.

Farmer Mohamed Ahmad Sid El Rassam can attest to those benefits. He built a solar-powered water pump on his land in the region of Beni Hocheich. The setup chopped his diesel use by more than 85 percent, saving him 17 million Yemeni rials ($68,000) a year.

Across Yemen, a growing number of farmers are turning to solar power to irrigate their fields, a shift that comes as the country tries to stave off what the United Nations warns is an impending famine.

But a collapsing power grid—only 10 percent of Yemenis have access to central electricity—means that many farmers in Yemen's arid hinterland rely on diesel generators to power wells. Along with belching out greenhouse gases, farmers say the generators are expensive to run.