In response to our nation's growing need for baseload electricity generation, Duke Energy is pursuing the use of biopower (“biomass to electricity”) as a renewable energy resource.
According to the U.S. Department of Energy, biopower is renewable energy made from any organic material from plants or animals. Wood energy is derived both from direct use of harvested wood as a fuel, and from wood waste streams. Animal wastes, agricultural “energy crops” and municipal discards are other fuels for biopower.
Advantages of biopower include its ability to dispatch electricity on demand and provide baseload-like capacity, much like fossil-fueled plants. In addition, many federal and state environmental agencies consider biopower to be carbon-neutral.
Duke Energy is employing a variety of strategies to make cost-effective investments in biopower in its retail states and comply with renewable energy mandates. In North Carolina, for example, the company is:
- Testing the co-firing of wood with fossil fuel at select existing facilities, and exploring the potential to retrofit units at other sites to generate electricity by burning only wood fuel.
- Supplying customers with power from landfill methane gas projects.
- Signing contracts to purchase electricity generated from biomass and municipal solid waste.
- Making plans 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.
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.
Poultry Power USA
North Carolina has a renewable energy portfolio standard mandating that certain amounts of statewide electricity sales must come from poultry and swine wastes. To help meet this requirement, Progress Energy Carolinas, a Duke Energy company, signed a contract with Poultry Power USA to purchase the output of a 60-megawatt poultry waste-to-biogas power plant to be built in Duplin County, N.C.
- 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.
- Micro-turbine with biofuels
We have 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.