Case Study: We Energies' Valley Power Plant Uses SmartProcess™ Combustion Optimizer To Sustain 10% NOx Reductions

In response to evolving ground-level ozone standards in the United States, We Energies began a proactive, comprehensive strategy to prepare for new environmental regulations by reducing nitrogen oxide (NOx) emissions throughout its generation fleet. We Energies investigated solutions that evaluated NOx reduction against dollars per ton removal. Valley Power Plant was selected as the test site for the NOx reduction technology because of its close proximity to downtown Milwaukee and its challenging NOx control process. Low NOx burners were installed at the Valley Station, which provided decreased NOx emissions, but additional reductions in NOx were desired in order to ensure exceeding regulatory limits. As a cycling plant, Valley is on automatic dispatch and seldom base-loaded, so whatever technology was chosen, it needed to be reliable and robust enough to handle fast changing conditions, as well as provide We Energies with enough NOx reductions to meet environmental limits throughout the wide operating range of the plant.

Results:

• 99.9% system availability
  
• 93.7% system utilization for over 7 years
  
• 10% sustained average NOx reduction since 2000
  
• 18% decrease in excess oxygen
  
• 20% reduction in desuperheater spray flow