Due to a change in a U.S. Environmental Protection Agency air rule, the Northern States Power unit of Xcel Energy (NYSE: XEL) has been able to push back the construction of $18.5m of new air controls at the Bay Front power plant.
Northern States Power-Wisconsin (NSPW) told the Public Service Commission of Wisconsin in an April 30 quarterly update that the change is under EPA’s Industrial Boiler Maximum Achievable Control Technology (MACT) rule. The commission had approved the Bay Front project, which includes a baghouse and activated carbon injection systems, in December 2012.
“On December 20, 2012, the EPA announced modifications to the Industrial Boiler MACT that, among other things, increased the allowable mercury emissions and extended the compliance deadline to 3 years after the new requirements are published in the Federal Register,” the updated noted. “Since the modified requirements were published in the Federal Register on January 31, 2013 the new compliance deadline is January 31, 2016. The project in-service date has been extended to December 16, 2014 to take advantage of the extended compliance deadline.
Construction at Bay Front has not started. NSPW anticipates mobilizing to the site on May 20.
The Bay Front plant is located on the shore of Chequamegon Bay, Lake Superior. Currently, three boilers feed steam into a combined steam header system that can support three turbine-generator sets. These boilers, known as boilers number 1, 2, and 5, currently burn fuels including coal, waste wood, railroad ties, tire-derived fuel, and natural gas to produce steam that drive the three turbine-generator sets (identified as numbers 4, 5, and 6) to produce electricity.
Of the three existing turbine-generator sets, #4 has a capacity of 22 MW and came into service in 1949, #5 has a capacity of 22 MW and came into service in 1952, and #6 has a capacity of 30 MW and was placed in service in 1957. NSPW told the commission that the current expected life of the plant is five to nine years.
NSPW plans to construct new baghouse and ACI facilities to reduce particulate matter (PM) and mercury emissions from boilers #1 and #2 at the facility. NSPW has said it has no plans to install additional air control equipment on boiler number 5 because it intends to burn only natural gas in that boiler after Jan. 1, 2015, in order to comply with the Wisconsin mercury reduction rule.