Xcel wraps up Pawnee air controls, well along on Hayden SCRs

Public Service Co. of Colorado told the Colorado Public Utilities Commission in April 6 semi-annual updates that work is well along and in some cases about completed on new air emissions controls for the coal-fired Pawnee and Hayden power plants.

This report by this Xcel Energy (NYSE: XEL) subsidiary was the sixth semi-annual status report on the Pawnee Emission Controls installation, and described the status of the project as of the end of 2014. The certificate of public convenience and necessity (CPCN) for the emission controls at Pawnee was approved in February 2012.

At Pawnee, testing and commissioning activities have been completed. Performance testing shows the equipment is meeting the Regional Haze limits for NOX and SO2. Reliability testing shows the equipment is operating as intended. Sargent & Lundy was selected to provide consulting and balance of plant engineering services. The detailed engineering is complete, production of final issue drawings are also complete.

Looking at the status of various Pawnee project components:

  • The Flue Gas Desulphurization (FGD) and Selective Catalytic Reduction (SCR) systems at Pawnee are being supplied by Babcock & Wilcox (B&W). The detailed engineering and equipment delivery are complete.
  • The new Induced Draft (ID) fans are being supplied by Howden-Variax. The detailed engineering and equipment delivery are complete.
  • The new waste ash system is being supplied by United Conveyor Corp. The detailed engineering and equipment delivery are complete. Erection of the new ash silo has been completed.
  • Modifications to the Fabric Filter Dust Collectors (FFDC) were awarded to Hartman-Walsh and the modifications have been completed.
  • All balance of plant equipment has been ordered and delivery is complete.
  • The General Construction contract was awarded to The Industrial Co. (TIC) in December 2012 and construction is complete.

In its application for Pawnee, the utility provided a cost estimate for the project of $238.578 million in 2010 dollars. Included in this estimate was the cost of the Sorbent Injection for $2.1 million. That portion of the project is complete and its actual costs were $1.16 million. The remaining emission control projects, SCR and Scrubber, have an escalation factor applied to the CPCN estimate of 2.5%. The current estimate reflects the current project revised estimated cost of $271,770,134. The current estimate reflects the consumption of the project’s contingency and the need for an additional $19,725,592.

The purpose for the additional spend is for the installation of an upgraded and modernized air quality control system that must fit into an existing power plant structure and be compatible with existing process systems. The original estimate was completed prior to the identification of all needed retrofit modifications required to integrate the air quality control system into the existing plant systems.

The Pawnee project closeout was due to be completed at the end of March of this year.

The Pawnee plant is a single-unit, 505-MW facility located at Brush, Colo.

Hayden project on a slower track

The April 6 Hayden report is the sixth semi-annual status report on the Hayden 1 and 2 Emission Controls installation and describes the status of the project as of the end of 2014.

Sargent & Lundy was selected to provide consulting and balance of plant engineering services. Several studies of current operating conditions and impacts of the required new equipment have been completed. It has been determined no additional upgrades to the existing duct or scrubbers is required.

The contract for the SCR equipment was awarded to Hitachi Power Systems America Ltd. Detailed engineering continues and is approximately 99% complete. Initial deliveries began in March 2014.

Upgrades to the existing Induced Draft Fans will be required. Unit 1 will require fan tipping and upgraded motors. Contracts were executed with TLT Babcock for the Unit 1 Fan Tipping and Teco-Westinghouse for the Unit 1 Fan Motor Upgrades. Unit 2 will require new fans and motors. A contract was executed with Howden North America for the Unit 2 Fan and Motor Upgrades.

Requirements for procurement of other equipment, including long lead time electrical equipment and long lead time mechanical equipment have been prepared. Contracts for foundation and general construction were executed with TIC. Construction activities for Unit 1 foundations were completed in December 2013.

The erection of SCR equipment began in May 2014. To date, the following Unit 1 SCR construction activities are complete and tie-in ready: structural steel, ductwork and reactor box, ammonia ejection equipment, ammonia storage area, piping, siding and insulation. Unit 1 SCR electrical was to be completed in February of 2015, and Unit 1 catalysts were to be installed in March 2015. The Unit 1 SCR tie-in outage is planned between March and May of 2015, with final acceptance in November 2015. Construction activities for Unit 2 foundations began in the Fall of 2014, and are planned to complete in April 2015. The erection of the Unit 2 SCR is planned to begin in May 2015 with completion in 2016.

In its application, the utility provided cost estimates for the project of $73.9 million for Unit 1 and $91 million for Unit 2. The company revised its budget for both Units 1 and 2 reflecting needs for the induced draft fans, which resulted in a slight modification of the estimates for both Units 1 and 2, adjusting the original estimates to $74.8 million and $90.5 million respectively.

The Hayden Unit 1 SCR project is due for final closeout in November of this year, while the Unit 2 SCR project is due for closeout in November 2016.

Hayden is a two-unit, 446-MW plant, with 237 MW of that capacity controlled by Xcel, located at Hayden, Colo.

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.