Interstate finishes construction of pipeline to new Marshalltown power plant

Interstate Power and Light told the Iowa Utilities Board that a gas pipeline lateral to its new Marshalltown power plant is structurally complete and should be loaded with first gas in November of this year.

The board in November 2013 had approved this pipeline project. Interstate Power and Light (IPL) constructed the Marshalltown Generating Station (MGS) Lateral pipeline to supply natural gas from an interconnection with Northern Border Pipeline Co. in Marshall County, Iowa, to the power plant’s gas yard in Marshall County. The pipeline was designed to deliver up to 171,600 Mcf/day. The pipeline is approximately 13.13 miles in length.

The 20-inch MGS pipeline was hydrostatically tested in two sections. The first section of pipe, Iowa River south to the power plant gas yard, was tested to a pressure of 1825 psig on June 30. On Sept. 17, the pipeline construction was complete. The pipeline is tentatively scheduled to be purged and packed with natural gas in late November 2015.

Said IPL parent Alliant Energy (NYSE: LNT) about the power plant project in its Aug. 6 quarterly Form 10-Q report: “IPL is currently constructing Marshalltown, an approximate 650 MW natural gas-fired combined-cycle [electricity generating unit]. Construction began in 2014 and is expected to be completed in 2017.”

Said the board about the pipeline project in a November 2013 decision document: “The proposed pipeline will transport natural gas from a connection with a Northern Border Pipeline Company pipeline in northeastern Marshall County to IPL’s proposed Marshalltown Generating Station (MGS) and to IPL’s existing Sutherland Generating Station (SGS) in Marshalltown, Iowa. The MGS will improve IPL’s fleet fuel diversity and reduce IPL’s dependency on market energy; provide additional voltage support and enhance reliability for the regional electric transmission grid; and use natural gas in the production of power, which produces fewer emissions and reduces the air quality impact when compared to alternate fuels. IPL plans to convert the existing SGS combustion turbine units from fuel-oil to natural gas. The proposed pipeline will also connect to the Marshalltown distribution system. This alternate source of natural gas for the Marshalltown gas system may produce lower gas costs and will improve system reliability.”

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.