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Coal & Carbon Intensity

Coal and Carbon Intensity

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Why do we say that Xcel has one of the most carbon intensive supplies in the country?

  • Xcel Energy operates in Colorado as Public Service Company of Colorado, or PSCo. PSCo is a wholly owned subsidiary of Xcel.
  • Carbon intensity is the average carbon dioxide released  from an energy source relative to amount of energy produced, e.g. pounds per megawatt-hour of energy produced.
  • Xcel in the top 40 of the 100 largest U.S. electric power producers, ranked by how carbon-intense its electric supply is. Xcel therefore has one the most (top 50 percent) carbon intensive energy supplies in the country.
  • Additionally, PSCo has the highest carbon intensity of Xcel's subsidiaries.
  • View an in-depth letter from Sept. 11, 2014, pdf regarding how we determine carbon intensity.

How much coal generation does Xcel currently have in Colorado?

In 2016, PSCo’s resource mix (in MWh generated) was 46 percent coal, 25 percent natural gas, 23 percent wind, 4 percent hydro, and 2 percent solar (utility-scale and rooftop).PSCo estimates that their resource mix will change to 41 percent coal, 18 percent natural gas, 34 percent wind, and 6 percent solar and 1 percent hydro by 2021.

What is "carbon intensity?"

Carbon intensity is the amount of carbon by weight emitted per unit of energy consumed ( EIA definition ). It is sometimes measured in pounds of carbon per megawatt-hour (lbs/MWh).

How is the carbon intensity for Boulder's energy supply calculated?

Historically, the City of Boulder has used eGRID data (regional carbon intensity information produced by the EPA) to calculate Xcel’s carbon intensity, because it is updated regularly based on data sets supplied directly by utilities to EIA and FERC. The eGRID factor for the Rocky Mountain region, which includes Colorado and parts of Kansas and Wyoming, is consistently the highest or second-highest carbon intensity in lbs/MWh in the country.

The city also looks to data provided by Xcel Energy directly and analyzed by other entities. Xcel’s 2013 Corporate Responsibility Report shows that PSCo is the most carbon-intense of Xcel’s subsidiaries, at 1,516 lbs/MWh generated. Over 80 percent of the 27 million short tons of carbon emissions that PSCo produced in 2013 came from owned generation—including 2,500 MW of coal generating units.

A recently released Ceres/National Resources Defense Council benchmarking report places Xcel in the top 40 of the 100 largest U.S. electric power producers, ranked by how carbon-intense the electric supply is. In contrast, Sacramento Municipal Utility District and NextEra Energy (which has developed numerous Colorado wind farms) have less than half of Xcel’s carbon intensity.

M.J. Bradley & Associates, Benchmarking Air Emissions of the 100 Largest Electric Power Producers in the United States (2014), pdf.

Contact Us

Address Phone Email Executive Director

1101 Arapahoe Ave.

Boulder, CO 80302


[email protected]

Steve Catanach

[email protected]