Platte River Power Authority to Slash Emissions: Replacing Coal with Natural Gas Turbine in 2030

Carbon Neutral Group would like to express our firm support for the Platte River Power Authorities’ plan to retire its coal-fired Rawhide Unit-1 sixteen years ahead of schedule and replace it with a new aero-derivative natural gas turbine of roughly the same capacity.

The Federal Energy Information Agency (EIA) states that burning coal to produce electricity emits 2.3 pounds of CO2 per kilowatt hour (KWH) while burning natural gas emits just 0.97 lbs. resulting in a 58% reduction in emissions. Because the aero-derivative natural gas turbine preferred by PRPA is 43% efficient as opposed to the 33% efficient simple-cycle gas turbines currently used at Rawhide to meet peak demand, the emissions reductions will be even greater, or about 68% cleaner than burning coal, a giant leap (for mankind) in the right direction.

Renewables and beneficial electrification such as heat pumps and electric vehicles (EVs) are considered the best ways to reduce emissions, but heat pump emissions are as dependent on the “resource mix” as the coefficient of performance (COP) of the heat pump itself, Likewise, EV CO2 emission reductions (vs gasoline) are directly tied to a utility’s electricity resource mix.

In the case of heat pumps, as it stands today, only Xcel Energy and Colorado Springs Utilities offer electricity that is sufficiently clean enough to achieve emission reductions w/cold-climate heat pumps versus a high-efficiency natural gas furnace. Both utilities’ emissions of 1 lb. of CO2 per KWH are achieved with an even mix of coal, natural gas, and renewables (1/3 each) resulting in a 12% reduction in CO2 emissions for a cold-climate heat pump versus the 95% efficient natural gas furnace.

Other utilities such as Platte River Power Authority, Poudre Valley REA, and Black Hills Energy, with their heavy reliance on coal (+50%), have CO2 emissions of 1.4 – 1.5 lbs. of CO2 per KWH which are  40-50% higher than Xcel/CO-Springs. In these cases, a cold-climate heat pump operating on the Front Range of Colorado results in 19% higher emissions than a high-efficiency natural gas furnace.              

In the case of electric vehicles versus internal combustion engines (ICE) powered by gasoline, again, it’s the electricity resource mix that determines the relative reduction in emissions. Gas-powered cars emit 20 pounds of CO2 per gallon of gas burned to travel 25 – 30 miles on average. The Tesla Model Y for example (#1 selling car in the world in 2023) burns 10 KWHs of electricity in 30 miles, resulting in just 10 lbs. of CO2 emissions from Xcel’s grid, and 14.5 lbs. of CO2 when charged by coal-dominant utilities.  EVs are 25% cleaner with a 50% coal resource mix and 50% cleaner when powered by an even mix of coal, natural gas, and renewables.

The PRPA/Rawhide plant managers, engineers, and maintenance staff are considered world-class in the utility industry, earning the 2023 National Plant of the Year award for innovations in efficiency, reliability, and pollution control. Plant engineers have even developed methods of throttling down the coal-powered turbine to as low as 30% of full capacity when energy demand is lower and when ample renewable energy is available, a breakthrough achievement.    

When PRPA replaces the coal-fired generator with an aero-derivative natural gas turbine and with renewables supplying 40% of our electricity, CO2 emissions will be just 0.5 lbs. per KWH. As a result, cold-climate heat pumps will produce 60% lower CO2 emissions than natural gas furnaces, and electric vehicles will produce 65% less CO2 emissions than gasoline-powered cars.

PRPA’s plan to replace coal with natural gas will result in an astounding reduction in emissions, reduce energy costs, and maintain the rock-solid reliability we may have come to take for granted.

Note: All calculations referenced in this article are available upon request.

Thank You, Michael Truitt

Finance, George Mason University, 96’

Xcel Energy Residential Energy Auditor

Efficiency Works Business Service Provider

RESNET Energy-Star Certified Rater, 2015 – Present

NATE-Trained HVAC Design & Commissioning,

HVAC-VerifiedTM & Airflow UpgradeTM (Pat. Pend.)

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