Wartsila has agreed to supply Rochester Public Utilities (RPU) in Minnesota with a 47-MW natural gas generation plant that should begin operation in the spring of 2018.
The order includes five Wartsila 34SG engines, Wartsila said. No contract price was disclosed. Wartsila said Dec. 30 that the equipment will be delivered in the fall of 2017 and the plant is expected to be fully operational in May 2018.
“Compared to the aged coal and gas turbine based capacity it will replace, the power plant will nearly double the efficiency and reduce hourly carbon emissions by 50%,” said RPU Director of Power Resources Walter Schlink.
The quick-start attributes of the facility will also support increased use of wind and solar energy in Minnesota. The state’s renewable energy standard is one of the toughest in the nation. Utilities are required to go 25% renewable by 2025.
The U.S. subsidiary of Finland-based Wartsila now has about 2,500 MW of generation deployed in the United States.
On the point about coal replacement, the RPU website says about the Silver Lake Plant (SLP): “As of June 1, 2015, SLP is a steam producing facility providing a contracted amount of steam to the Mayo Clinic campus for cogeneration needs. The fuel burned for steam production in the boilers is natural gas. Prior to the transition from an electric generation facility, SLP was a 100-megawatt, coal-fired generating facility. The four boiler/turbine/generator units varied in age and size ranging from Unit #1 at 7.5 MW (1947) to Unit #4 rated at 55 MW (1969). Pulverized bituminous coal was the primary fuel, and was supported by natural gas.”
RPU had requested that Burns & McDonnell Engineering (BMcD) provide preliminary engineering services related to the procurement of new dual-fuel reciprocating engines, resulting in this project. Burns & McDonnell has extensive permitting, engineering, procurement, construction, and start-up and commissioning experience with reciprocating engine power plant projects of all sizes.
Attached to the Aug. 25 agenda for a Rochester Public Utility Board meeting was a project brochure from BMcD that outlined the company’s experience with projects like this one. It said that several recent large reciprocating engine power plant projects have consisted of natural gas-fired, Wärtsilä 20V34SG and 18V50SG reciprocating engines. The first generation of 20V34SG engine generators each produced 8.4 MW with excellent heat rates compared to most simple cycle gas turbine technologies. The more recent gas-fired Wärtsilä 20V34SG engine generators installed in the Lea County power plant each produce 9.3 MW with heat rates less than 8000 Btu/kWh (LHV). The gas-fired Wärtsilä 18V50SG engine generators to be installed in the STEC Red Gate power plant and the Stillwater Energy Center each produce 18 MW with heat rates less than 7600 Btu/kWh (LHV).
Among the projects cited in the company’s brochure:
- City of Coffeyville in Kansas selected Burns & McDonnell to provide full engineering, procurement support, and construction management, permitting, and gas services for the new reciprocating engine power plant. The plant will provide 56 MW utilizing three natural gas-fired Wärtsilä 18.8 MW reciprocating engine generators. Project completion due in December 2016.
- Stillwater Utility Authority in Oklahoma selected Burns & McDonnell to provide full engineering, procurement support, and construction management, permitting, and gas services for the Stillwater Energy Center. Phase I of the Stillwater Energy Center provides 56 MW utilizing three natural gas-fired Wärtsilä 18.8 MW reciprocating engine generators. Project completion due in September 2016. The project is designed to add two future Wärtsilä 18V50SG reciprocating engines in Phase II.
- South Texas Electric Cooperative selected Burns & McDonnell to provide full engineering, procurement, and construction services for the Red Gate Power Plant. The Red Gate Power Plant expansion will provide 220 MW utilizing 12 natural gas-fired Wärtsilä 18.8 MW reciprocating engine generators. Project completion in December 2015.
- Matanuska Electric Authority (MEA) in Alaska selected Burns & McDonnell to provide detailed design and contract administration services for the Eklutna Generation Station (EGS) Project. EGS will provide 171 MW utilizing ten Wärtsilä 18V50DF compression-ignited dual-fuel reciprocating engines. This facility will be capable of running on either a mixture of No. 2 diesel fuel oil (LFO) and natural gas or LFO only. Completion was in January 2015.
- Burns & McDonnell performed engineering, procurement and construction services to add a peaking facility utilizing Wärtsilä reciprocating engines at Goodman Energy Center of Midwest Energy located in Hays, Kansas. Burns & McDonnell’s scope included detailed design, procurement, and construction of the plant. This is a 75-MW, natural gas-fired project using nine Wärtsilä 20V34SG reciprocating engines in Phase I. Three additional Wartsila 20V34SG reciprocating engines are planned for Phase II. There was a completion date in September 2008 for Phase I and in February 2016 for Phase II.