Gas, New Projects, On-Site Power, Retrofits & Upgrades

CAT gas-fired gensets pegged for revamped, fast-start SD plant

Photo courtesy Caterpillar.

On-site power giant Caterpillar will supply gas-fired generator sets for a new 58-MW addition to a quick-response power plant in South Dakota.

NorthWestern Energy has tasked Caterpillar with providing six Cat G20CM34 gensets for the Huron power plant. The utility is planning $86 million in upgrades to the existing gas-fired generating station.

The Cat gensets will provide fast-start capability and more efficient generation at varying load levels. Those factors will help follow load in tandem with intermittent energy supply from renewable resources.

“NorthWestern Energy is an industry leader in reshaping and diversifying its electric generation portfolio, with nearly 58 percent of its energy currently provided by renewable resources,” said Claudio Martino, Caterpillar’s sales manager for medium-speed reciprocating technology in the Americas. “With a fast start time, short ramp-up and ramp-down times, and low operating costs, Cat gas generator sets will help NorthWestern Energy provide reliable and efficient power to its grid.”

Caterpillar is also supplying selective catalytic reduction (SCR) emissions systems, switchgear, exhaust stacks, and control solutions for the new facility, which will be built on the current site.  Construction activities are scheduled to begin in July, with commercial operation expected at the end of 2021.  

Cat dealers will play a prominent role in the design and construction of the power plant. Ziegler Cat will support Fagen, Inc. of Granite Falls, Minn., which was selected as the engineering, procurement, construction (EPC) contractor.  Fagen, Inc. will collaborate on engineering services with Commonwealth Associates, Inc. of Jackson, Mich., with assistance from Michigan Cat.

The Huron Generation Station is the fourth application of Cat G20CM34 generator sets in the U.S. More than 150 GCM34 engines are installed in the U.S. and Canada, representing more than 1,000 MW of installed capacity in power and gas compression projects.

The Cat G20CM34 generator set features a turbocharged and aftercooled natural gas-fired engine that offers ultrafast start times and load acceptance while allowing for multiple fast starts per day.  It delivers high efficiency with low emissions, even under partial loads, according to the company.

NorthWestern Energy provides power to nearly 750,000 customers in Nebraska, Montana and South Dakota.