Environmental Performance Metrics

Data table showing electricity generated in 2011.

2011 Electricity Generated*

	52.5%	Coal
	26.1%	Nuclear
	10.4%	Natural gas / oil
	9.5%	Conventional hydro
	1.9%	Wind / solar

* Pumped-storage hydro, which totaled (0.4%), consumes more energy than it produces.

Almost 40 percent of the electricity we generated in 2011 was from carbon-free sources, including nuclear, hydro, wind and solar.

Data table showing generation capacity in 2011.

2011 Generation Capacity*

	40.4%	Coal
	28.1%	Natural gas / oil
	13.0%	Nuclear
	10.3%	Conventional hydro
	2.7%	Wind / solar

* Pumped-storage hydro, which totaled 5.4%, consumes more energy than it produces.

Our diverse generation portfolio helps us generate electricity that is affordable, reliable and increasingly clean.

Data table showing fuels consumed to generate electricity.

Fuels consumed for U.S. electric generation
Compared to 2010, coal consumption decreased and natural gas consumption increased in 2011, mostly because natural gas became a relatively less expensive fuel.

Data table showing withdrawn and consumed.

Water withdrawn and consumed
Water withdrawn is the total volume removed from a water source, such as a lake or a river. Due to 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.

Data table showing emissions from generation.

Emissions from generation
Emission levels and intensities depend on many factors, including generation diversity and efficiency, demand for electricity, weather, fuel availability and prices, and emissions controls deployed. Carbon dioxide (CO₂), sulfur dioxide (SO₂) and nitrogen oxides (NOx) emissions decreased in 2011 from 2010 due to decreased generation (resulting from lower electricity demand), decreased coal generation and increased natural gas generation. We have invested approximately $5 billion over the past decade to significantly reduce SO₂ and NOx emissions from our coal fleet. As a result, we have reduced U.S. SO₂ emissions by almost 76 percent and NOx by 52 percent since 2006. Our fleet modernization strategy will help us further reduce emissions.

Data table showing U.S. sulphur dioxide and nitrogen oxides emissions.

Data table showing U.S. toxic release inventory.

U.S. Toxic Release Inventory (TRI)
Duke Energy's TRI releases for 2011 are down 64 percent from 2006 and 17 percent from 2010. Air emissions alone decreased 20 percent from 2010 to 2011. This long-term trend is due to significant investments we've made in environmental controls at our power plants, and reduced coal-fired generation. We are retiring older coal-fired units or using them less, as we bring newer, more efficient and environmentally advanced units on line.

Data table showing U.S. on-road and off-road vehicle emissions and fuel consumed.

U.S. on-road and off-road vehicle fleet emissions and fuel consumed
We have a goal to reduce nitrogen oxides, volatile organic compounds, particulate matter and carbon monoxide emissions from our on-road and off-road vehicle fleet by 35 percent by 2012 compared to 2006. From 2006 to 2011, emissions have been reduced by almost 31 percent, and we are on track to meet our goal.

Data table showing accelerated main replacement program.

Accelerated Main Replacement Program
In 2000, the Accelerated Main Replacement Program (AMRP) was launched on Duke Energy’s natural gas distribution system in Ohio and Kentucky to prevent leaks requiring repair and to improve safety, performance and reliability. The program accelerates replacement of approximately 1,400 miles of cast iron and bare steel pipe, some in service since 1873. The AMRP is complete in Kentucky and more than 80 percent complete in Ohio. We are on track to meet our target of reducing repaired leaks by 20 percent by 2012 compared to 2007. Reducing leaks decreases the release of natural gas, which is mostly methane, a greenhouse gas approximately 20 times more potent than CO₂.

Data table showing waste.

Waste
We have a goal to increase the percentage of U.S. solid waste that is recycled from 52 percent in 2008 to 62 percent by 2012. Our nuclear plants also have a goal to reduce by 25 percent the amount of
low-level radioactive waste (Class B and C) they generate by 2012, compared to the 2002 through 2006 average of 1,552 cubic feet. In 2011, we exceeded both of these goals.

Data table showing U.S. electricity consumed.

U.S. electricity consumed
We have a goal to reduce electricity consumption at 13 of our largest commercial buildings by 10 percent by 2012, compared to the 2005 through 2007 average. In 2011, we exceeded this goal.

Data table showing reportable oil spills.

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 due to auto accidents).

Data table showing environmental regulatory citations.

Environmental regulatory citations
No fines were associated with 10 of the 12 citations in 2011. The 2007 total fines/penalties figure includes proposed fines of approximately US$29 million assessed by the Brazil State Environmental Agency of Parana (IAP) and approximately US$250,000 by the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) for alleged violations related to reforestation. We continue to contest these violations.