Missouri-based Empire District Electric (NYSE: EDE) plans an Oct. 23 groundbreaking for the Riverton Unit 12 combined cycle expansion, which would add extra capacity at an existing gas-fired power plant in Kansas.
Originally completed in 2007, Unit 12 is currently a simple cycle natural gas-fired combustion turbine with a capacity of about 143 MW. The conversion to combined cycle operation will include the installation of a heat recovery steam generator, steam turbine generator, auxiliary boiler and cooling tower. This highly efficient configuration will allow for the recapture of excess heat from the existing unit to produce about 100 MW of additional generation, the company said in an Oct. 21 statement.
Burns & McDonnell will serve as engineering, procurement and construction contractor for the expansion. At peak construction, the project will employ 140-150 workers.
Upon completion of the combined cycle project in 2016, the three oldest generators at Riverton, which are Units 7, 8 and 9, will be retired. Units 7 and 8 historically operated utilizing coal fuel, but were transitioned to natural gas operation in 2012. After more than 100 years, this transition brought to a close the coal generation era at Riverton.
Said Blake Mertens, vice president of energy supply: “The new plant configuration at Riverton ensures we continue to provide safe, reliable energy to our customers with least-cost resources while significantly lowering emissions when compared to coal-fired generation. While this ends the coal era at Riverton, this investment will extend the life of the plant and continue to afford jobs in the community of Riverton.”
Uprated Riverton Unit 12 is part of a broader air compliance plan
In order to comply with environmental regulations, Empire District Electric is taking actions to implement its compliance plan and strategy (including adding a new scrubber at Asbury), the utility said in an integrated resource plan filed July 1 at the Missouri Public Service Commission.
This compliance plan calls for:
- the installation of an SO2 scrubber, fabric filter, and powder activated carbon injection system at the Asbury plant (collectively referred to as the Asbury air-quality control system or AQCS) by early 2015 at a cost of $112m to $130m. The Asbury plant consists of two coal-fired units totaling 203 MW. Unit 1 (189 MW) was installed in 1970 and Unit 2 (14 MW) was installed in 1986. The Asbury AQCS and turbine project was currently in progress as of the filing of this IRP. The addition of this air control equipment will require the retirement of Asbury Unit 2, which has been used for peaking purposes, but the surviving Asbury Unit 1 will gain efficiencies and be uprated from 189 MW to 194 MW;
- the transition of the Riverton Units 7 (38 MW) and 8 (54 MW) from operation on coal to full operation on natural gas. Riverton Units 7 and 8 last burned coal in the fall of 2012. Unit 7 is rated at 38 MW burning 100% natural gas and was installed in 1950. Unit 8 is rated at 54 MW burning 100% natural gas and was installed in 1954;
- the now gas-fired Riverton Units 7 and 8, along with Riverton Unit 9, a small gas/oil-fired combustion turbine that requires steam from Unit 7 for start-up, are to be retired upon the conversion of Riverton Unit 12 simple-cycle combustion turbine facility to a combined-cycle unit. The conversion of Riverton 12 was included as a committed resource for the IRP compliance filing.