Over one-third of the electricity we generated in 2014 was from carbon-free sources, including nuclear, hydro, wind and solar. Over 25% of our generation was from natural gas, which emits about half as much carbon dioxide as coal when used for electric generation. Duke Energy Renewables sells the electricity and/or RECs it generates to its customers.

Duke Energy has a diverse, increasingly clean generation portfolio.
Fuels consumed for U.S. electric generation
Since 2008, use of coal and oil as generation fuels has significantly decreased. These have been replaced primarily by natural gas, mostly because it became a relatively less expensive fuel and we added natural gas generation capacity.
Water withdrawn and consumed
Water withdrawn is the total volume removed from a water source, such as a lake or a river. Because of the once-through cooling systems on many of our coal-fired and nuclear plants, about 98 percent of this water is returned to the source and available for other uses. Water consumed is the amount of water removed for use and not returned to the source.
Emissions from generation
Emissions levels and intensities depend on many factors, including generation diversity and efficiency, demand for electricity, weather, fuel availability and prices, and emission controls deployed. Since 2005, our U.S. carbon dioxide (CO2) emissions decreased by 19%, sulfur dioxide (SO2) emissions decreased by 85% and nitrogen oxides (NOx) emissions decreased by 64%. Reasons for these decreases include the addition of pollution control equipment, decreased coal generation, increased natural gas generation, and replacement of higher-emitting plants. There is currently no demonstrated commercially available technology to control CO2 emissions from fossil-fueled generation.

U.S. Toxic Release Inventory (TRI)
Duke Energy's TRI releases for 2014 were down 71 percent from 2007, primarily due to the significant investments we've made in environmental controls for our power plants.
Waste
We are on track to increase the percentage of solid waste that is recycled from 69% in 2013 to 80% in 2018. (This goal excludes Duke Energy International and Duke Energy Renewables.)
Reportable oil spills
Oil spills include releases of lubricating oil from generating stations, leaks from transformers, or damage caused by weather or by third parties (typically because of auto accidents).
Environmental regulatory citations
Fines/penalties were relatively large in 2013 because of the November 2013 settlement agreement addressing golden eagle fatalities at wind power facilities. See the “Migratory Bird Settlement Agreement” article in the 2013 Sustainability Report.