Rice hulls are like baby pigeons. They seem to exist only in the abstract. The hard shells protect rice grains during the growing season. But they are long gone when we tuck into a sushi roll. During harvest, they rise in looming mountains of waste. Ingenious farmers have turned them into bricks, fertilizer and even beer. But now they have another option. They can use them to generate renewable electricity for their rice mills.
GE engineers have long explored the use of unusual waste as fuel. They already know how to make electricity from cheese whey, whisky mash, even leftover school lunches. Rice hulls are a step down the same road. Later this year, GE will supply the Cambodian rice mill operator Soma Group with GE’s two massive Waukesha engines that will generate electricity by burning methane from fermented rice chaff. “The Soma Group project is a breakthrough,” says Kenji Uenishi, president of GE Energy for the Asia Pacific region. “GE’s gas engine technology is ideally suited to support agricultural waste-to-value applications in developing countries.”
The Waukesha engines will be manufactured by GE workers in the United States. They will generate a total of 1.5 megawatts of electricity that will power the operations of a Soma rice mill in the Kamphong Cham region of southeastern Cambodia. The mill will also sell surplus electricity, as much 70 percent of output, to the local grid and support Cambodia’s rural electrification program. It will come on-line in 2013.
At the moment, only half of Cambodia’s villages have access to electricity and demand is growing by 25 percent annually. GE’s distributed power generation technology that employs Waukesha and Jenbacher engines is already helping electrify towns and businesses in rapidly developing countries in Asia, Latin America, and Africa.
Soma chose the Waukesha engines over a diesel system because in Cambodia rice husks are a cheap and plentiful fuel. The Cambodian government estimates that it will export 1 million tons of rice in 2013. The exports will create about 400,000 tons of rice husks. Less than four pounds of husks can produce 1 kilowatt hour of electricity, enough to power a 26-watt CFL light bulb for nearly 40 hours.