Valley Power Plant was constructed along the Menomonee River in Milwaukee in 1968. Designed to generate 280 megawatts of electricity for the grid and supply steam for more than 300 customers in downtown Milwaukee, the plant fulfills a critical role — not only producing electricity and steam, but also providing voltage support for the downtown area.
Cogeneration — combined heat and power — is one of the most efficient methods of producing electricity and thermal energy from a single fuel source. At Valley Power Plant, electricity is generated by burning coal in a furnace to create heat. In a boiler, the heat converts water into steam, which drives a turbine that drives a generator to make electricity. Cogeneration occurs when a portion of the steam used to generate electricity is extracted from the turbine and distributed to Milwaukee downtown customers and businesses for space and water heating, laundry, sterilization processes, food processing and other purposes.
Heat and electricity generated at Valley Power Plant are reliable and efficient alternatives to heat provided by individual, on-site boilers. Steam is delivered through an underground distribution network that includes more than 18,000 linear feet of steam tunnels. The system is operated through an automatic system that controls the flow of steam and pressure on the system from the plant’s control room. This control room was the first on We Energies’ system constructed to handle all of the major plant operations and the district steam system.
We have a long-standing and proven track record of investing in a reliable and balanced energy portfolio that reduces our environmental impact and improves air quality in southeast Wisconsin. Since 2000, our system-wide emissions of sulfur dioxide, nitrogen oxide, particulate matter and mercury have been reduced by more than 80 percent.
Over the past decade, Valley Power Plant emissions have decreased significantly, including a 65 percent reduction in sulfur dioxide emissions. In October 2010, the U.S. Environmental Protection Agency commented on the air quality improvements, noting that the community monitor closest to the Valley plant – the 16th Street Community Health Center monitor – has the lowest monitored ozone levels in southeast Wisconsin. Converting the plant’s fuel source from coal to natural gas will further enhance its environmental performance.
In August 2012, we announced plans to convert Valley Power Plant’s fuel source from coal to natural gas to help reduce operating costs and enhance environmental performance. Estimates indicate the conversion will result in about a 1 percent decrease in electric rates and up to a 7-8 percent increase in steam rates.
We filed applications on April 26, 2013, with the Public Service Commission of Wisconsin (PSCW) for approval to convert the fuel source to natural gas and upgrade the natural gas infrastructure near the facility. On March 17, 2014, the PSCW issued a Certificate of Authority (PDF) approving the project.
The plant's electric capacity is expected to remain 280 megawatts. The current cost estimate of conversion is approximately $70 million.
Switching fuel sources requires converting the existing boilers from coal to natural gas. Boiler conversion entails removing the existing coal burning equipment, installing natural gas piping and burners, and modifying the combustion controls. The project also requires modifying or replacing auxiliary systems, equipment and plant controls.
Conversion of Unit 1 from coal to natural gas was completed successfully Nov. 5, 2014. Unit 2 will be converted to natural gas this year.
Valley Power Plant’s steam services network covers approximately 1.8 square miles of downtown Milwaukee, extending from Mitchell Street on the south to West Vliet Street on the north, and from Lake Michigan west to 19th Street. View map