Waste Power is Flush With Success

High natural-gas prices, along with the the growing interest in both water quality and renewable energy, are fueling continued efforts to turn animal and human waste into economically viable power sources. Two current utility projects on opposite sides of the U.S./Canada border are focusing on new ways to encourage the capture of manure-based methane (or "biogas") as a generating fuel.

06/01/2004


High natural-gas prices, along with the the growing interest in both water quality and renewable energy, are fueling continued efforts to turn animal and human waste into economically viable power sources. Two current utility projects on opposite sides of the U.S./Canada border are focusing on new ways to encourage the capture of manure-based methane (or "biogas") as a generating fuel. In addition, Pennsylvania researchers have succeeded in generating electricity directly from human waste-water through the use of a bacteria-powered "microbial fuel cell."

Central Vermont Public Service, based in Rutland, Vt., is counting on the support of environmentally conscious consumers in its application to sell a new renewable-energy product dubbed "Cow Power." Similar to other utilities' wind-power initiatives, the plan would allow utility customers to opt to obtain some or all of their electricity from farm-based methane sources, at a $0.04-per-kWh premium. The surcharge would be paid back to participating farmers, to counter the expense of generator installation and to provide an additional income stream.

Similarly, utility planners in the Canadian province of Saskatchewan have initiated a pilot program with area pig farmers. Engineers at Clear Green Biotechnologies Inc. partnered with utility SaskPower to install a methane-digestion project with a 125-kW generating capacity. The design incorporates four microturbines and accompanying heat exchangers. The heat exchangers both partially warm the facility's hog barns and keep the digester's microbes at a comfortable 37

Clear Green Biotechnologies is using this installation to model the manure-management services it plans to offer other area pig farmers.

Meanwhile, scientists at Penn State University are investigating the possibility of waste itself—rather than the methane it releases—as a viable power resource. Researchers have developed a small fuel cell that harnesses the energy released by bacteria as it breaks down organic waste. Bacteria release electrons as they do their work. With the microbial fuel cell, these electrons are passed to an anode and then travel through a wire to a cathode, producing an electrical current. Similar devices have been developed to work with water containing chemicals such as glucose, acetate and lactate, but this is the first to use wastewater skimmed directly from a water-treatment plant.

As presently designed, the fuel cell only produces between 10 and 50 milliwatts of electricity per square meter of electrode surface. However, researchers hope future designs, with greater surface areas and more efficient materials, could aid development of self-powered water-treatment plants.





No comments
Consulting-Specifying Engineer's Product of the Year (POY) contest is the premier award for new products in the HVAC, fire, electrical, and...
Consulting-Specifying Engineer magazine is dedicated to encouraging and recognizing the most talented young individuals...
The MEP Giants program lists the top mechanical, electrical, plumbing, and fire protection engineering firms in the United States.
Combined heat and power; Assessing replacement of electrical systems; Energy codes and lighting; Salary Survey; Fan efficiency
Commissioning lighting control systems; 2016 Commissioning Giants; Design high-efficiency hot water systems for hospitals; Evaluating condensation and condensate
Solving HVAC challenges; Thermal comfort criteria; Liquid-immersion cooling; Specifying VRF systems; 2016 Product of the Year winners
Driving motor efficiency; Preventing Arc Flash in mission critical facilities; Integrating alternative power and existing electrical systems
Putting COPS into context; Designing medium-voltage electrical systems; Planning and designing resilient, efficient data centers; The nine steps of designing generator fuel systems
Designing generator systems; Using online commissioning tools; Selective coordination best practices
As brand protection manager for Eaton’s Electrical Sector, Tom Grace oversees counterfeit awareness...
Amara Rozgus is chief editor and content manager of Consulting-Specifier Engineer magazine.
IEEE power industry experts bring their combined experience in the electrical power industry...
Michael Heinsdorf, P.E., LEED AP, CDT is an Engineering Specification Writer at ARCOM MasterSpec.
click me