Environmental stewardship

Rainbow energy center dragline

Our top priority

Promoting sustainable, reliable energy

At Rainbow Energy Center, we care deeply about the environment.  We are mindful of how our operations could impact the environment and surrounding communities where we live and work, which is why conserving our natural resources and environmental stewardship is a top priority for us.  Through the use of energy efficient and pollution prevention processes, we are constantly pushing the limits of innovative technologies to reduce our footprint on the environment so future generations have the same opportunities that we have today.

Our Environmental Policy

Environmental Policy

Rainbow Energy Center safely provides affordable and reliable energy while putting environmental stewardship, conservation, and compliance at the forefront of our operations and business. We strive to find the best technologies to reduce our impact on the environment for our communities and future generations through efficient pollution prevention processes.

Rainbow Energy Center commits to utilize the following principles to guide our decision-making process and improve our environment:

  • Maximize efficient operations, innovation, and technology to minimize our environmental impacts during all stages of our businesses.
  • Conduct our operations and business in accordance with all applicable environmental, health and safety laws, regulations, while providing the training and resources necessary for our employees to support this effort.
  • Conserve our resources through environmental stewardship, pollution prevention, waste minimization, recycling, and reuse.
Fly ash recycled
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99.5% of the fly ash produced in generation is recycled for cement replacement.


Invested in tech
$ 0 B

Utilities in ND have invested more than $2 billion in technology to protect the environment and spend about $100M annually to operate it.

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Coal Creek Station is responsible for 600+ jobs in North Dakota.



Annual Impact
$ 0 B

Coal Creek Station provides a $1.5 billion estimated annual impact to the state of North Dakota.


We use advancing technologies and effective business solutions to drive a sustainable future.

Enhancing the power of Lignite

Plant Efficiencies

Using DryFine™ Technology to Be Cleaner and More Efficient

Coal burns. Water doesn’t. Softer coals, such as lignite, have a higher water content than other types of coal. Reducing the amount of water in lignite through a drying process has several advantages:

We saw these benefits and were determined to make drying and refining, or as we call it ‘DryFining,’ a key practice at Rainbow Energy Center. We now DryFine all the coal used at Coal Creek Station to make it cleaner and more efficient. We’re enhancing the power of lignite by using a product that would otherwise be wasted: the waste heat generated by Coal Creek Station.

How DryFining Works

The lignite is dried and refined using DryFine™ technology to reduce moisture from the coal before it enters the furnace, thereby increasing burn efficiency and reducing emissions. The process uses excess heat from the plant and removes sulfur dioxide (SO2), mercury, nitrogen oxide (NOx), and carbon dioxide (CO2).

The Benefits We've Seen

Key Benefits from DryFining have been:

  • Reduce the moisture of lignite
  • Increase the energy content of lignite 
  • Increase power plant efficiency
  • Reduce maintenance and related expenses
  • Reduce emissions of sulfur dioxide, nitrogen oxides, mercury, and carbon dioxide

Collecting and Selling Fly Ash

Electrostatic precipitators collect 99.5% of the fly ash produced. This fly ash is marketed and sold to ready-mix concrete companies in the Upper Midwest where it is used as a cement replacement. Fly ash sales also reduce greenhouse gas emissions as making cement is energy intensive (about one ton for each ton of fly ash used to replace cement mix).

Supporting Farmers By Selling Steam

Excess steam from Coal Creek Station is also sold to the neighboring ethanol plant for use in its production of ethanol, corn oil, and distiller grains. Local farmers have an expanded market for the sale of corn, which is used by the ethanol plant and blended with gasoline and transportation fuel.

“Emission reduction has been and remains a strategic, continuous process improvement.”

Plant Manager