Emissions Reporting and Reductions

Today our emissions are lower thanks to a combination of renewable energy, energy efficiency and power plant modernization efforts that include the retirement of older, less efficient coal units . Since 2005, we have reduced emissions of nitrogen oxides and sulfur dioxide by nearly 60 percent from the generating plants we own. We also are on track to surpass our goal for reducing carbon dioxide emissions 20 percent by 2020 from 2005 levels, with current projections indicating a 30 percent reduction companywide. Our clean energy strategy allows us to focus on those initiatives that produce the greatest benefits at the best price and positions us to meet future environmental regulations. Through this approach, we are meeting the many diverse—if not competing—interests of the people we serve by offering customers innovative solutions, keeping energy prices competitive, modernizing our infrastructure, investing in local economies and improving the environment.

CO2 Emissions Reporting and Third-Party Assurance

The CO2 emissions charts in this report show CO2 emissions from electricity produced at Xcel Energy generating plants and purchased from other suppliers. A system emission rate is included for each year. It provides the pounds of CO2 emissions produced for each megawatt-hour of electricity generated or supplied. Xcel Energy’s projected emission reductions are based on our most current energy forecasts.

We have provided only CO2, not other greenhouse gases, such as methane and nitrous oxide. These latter two emissions comprise less than 0.5 percent of total greenhouse gas emissions (CO2 equivalent) from electricity generation. Emissions reported here include biogenic CO2 from biomass power generation, as well as fossil CO2 emissions. However, biogenic CO2 is effectively carbon neutral, since compared to fossil fuels, the CO2 released from biomass combustion is part of a relatively short-term cycling of CO2 between ecosystems and the atmosphere.

Electricity production is Xcel Energy’s most significant source of emissions. We consistently report emissions associated with electricity production in short tons and in pounds per megawatt-hour in our annual form 10-K and Corporate Responsibility Report. This allows users of these reports to follow our company’s emissions trend.

More comprehensive reporting of our greenhouse gas emissions is provided in the GRI Index for this report. See indicators G4-EN15, G4-EN16 and G4-EN17 for Xcel Energy’s Scope 1, 2 and 3 greenhouse gas emissions.

Xcel Energy publicly reports annual CO2 emissions, as well as other greenhouse gases, through a number of different reporting programs, including The Climate Registry, The Carbon Disclosure Project and the U.S. Environmental Protection Agency’s mandatory greenhouse gas reporting rule. These programs each use a unique reporting protocol and may represent emissions differently. While reporting protocols and formats vary, the information we report comes from the same data sources.


Xcel Energy uses methodology that the U.S. Environmental Protection Agency established for reporting greenhouse gas emissions. We follow The Climate Registry’s protocol for greenhouse gas reporting and use The Climate Registry’s comprehensive and electric utility specific protocols. The Climate Registry bases its protocols on both the World Resources Institute (WRI) standards and the ISO 14000 standards on environmental management.

Third-party assurance and verification

The Climate Registry (TCR) is a nonprofit organization established to provide consistent and transparent standards for calculating, verifying and reporting greenhouse gas emissions into a single registry for North America. Xcel Energy recognizes the value and importance of using a formal emissions protocol and completing third-party verification for emissions reporting. We joined TCR as a founding member in 2007, and have since worked to third-party verify and register all of our CO2 emissions going back to 2005. To date, verification and registration is complete for Xcel Energy’s emissions in 2005, 2006, 2008, 2010 and 2011. We anticipate emissions for 2007 and 2009 will be verified and registered in 2015, and the process for verifying 2012 and 2013 emissions is underway.

To learn more about greenhouse gas reporting methodology and third-party assurance for our emissions, go online to The Climate Registry, the U.S. EPA greenhouse gas mandatory greenhouse gas reporting, the WRI protocol and ISO 14000.

Emission reductions

We have a number of retirement, efficiency and emission control projects that are underway or were completed this past year which will reduce emissions and modernize our facilities.

Efficiency, Control and Retirement Projects for 2014
Location Project Description Completion Date
Pawnee Clean Air-Clean Jobs emission control project: Installation of a lime-spray dryer and selective catalytic reduction to reduce SO2 and NOx 2014 (complete)
Hayden Clean Air-Clean Jobs emission control project: Installation of selective catalytic reduction on Units 1 and 2 to reduce NOx 2015 (Unit 1) 2016 (Unit 2)
Cherokee Unit 3 Retire Cherokee Unit 3 in 2015 2015
Texas / New Mexico
Tolk Unit 2 Low-NOx burner and separated over-fire air equipment to reduce NOx emissions about 30 percent. 2014 (complete)
Harrington 1-3 and Tolk 1-2 Installation of activated carbon injection systems for achieving the goal to reduce mercury emissions by 90 percent. 2014 (complete)
Upper Midwest
Sherco Units 1 and 2 Emission control upgrades: Sparger project for additional SO2 reductions, as well as tuning and installation of combustion controls and coal mill improvements for additional NOx reductions 2014 (complete)
Sherco Units 1 and 2 Installation of activated carbon injection (ACI) systems for mercury emission control with a goal of 90 percent reduction 2014 (complete)
Bayfront 1 and 2 Installation of fabric filters for particulate control and activated carbon injection for mercury control 2014 (complete)
Black Dog Units 3 and 4 Retire Black Dog Unites 3 and 4 in second quarter 2015 2015
Bayfront Unit 5 Bayfront Unit 5 will cease coal operations in 2015 2015

Clean Air-Clean Jobs

Xcel Energy worked with a coalition of policymakers and legislators to support the passage of Colorado’s Clean Air-Clean Jobs Act in 2010. Under the legislation, we were directed to propose and implement a comprehensive plan for reducing emissions of nitrogen oxides (NOx) by at least 80 percent from 900 megawatts of coal-fueled generation.



Methane emissions from Xcel Energy’s natural gas distribution system make up less than 1 percent of the company’s total greenhouse gas emissions, most of which are attributed to processes associated with electricity production. Nevertheless, we have worked to cost effectively prevent methane emissions through a combination of proactive system improvements and other efforts implemented as part of our voluntary participation in the U.S. Environmental Protection Agency’s (EPA) Natural Gas STAR program.

In 2014, we reported methane emissions from our natural gas distribution system to be approximately 498 million cubic feet. Emissions were reported under the EPA’s Greenhouse Gas Reporting Program, based on factors that the EPA provides to calculate emissions. Since Xcel Energy became a Natural Gas STAR Partner in 2008, we have reduced the company’s natural gas emissions by a total of 274 million cubic feet—enough natural gas to fuel about 2,100 homes for a year.

Xcel Energy’s methane emission reduction efforts include:

  • Replacing the cast iron pipe and unprotected steel pipe on our system, originally installed 50 to 100 years ago. In fall 2014, Xcel Energy completed replacing all 880 miles of cast iron in Colorado and Minnesota.
  • Using pressure reductions and other methods to reduce methane emissions during pipeline maintenance and repairs.
  • Increasing efforts to prevent dig-ins and other damage to our systems. Our damage prevention program ranks in the top decile of utilities across the nation.
  • Replacing high-bleed controllers on our distribution and high-pressure pipelines. We are currently working to replace the high-bleed controllers in our processing plants and are considering new programs to modernize the high-bleed controllers at our storage fields and compressor stations to reducing emissions at these facilities.

Read more about environmental considerations with natural gas and find information on our natural gas system improvements.

Leading Environmental Commitment