It takes one mother seven hours to bathe her family. She leaves her Cairo apartment, bucket in hand, and walks to the neighborhood water standpipe. Returning, bucket balanced atop her head, she climbs three flights of stairs, lights the stove, and waits for the water to warm. Bucket after bucket, trip after trip, hour after hour.

Thomas Taha Rassam "T.H." Culhane has a better idea.

His nongovernmental organization, Solar C.³I.T.I.E.S., works with residents of Cairo’s poorest neighborhoods to install rooftop solar water heaters. "They generate 200 liters of hot water and 200 liters of cold water for each household every day," Culhane explains. "And since the technology is completely CO2 free, it contributes nothing to global warming. If people don’t have access to enough water, it becomes a serious health issue. And when women spend all their time tending stoves to heat water, they how can they go to school or get ahead?" Culhane’s grasp of these daily challenges is personal; he and his wife moved to a slum apartment themselves to gain firsthand experience.

He stresses that his organization is not merely a solar power provider, but an idea generator. "We realize the value of collective intelligence. These neighborhoods are filled with welders, plumbers, carpenters, and glassworkers. We bring capital and plans; they bring talent and creativity. We build these systems together from scratch." And while environmentally friendly solar heaters do reduce carbon emissions, he insists that’s a byproduct, not his agenda: "We’re not being idealistic; we’re out to provide solutions. Solar energy plays a principal role in our work because it makes practical, perfect sense."

In fact, Culhane’s work on the rooftops of Cairo began under the treetops in tropical forests. During rain forest ecology fieldwork with the Dayak of Borneo and the Maya Itza of Guatemala’s jungle villages, he witnessed a culture that used every part of the environment to survive and thrive. "It inspired me to rethink urban living along those same ecological principles." Surprisingly, it was in a city of 20 million that he encountered the rain forest ethic again.

Cairo’s Zabaleen people (literally translated as "garbage people") have collected and recycled the city’s waste by hand for decades. "We’re taught that garbage is garbage," Culhane notes, "but the Zabaleen view everything around them as useful for something. They’re a model of industrial ecology. They already were using solar energy to dry plastics they recycled and resold. So could they use the sun for other things? I went in with the idea of solar water heaters—technology that can be built entirely from recycled materials, with your own two hands, at minimal expense. People were so enthusiastic! They had considered solar heaters, but a pre-manufactured unit cost the equivalent of a year’s salary."

Instead, Culhane offered basic design plans, while local craftsmen added improvements and sourced materials. "It’s been a really humbling experience," he observes. "One family‘s goat kept jumping up and breaking the heater’s glass panels. We elevated the unit out of harm’s way by building a brick wall. They immediately realized the new space could be used as a cool, shaded ‘goat house,’ which would keep the flock from dying during blazing summer months."

The incident epitomizes a fundamental Culhane belief: Poor communities are rich with possibilities and innovative ideas. "The poor don’t need our pity; they need a chance to help themselves," he says. "I categorically do not believe in categories. The poor aren’t a class of weak victims; they’re millions of creative individuals."

With Culhane's help, more than 30 solar tanks now dot the rooftops of the Zabaleen’s primarily Coptic Christian community, as well as Darb Al-Ahmar, an Islamic Cairo neighborhood. "I divide my time between the two, working to bring them together," Culhane notes. (Hence the name Solar C.³I.T.I.E.S: Connecting Community Catalysts Integrating Technologies for Industrial Ecology Systems.) "I knew if they could actually meet one another and connect on a project to solve common problems, they would overcome their differences. They immediately began sharing and building on each other’s expertise. Now we’re using the strengths of both Christianity and Islam to fight a common enemy: environmental degradation."