HYDROPOWER: A team of Dartmouth College Thayer School of Engineering students (working through the school's student-run Humanitarian Engineering Leadership Project, or HELP) designed, built and installed a mini hydroelectric turbine in Rwanda. They hope it will deliver environmentally friendly power to the country's Banda region, which has a population of about 6,000. Image: Image courtesy of Dartmouth's Thayer School of Engineering
As scientists and engineers puzzle over how to inexpensively deliver thin-film photovoltaic solar cells, wave and tidal powered turbines, hydrogen-fueled cars, and other advanced technologies to reduce world dependence on fossil fuels, a team of college engineering students is working on a decidedly lower-tech, though no less difficult, project they hope will bring hydroelectric power to remote areas of the African country of Rwanda.
The group, part of Dartmouth College's Thayer School of Engineering student-run Humanitarian Engineering Leadership Program (HELP), in September set up two hydroelectric turbines powered by a local water source in Banda, a mountainous region at the edge of Nyungwe National Park with a population of around 6,000.
The first site's turbine—prebuilt and taken to Banda by the students—generates enough energy to charge six 12-volt batteries concurrently. "While the total power (310 watts) is relatively low by American standards, its enough to charge up to 30 batteries per day, each of which only needs to be recharged once every two weeks," engineering student Eric Trautmann, 23, wrote in a September 19 blog on the group's Web site. Trautmann, who is pursuing his masters in robotics, is one of 15 Thayer electrical, environmental and mechanical engineering students working on the Rwanda project. Eight of the students—including Trautmann—have traveled to Banda since June to get the turbines up and running, while the other seven helped plan the project, design the turbines, and provide backup support from the U.S.
The second turbine, built from scratch with local parts and labor, has been more troublesome. The turbine's charge controller—used to ensure batteries do not overcharge—has malfunctioned repeatedly, says student Derek Brand, 22, who recently returned from Rwanda after a three-month stay. While in Africa, Brand needed to travel several hours to another village in search of new parts to correct the problem. The turbine is now up and running and producing 300 Watts of energy.
The students plan to, with help from the locals, upgrade the sites over time to improve their output to 1.5 kilowatts, enough meet all of the village's electrical needs and more. But for now, Brand says, increasing power isn't a top priority because the combination of energy produced by both sites is "more than enough to meet the town's demand, at least until we return next summer."
In the meantime, some of the Banda people use the turbine sites to recharge the car batteries that serve as the main power source for their homes (providing the juice they need for lighting and to charge smaller batteries used in cell phones, flashlights and radios). It is not uncommon for a Banda resident to walk dozens of miles over the area's rough terrain with a 40-pound (18-kilogram) battery balanced on his or her head to the nearest town with electricity, sleep the night there, and then walk back home the following day with the recharged battery.