As gas prices across the globe soar higher and higher, both political instability and biological limits provide a compelling impetus for countries to explore viable alternative energy sources. As part of a plan to generate 10 percent of its electricity from alternative energy sources by 2020, Ghana is turning its most problematic output, poop, into power.
With the support of Ghana’s renewable energy czar, Kwabena Out-Danquah, the country will build its first raw sewage-guzzling biodiesel plant. This serves the dual purpose of creating a viable green energy source and reducing the amount of raw sewage in the country, which poses a significant health threat.
Each day, open sewers sweep one thousand tons of fecal sludge (poo) into the ocean off the capital, Accra. This polluting, ocean-top brown slick is visible on Google Earth. Outside the city of Kumasi, roughly 100 trucks dump tens of thousands of liters of raw septic tank sewage into what used to be a small pond.
With the new plant, one truck a day from Kumasi will dump its payload into a massive vat that will skim lipids – fat – off the top, which will be turned into biodiesel. The septic sludge will be pumped into the plant and cooked into biodiesel which can be used to power generators and turbines.
Biodiesel is a hot commodity for renewable energy seekers. Since everyone poops and human waste is just that – waste – it is much cheaper and readily available than other biodiesel sources like algae and soybean oil. According to a recent report from Environmental Science & Technology, one liter of extracted, poop-derived lipids costs a whopping $0.03, while soybean lipids can cost around $0.80.
As with other emerging alternative fuel possibilities, cost and engineering barriers still exist. The biofuel from the sewage plant may cost about $7 per gallon to start. Although, given the uncertain future of petroleum-based fuel and continuous improvements in technology that can improve efficiencies this may end up being a viable, affordable alternative for other countries to model.
The Ghanaian company, Waste Enterprisers is heading the project, flush with $1.5 million in backing funds from the Bill & Melinda Gates Foundation. If the pilot plant is successful and they can lower costs, Waste Enterprisers intends to sell the fuel to commercial customers who are also bound by the 10 percent goal and build four more plants in Accra.
I’d pay for poo power – would you?
(photo by David Sckrabulis: a jet engine running on biofuel at the Naval Air Systems Command Aircraft Test and Evaluation Facility, Patuxent River, MD.)
