General Electric (GE) and PHG Energy of Nashville, Tennessee have developed a project together that will generate electricity from waste material. The hybrid device, built from three main parts, uses a Clean Cycle Heat-to-power generator developed by GE.
The heat-to-energy generator used in the system is already in use around the world, converting waste heat into energy which can be delivered to homes and businesses. Each of these biomass generators can produce enough electricity to supply the electrical demands of around 50 average homes. They can operate using a wide variety of fuels, assisting areas where wood or other traditional fuels may be in short supply, or be too expensive to be practical.
Combing GE's heat-to-power generator with a gasifier developed by PHG Energy and an off-the-shelf heat exchanger, the companies hope that their new design will be able to supply electricity to cities, using sewage and other waste as a fuel source. Heat that is not used to help generate electricity can be applied to drying out the waste water.
"The project is simple and elegant in its straightforward design, capable of operating on multiple and varied waste streams, and offers operating costs far below existing waste-to-energy generation systems in the marketplace," Tom Stanzione, president of PHG Energy, said.
The process begins with the conversion of biomass, including wood chips, into a clean-burning gas. This gas is then burned through a process known as the Organic Rankine Cycle (ORC).
Research into the new hybrid electrical generators is taking place in Gleason, TN, where six of the machines are currently in operation, operating kilns. Excess electricity generated by the tests will be sold to the Tennessee Valley Authority, who supplies electricity to the area.
A similar operation is underway in Covington, Tennessee, where city leaders are currently in negotiations with PHG Energy to assist them in converting wood and sewage waste into electricity. Not only will such power reduce the city's reliance on fossil fuels, but it will also save the city hundreds of thousands of dollars a year in landfill and disposal fees. Developing this system in Covington is expected to save 450 tons of carbon dioxide a year from being released into the atmosphere.
"Innovation such as this, involving our equipment, is exciting and opens doors to many applications," Brad Garner, President of GE's Heat Recovery Solutions Division, said.
The next stage of development will be the production of one to five megawatt (MW) models, which will require gasifiers capable of producing eight times the output of current models