Biopower

At Duke Energy, we're pursuing the use of biopower (“biomass to electricity”) as a renewable energy resource.

What is biopower?

The U.S. Department of Energy defines biopower as renewable energy that is made from any organic plant or animal material. Wood energy is derived from wood waste streams or by using harvested wood as a fuel. Animal wastes, agricultural “energy crops” and municipal discards are other examples of biopower fuel.

Advantages of biopower

Biopower can deliver electricity on demand and provide baseload-like capacity, much like fossil-fueled plants. Many federal and state environmental agencies consider biopower to be carbon-neutral.

 

What we're doing

We're making cost-effective investments in biopower within our retail states while complying with renewable energy mandates. In North Carolina, for example, the company is:

• Supplying customers with power from landfill methane projects.
• Signing contracts to purchase electricity generated from biomass and municipal solid waste.
• Planning to procure electricity derived from biomass, animal waste and municipal solid waste as stipulated in the state’s Renewable Energy and Energy Efficiency Portfolio Standard.
• Partnering with local research organizations to develop new technologies.

Biofuel projects

We have contracts to purchase more than 300 megawatts (MW) of electricity from various biomass power plants in the Carolinas and Florida. Below are several of our biomass projects:

Wood waste biopower:
48 MW in Craven County, N.C.; 25 MW in Duplin County, N.C.

Municipal solid waste:
144 MW from five plants in Florida; 16.2 MW from two plants in North Carolina

Note: Only a sampling of our projects is represented here. Not all of the listed North Carolina projects count toward the state’s Renewable Energy Portfolio Standard (REPS), since they existed before the introduction of the REPS in 2007. We also have several contracts for biomass power plants under development including, for example, contracts for three 16-MW wood-waste plants to be built in Central Florida.

Research partnerships: biopower inventory and potential

The Florida Energy Office awarded the University of South Florida’s Power Center for Utility Explorations and Progress Energy a $70,000 grant to review the feasibility of generating power using biomass, research issues associated with collection and use of biomass, and assess the biomass sources.

Research partnerships: micro-turbine with biofuels

We've partnered with the University of Florida in a Florida Department of Environmental Protection program to demonstrate the Power, Water Extraction and Refrigeration (PoWER) distributed energy system. This system, patented by the University of Florida, combines a novel semi-closed gas turbine with a vapor absorption refrigeration system in a way that enables several potential system benefits. These benefits include fuel flexibility using bio-derived and conventional fuels, very low emissions, high efficiency, high part-load efficiency and quad-generation capability. The PoWER system demonstration plan also includes a vapor absorption refrigeration system. This system is designed to provide air conditioning in addition to cooling the gas turbine flow at the main compressor inlet. The current project includes plans for grid connection support by our company and exploration of demand-side management strategies using this technology.