AS PART OF A $1.2 billion agreement to comply with the Clean Air Act, Dominion Virginia Power Company agreed to install state-of-the-art, emissions control equipment to sharply reduce air pollution from eight coal-fired plants in Virginia and West Virginia. At the Chesterfield Power Station the upgrade included the installation of selective catalytic reduction (SCR) equipment on Units 4 and 5.
Dominion’s Chesterfield Power Station is the largest fossil-fueled power station in Virginia. Located about 15 miles south of Richmond on the James River in Chesterfield County, the station can generate more than 1,700 megawatts. Chesterfield supplies about 12 percent of the electricity used by the four million people the utility servers.
Alstom Power Company was awarded the contract for the installation of the two SCR systems on Units 4 and 5. However, to reduce costs and downtime, Alstom Power decided to rent the cranes, forklifts and scaffolding from Rental Service Corp (RSC) for the SCR installation.
Installation of the SCR on Unit 5 began in October of 2000 and was completed in June 2002. Similarly, the SCR installation on Unit 4 began in January of 2002 and was completed in May of 2003. The price for project was approximately $40 million.
According to Jerry Clark, district manager, Alstom Power, it was apparent from the start that rental equipment was going to be a factor from a cost and availability standpoint. “We knew we were going to need more equipment for such a large project,” Clark said.
According to Don Martin, an RSC sales representative, Alstom began searching for rental equipment that could meet the demands of this project. Because of the time frame, and varying weather conditions, Alstom was looking to rent large amounts of different types of construction equipment including cranes, forklifts and scaffolding. Responding to the demands of Alstom’s on-site project management, RSC was able to respond quickly in supplying the equipment to the site.
The scope of the Chesterfield plant project consisted of retrofitting gas bypass equipment, installing SCRs and connecting them into existing ducting. According to Clark, limited access and aggressive schedules were the most challenging aspects of the project. Each job required detailed studies to determine the sequence of installation and then selecting the best equipment for the application.
Dominion Virginia Power’s Chesterfield Unit 5 SCR retrofit. Photo courtesy Rental Service Corp.
Depending upon the complexity, plant lay out and work area accessibility, retrofitting SCRs can take from 15 to 20 months to complete. However, at Chesterfield, renting the equipment eliminated the need to purchase and store the equipment between projects. This reduced installation time and reduced costs because Alstom was only charged rental fees when the equipment was actually being used.
The rental approach also eliminated the need to coordinate equipment delivery to the site as the work progressed. RSC was responsible for making sure that the equipment was on-site when required. The flexibility to return equipment to the local RSC supplier for time periods when equipment was not needed was another benefit of renting.
To reduce or eliminate freight costs, Alstom typically rents equipment from suppliers near the project. “We feel there are several benefits of renting, but for us the main reason is the reduced cost for maintenance,” says Clark. Renting the equipment also reduced installation time at the Chesterfield plant because when a piece was unable to be used due to servicing or repair, it was immediately replaced by RSC.