Environmental Performance Metrics
Nearly 35% of the electricity we generated in 2013 was from carbon-free sources, including nuclear, hydro, wind and solar. And more than 25% was from natural gas, which emits about half as much carbon dioxide as coal.
Duke Energy has a diverse, increasingly clean generation portfolio.
Compared to 2008, coal consumption decreased by about one-third, and oil consumption decreased to less than one-fifth of 2008 volumes. Natural gas consumption tripled in that same time period, mostly because natural gas became a relatively less expensive fuel and we added natural gas generation capacity.
Water withdrawn is the total volume removed from a water source, such as a lake or a river. Because of 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.
Emission 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. CO2 emissions decreased by 20%, sulfur dioxide (SO2) emissions decreased by 84% and nitrogen oxides (NOx) emissions decreased by 63%. These decreases are primarily because of decreased coal generation, increased natural gas generation, and replacement of higher-emitting plants. In addition, Duke Energy and Progress Energy have invested more than $7 billion in SO2 and NOx emission controls since 1999. (There is currently no demonstrated, commercially available technology to control CO2 emissions.) Our current forecasts suggest upward pressure on our CO2 emissions in the years ahead. This will challenge our ability to meet our 2020 emission reduction goals.
Duke Energy’s TRI releases for 2012 were down 68 percent from 2007, primarily due to the significant investments we’ve made in environmental controls for our power plants. (Data for 2013 will be available in August 2014.)
A new U.S. solid waste recycling goal for the merged company has been established. We will increase our solid waste recycling from 69% in 2013 to 80% by 2018.
Oil spills include releases of lubricating oil from generating stations, leaks from transformers, or damage caused by weather or by third parties (typically due to auto accidents).
The increased fines/penalties from 2012 to 2013 were due to the November 2013 settlement agreement addressing golden eagle fatalities at wind power facilities. See the “Migratory Bird Settlement Agreement” article in this report.