The Colorado Air Pollution Control Division is taking comment until Jan. 16 on a proposed change by Colorado Springs Utilities in the regional haze compliance deadlines for two units at its coal-fired Martin Drake power plant.
The division in November 2013 approved the original compliance schedule. “The proposed change pertains to nitrogen oxides (NOx) compliance for Martin Drake,” said a Dec. 5 letter to the division from the utility. “No changes are being proposed for particulate matter (PM) or sulfur dioxide (SO2) compliance.
“As engineering and fabrication progressed on the Ultra-Low NOx Burners/ Over Fired-Air (ULNB/OFA) controls for Martin Drake it was determined that based on outage schedules, lead times, design considerations, and testing that Colorado Springs Utilities could reasonably install the Unit 6 NOx controls in 2014 and achieve earlier and greater total NOx reductions relative to the August 21 compliance schedule. The construction and design of all BART controls, coupled with the fire restoration effects and outage scheduling, necessitates that Unit 5 ULNB/OFA would need to be moved to the end of 2017 to maintain progress for all controls across all of the units. The resulting impact to the project and outage schedule is that Drake 6 NOx compliance can be achieved in 2014, and Drake 5 NOx compliance can be achieved in 2017. There is no proposed change to the schedule for Drake 7 or Nixon 1.”
There was a May 2014 fire at the Drake plant that knocked units offline. Units 6 and 7 are fully operating at this point, while Unit 5 is not due for revived operation until the end of March. Nixon is another coal-fired plant of Colorado Springs Utilities.
Compared to the schedule approved in November 2013, the proposed revised schedule shifts Drake Unit 6 NOx compliance earlier by one year and delays Drake Unit 5 NOx compliance by one year.
There are three Drake units – Unit 5, Unit 6, and Unit 7 – which have lately been operational, with other units having been retired long ago. Fuel supply to the facility is primarily Powder River Basin coal (PRB) from Wyoming. U.S. Energy Information Administration data shows coal suppliers earlier this year included the North Antelope Rochelle mine of Peabody Energy (NYSE: BTU), the Black Thunder mine of Arch Coal (NYSE: ACI) and the Antelope mine of Cloud Peak Energy (NYSE: CLD), all located in the Wyoming end of the PRB.
- The Drake Unit 5 boiler is a Riley Stoker Stirling type boiler. The unit has been in service since 1960. The unit is nominally rated at 44 MW and utilizes a Westinghouse steam turbine generator.
- The Unit 6 boiler is a Babcock & Wilcox Stirling Power design. It is rated at 66 net MW, also utilizes a Westinghouse steam turbine generator, and has been in service since 1968.
- Unit 7 has a nominal rating of 127 MW. This unit also uses a Babcock & Wilcox boiler and was placed into service in 1974.