As the sun lazes toward the horizon off the coast of Perico Island in El Salvador, Marvin Arturo Martinez hurries his fishing boat back to shore. By nightfall, Martinez and his neighbors will reach for flashlights and boxes of matches, shuttered indoors until the morning. In a town that has never been touched by an electrical grid, residents spend half of each day in candlelight or darkness.

“We have to do everything we can during the day, as fast as possible, before the night comes,” Arturo says, “and then darkness, again.”

One in ten Central Americans live without electricity, hindering productivity, education, and economic growth. Across El Salvador’s mountainous border, many Hondurans face a similar plight. Antonia Salgado of El Guayabo, Honduras, is fifty years old and has never lived with electricity. “Who knows?” she says, “Maybe we’ll die in the dark.”

To tackle this problem, Tetra Tech partnered with the U.S. Agency for International Development (USAID) and the governments of Guatemala, Honduras, and El Salvador through the Regional Clean Energy Initiative (RCEI), which has helped to develop the region’s energy markets and reduce energy costs. From 2012 to 2017, this initiative supported projects across the region, electrifying dark city streets and isolated rural communities alike.

Thanks to the partnership in Central America, a new solar grid installed on Perico Island has given Martinez and his community access to reliable, clean power. The community’s school, which now has electricity, has working computers for its students.

In central El Salvador, the city of Zacatecoluca was provided with new LED streetlights for a five mile stretch of streets. These new streetlamps affordably illuminate dark areas of the city, making it a safer place for its 40,000 inhabitants.

Reliable, affordable power sources can make a huge impact on a community. When communities have access to electricity, health risks are lower, children have more time to study, and workers can remain productive past sundown.

By providing better access to vital services like electricity, partnerships like this one help to strengthen and stabilize an important region in America’s backyard, improving conditions and reducing the risk of population migration into neighboring countries. As Congress turns its attention to next year’s International Affairs Budget, stories like Martinez’s are increasingly poignant. America’s development programs require full funding—to ensure no one gets left in the dark.