By Sybil E. Hatch
Photographs by Terry Lowenthal/Bechtel
One-quarter of the world’s coal reserves are found within the United States, and the energy content of U.S. coal resources exceeds that of all the world’s known recoverable oil. Yet in the past decade, the nation witnessed a move away from coal-fired power plants.
The reasons are complex, but utility deregulation, stricter environmental requirements, cheaper natural gas, and advances in the design and construction of gas-fired plants combined to make natural gas more attractive. With the skyrocketing of natural gas prices, however, power producers and regulators have realized the downside of relying so heavily on gas.
Coal is back, in full force. Over the last decade, only about 2.5 percent of new electricity generation capacity in the United States has been coal-fired. In contrast, the U.S. Department of Energy predicts that over the next two decades, that number will jump to nearly 40 percent. Long-term price predictability coupled with improvements in technology have reignited power producers’ interest in coal.
A case in point is the Springerville Generating Station in northeastern Arizona, where Bechtel is building a new 400-megawatt generating unit alongside two existing 380-megawatt units the company designed in the 1980s.
“This new unit will meet a growing need for affordable, reliable power in the West, while contributing to the region’s fuel diversity,” says Jeff Stevens, project director for Tri-State Generation and Transmission Association.
When Unit 3 comes online in 2006, America will have its first new pulverized coal-fired power unit since the Bechtel-built Indiantown Generating Plant in Florida opened in 1995. It also will be one of the most efficient and environmentally sound pulverized coal projects, boasting the latest emission control technology in the new unit (and the planned Unit 4), as well as upgrades to the systems in Units 1 and 2. When all four units are operating, emission levels will be lower than they are today with two units.
Although the demand for new coal-fired plants waned in the United States in the mid-1990s, Bechtel continued to hone its expertise on a number of major overseas plants, including Millmerran, a two-unit supercritical 800-megawatt mine-mouth operation in Australia; the two-unit 724-megawatt Meizhou Wan project, China’s first wholly foreign-owned power plant; and the 440-megawatt Quezon plant in the Philippines.
“Our solid-fuel project teams are made up of the most established, cohesive, and connected group of people in the entire industry,” says Marty Surabian, Bechtel’s project director for the Springerville project. “Their knowledge, relationships, and history of working together let us achieve extraordinary results for our customers.”
In addition to having a highly experienced team, the Springerville project is a leader in implementing Six Sigma, the process-improvement methodology that Bechtel now uses companywide to save time and money for its customers. At Springerville, the whole Bechtel team has been trained in the methodology, and Six Sigma has been incorporated in many aspects of the project.
Structural steel design and erection for the boiler and turbine building are good examples of how Bechtel’s solid fuels group has built on past experience and embraced Six Sigma principles to make dramatic on-site improvements. In a pulverized-coal power plant, the boiler, major mechanical equipment, and all piping, electrical, and mechanical equipment are supported by the steel structure. So the construction schedule depends on the timely erection of structural steel. Bechtel relies on increased shop fabrication and on-site preassembly to allow erection of fewer, larger components more quickly. The patent-pending design was developed for the Meizhou Wan project, advanced at Millmerran, and has been refined further by the Springerville team.
A key innovation of the design is the use of trusses to create a combined boiler and roof support structure. This significantly reduces the number of traditionally framed members and transfers the load of the suspended boiler to the steel columns more efficiently. Another innovation allows large platforms, panels, and stairway tower components to arrive at the site complete with grating and metal decking. After rebar installation and concrete placement, the platforms are lifted into place and connected, providing safe access to upper levels of the structure more quickly.
“By utilizing shop modularization and increasing ground fabrication, we’ve greatly reduced the number of crane picks,” says Greg Wagner, Bechtel’s site manager at Springerville. “This allows us to shave our schedule and reduce costs. More importantly, we improve safety by reducing work done at height and getting earlier access to finished platforms for all subsequent work.”
Positioned for the Future With its combination of talent, experience, technological savvy, and Six Sigma-driven approach, Bechtel is well positioned to take advantage of the resurgence in coal power. “We’re executing Springerville really well and with an exemplary safety record as a result of our team’s focus and close cooperation with the owner group and the labor unions,” says Assistant Project Manager Ian Copeland. “Our work here—and in the recently awarded Elm Road project in Wisconsin—will help reinforce our position as a leader in the market for the 40,000 megawatts of coal-fired power plants under consideration in the United States.”