Environmental Indicators

Management Approach

We constantly look for ways to improve and grow our company while reducing our impact on the environment.

2016 Mercury Air Emissions with blue background









Weight or volume of materials


Most high-volume materials are purchased by length, reel, pole, transformer, case, truckload or other measure with no consistent relationship to weight or volume. See G4-EN3 for fuel quantities. 



Materials used that are recycled content

It is not possible to precisely determine how much of the material we use to provide electric and natural gas service comes from recycled sources. A portion of steel, aluminum, other metals and plastics may come from recycled sources, and we actively pursue recycling of these materials when their useful life has been reached. Nearly all fuel used is virgin material, because sufficient volumes of recycled fuels are not available.





Energy Consumption

Most of the energy we use is from fuels. See the Fuels Consumed for U.S. Electric Generation table

Another significant energy use is electricity for the buildings we occupy. In 2018 Duke Energy consumed approximately 179 gigawatt-hours of electricity in its commercial buildings.


Indirect energy consumption


We do not centrally track these data. Indirect energy consumption is very small relative to direct energy consumption from fuels to generate electricity.


Energy consumption outside of Duke Energy

We track the amount of energy we supply to customers, and have many initiatives to help them save energy.

In our "Our Sustainability Plan And Goals" we have a goal to achieve a cumulative reduction in customer energy consumption of 15,000 gigawatt-hours (equivalent to the annual usage of 1.25 million homes), and in 2019 updated it to surpass this goal by 25%, by 2020. We also have a goal to achieve a cumulative reduction in peak demand of 6,000 megawatts (MW) (equivalent to ten 600-MW power plants) by 2020. Click Customers in the Plan for an update.


Energy Intensity and Reduction


2018 fossil fuel consumed is approximately 375 million MWh.

MWh electricity produced, from our 2018 Sustainability Report, was 224,609 thousand MWh.

The calculated Energy Intensity (electricity produced / fossil energy used) was:
0.58 in 2013
0.62 in 2018

(2013 is the base year for our reporting of this G4 indicator.)


Energy Efficiency

In the electric utility industry context, energy efficiency is pertinent to both generation efficiency, which we report in GRI economic indicator EU11, and in use of electricity by customers, which we report in G4-EN4, and here.

Energy efficiency programs vary by state and we provide information for each state on our website.


Commentary on Water Management 
 See Water Quality Initiatives.



Water Withdrawal

See Water Withdrawn and Consumed in the Environmental Performance Metrics section of our Sustainability Report.



Water sources and habitats affected by withdrawals

Water for various aspects of electric generation is drawn from surface and underground sources. Large volume withdrawals are regulated by state or federal permit conditions that are designed to prevent adverse impacts on aquatic species and communities.



Water recycled or reused

Our largest, most material use of water is for electric generation cooling. Approximately 98 percent of the water withdrawn is returned to the source after once-through cooling. The returned water is available for other uses. 

Our largest recycling of water is through use of closed-loop cooling systems, and we do not record the volume of water recycled through these systems. See Water Withdrawn and Consumed in the Environmental Performance Metrics section of our Sustainability Report.

In 2018, water consumption totaled approximately 374 gallons per net MWh electricity produced.





Land in and adjacent to protected areas and areas of high biological diversity value

We help protect the biological diversity of lands we own or manage. Specific permits and licenses regulate our operations in some of these areas. See several examples.


Impacts on high biodiversity value areas, including transmission line corridors

Environmental analyses performed during planning stages of new facilities are used to identify potential areas of high biodiversity value. If such areas are found, permit conditions are designed to prevent or minimize impacts.

Programs to manage biodiversity  Duke Energy is a strong partner with wildlife and biodiversity management organizations. We also provide examples of how we are protecting eagles, and protecting habitat.


Habitats Protected or Restored


We manage and protect various habitats surrounding our facilities and along our rights of way.


Special species habitats

At times, species of special concern to state and/or federal agencies are found on company land. We work closely with agency personnel to protect these species. See G4-EN12.

Emissions, Effluents, and Waste



Greenhouse gas (GHG) emissions


See Emissions from Generation and our response to the Carbon Disclosure Project.


Other relevant indirect GHG emissions

We do not track or report our indirect emissions. They are a very small percentage relative to our direct emissions.



Initiatives to reduce GHG emissions, and reductions achieved

See Global Climate Change, our 2017 Climate Report to Shareholders, and an update on our carbon emissions reduction goals in our Sustainability Plan and Goals (click Operations for an update.) 


Ozone depleting emissions, by weight

We do not centrally track these data. Each facility is responsible for its own compliance with recordkeeping requirements.


NOx, SO2 & other significant air emissions by type and weight

See the Emissions from Electric Generation and Toxic Release Inventory (TRI) tables in the Environmental Performance Metrics section of our Sustainability Report.

Mercury emissions to air are provided in this table. From 2006 to 2018 mercury emissions were reduced by 94%.

Mercury Air Emissions


Total water discharges

Given our combinations of once-through cooling systems, recirculating systems and other water discharges, we do not record a total quantity.


Total weight of waste by type and disposal method

See the Waste table in the Environmental Performance Metrics section of our Sustainability Report.



Total number and volume of significant spills


See the Reportable Oil Spills table in the Environmental Performance Metrics section of our Sustainability Report.


Transported hazardous waste


See the Waste table in the Environmental Performance Metrics section of our Sustainability Report.

In 2018, hazardous waste generation totaled approximately 0.0025 pounds per net MWh electricity produced.



Water discharge impacts


Discharges are to rivers and lakes by regulatory permits. Those permits and our operating practices are designed to protect the environment and aquatic species. 

Products and Services




Environmental impact mitigation


We offer a number of programs to help residential and business customers be more energy efficient and we also protect sensitive habitats on our property.



Percentage of product that is recycled

Electricity and natural gas cannot be recycled in the usual sense. We recycled over 82,000 tons of solid wastes resulting from our operations in 2018. See the Waste table in the Environmental Performance Metrics section of our Sustainability Report.





Incidents and fines for environmental noncompliance


See the Environmental Regulatory Citations table in the Environmental Performance Metrics section of our Sustainability Report.





Environmental protection expenditures


We do not centrally track this broad range of expenditures. However, please see our Sustainability Report for more information on recent and planned expenditures to reduce emissions.

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