Humanitarian Engineering: Zero-Emissions Hydroelectric Power
Dartmouth Humanitarian Engineering (DHE) students traveled to southern Rwanda during the summer of 2012 to install a zero-emissions hydroelectric generating station on the Rugaragara River. Collaborating with e.Quinox, a student group from Imperial College London, the team designed, refined, and built a pico-hydro system to provide enough electricity to charge cell phones and light homes in the villages of Rugote and Nyamirambo.
“The plans originally called for civil works consisting of a weir, settling tank, penstock, kiosk, tailrace, and a gabion wall that could handle water volumes necessary to generate 1 kilowatt of power,” says participant Kevin Francfort ’15. “Later, we scaled these designs up in order to provide our team and our partners the ability to increase our power output to 5 kilowatts in the future.”
The team also designed a way to make the power realistically affordable to local people. They surveyed villagers to find out how much people actually could pay to use the system. Since most people didn’t have enough cash to buy a battery, the team came up with a less-expensive business model: a monthly rental system. Shopkeepers or others who do have money can buy the batteries, charge them from the generator, and rent them out to customers. When the battery needs to be recharged, the customer returns it to the shopkeeper.
“The battery can charge 11 cell phones on one battery charge or power LED lights, which we hand out to all consumers, for two or three hours a day for three or four weeks,” says Asher Mayerson ’15.
By opening day for the system, 60 families had signed up. Shortly after, the customer base rose to 80 families. “We believe that our system is providing electricity to far more than the 80 community members who signed up for our business. It is typical for the batteries that we provide to be used in businesses, which have a multiplier effect on the local economy and benefit many community members not actively renting a battery,” says Francfort. “There are over 300 families living in close proximity to the site—about 2 kilometers or less—many of which are experiencing the benefits of having electricity in their village for the first time. We’re pleased to have been able to improve the lives and opportunities of these people.”
In December, DHE was awarded nearly $15,000 from the U.S. Environmental Protection Agency’s National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet to support ongoing work on the hydropower and battery rental system in Rugote.
In addition to the work in Rwanda, DHE continues to address health and energy needs in Tanzania. Dartmouth students designed a stove that burns the region’s abundant coffee husks instead of scarce wood. “The stove could effectively cook even the most difficult of Tanzanian staple dishes using both coffee husks and sawdust, a versatility we believe will make our stove attractive to a much larger market,” says Nik Ortman ’13. An NGO, Educational Model Organization, and local crafts people will oversee the 10 stoves that DHE gave to villagers, and DHE members will make any needed modifications on their next trip.
DHE also helped two Tanzanian communities produce briquettes of compressed composted cornhusks and charcoal dust for cooking. “Briquetting reduces the amount of smoke and need for firewood,” says Amelia Ritger ’15. Sale of the briquettes can also become a small business. “One group was so excited about the technology that they invested in their own briquette press almost immediately,” says Ritger. In the future, DHE will partner with the NGO Sustainable Harvest to optimize charcoal for use in briquettes and in high-quality fertilizer.
—Kathryn LoConte Lapierre
For more photos, visit our Humanitarian Engineering collection on Flickr.