Recovered Energy

What recovered energy is:

  • Recovered energy is energy that would otherwise go to waste. It is also called waste heat energy, recovered heat, heat recovery or recovered energy generation.
  • Recovered energy generation (REG), is a process of capturing hot exhaust to drive a turbine and create electricity.

Recovered energy in North Dakota:

Heat Recovery Unit Goes Into Operation: Learn more about how REG works in North Dakota.Video courtesy of Basin Electric Power Cooperative.
  • North Dakota has the first recovered energy generation (REG) system that uses a natural gas pipeline, the Northern Border Pipeline, which runs about 1,400 miles through several midwestern states and into Canada.
  • The pipeline angles across the southwestern part of North Dakota.
  • When natural gas needs to be moved thousands of miles, the safest method of transportation is through pipelines.
  •  In order to transport natural gas through a pipeline, it must be compressed (its molecules packed tightly together).
    • Compression reduces its volume and increases its pressure so that it can flow easily through the pipe.
      • In order to ensure that the natural gas in the pipeline remains pressurized, compression is done at compressor stations located at 40 to 100 mile intervals along the pipeline.
        • At each compressor station, the natural gas is compressed by a special turbine.
          • Hot exhaust is created in this process.
  • Recovered Energy Generation: Ask the Expert
  • A company linked to Ormat Technologies developed a way to use waste exhaust from Northern Border Pipeline to generate electricity. 
    • The temperature of the exhaust at the compressor stations ranges from 850⁰ to 950⁰ F.
      • The exhaust is recovered by using heat exchangers.
        • A heat exchanger is a device that transfers heat from one medium to another.
      • The recovered heat is used to vaporize a fluid, which spins a turbine connected to a generator to produce electricity. Visit the Bismarck State College Animation Tool to see how Recovered Energy Generation Works.
  • Basin Electric, a North Dakota utilities company, purchases the REG-produced electricity generated at three compressor stations in North Dakota: Manning, St. Anthony, and Zeeland.
    • Each site produces 5.5 megawatts of electricity for a total of 16.5 megawatts.
  • Montana-Dakota Utilities (MDU) owns an REG system near Glen Ullin, North Dakota.
    • This heat-recovery generation station generates 5.3 megawatts of electricity.
One megawatt of electricity can provide power to approximately 800 homes.