SWEETWATER COUNTY — The Jim Bridger Plant has been a Sweetwater County fixture for decades and its future appears bright even as PacifiCorp is looking to potentially close two of its units in the next 20 years.
PacifiCorp’s 2017 integrated resource plan seeks a transition “to a cleaner energy future with near-term investments in both existing and new renewable resources, new transmission infrastructure, and energy efficiency programs,” according to its executive summary.
“The primary objective of the IRP is to identify the best mix of resources to serve customers in the future,” it states.
“For the company as a whole, all power plants built by the company since 2000 have been either natural gas or wind,” PacifiCorp Spokesman David Eskelsen told the Rocket-Miner. “Current long-range planning envisions further development of renewable generating resources, principally wind, with no fossil fuel additions within the current planning horizon.”
As part of the resource plan, the company is also looking at a early retirement date of 2028 for Jim Bridger unit one and 2032 for unit two.
“The integrated resource plan notes the ‘assumed end-of-life’ for generating units,” Eskelsen said. “These dates are based on regulatory depreciation, an accounting tool used to anticipate the recovery of construction and financing costs through customer rates. Although, they are not hard retirement dates.
“The decision on unit retirement is based on financial analysis informed by the IRP, but based on the least-cost, least-risk mix of generating resources for customers.”
There are many preparations required before a plant can cease operations. Plant inventories and supplies are adjusted to anticipate unit retirement, plans are developed and actions are taken if any changes are needed to be made to the transmission network in preparation for the plant’s retirement, Eskelsen said.
In 1969, PacifiCorp and Idaho Power jointly proposed a new power generating plant in Wyoming, which became the Jim Bridger plant. It sits about 10 miles north of Point of Rocks.
The four-unit plant was completed in stages, beginning in 1970. Bridger’s first unit went online in 1974, with three others coming along by 1979. The plant converts coal into electric energy. It has four operating units — each with a 2,800-degree furnace that produces 1,000-degree steam, which turns turbines.
The coal is crushed and transported by a 4-mile long conveyor belt from the Bridger Coal Mine to the plant and by train from the Black Butte Coal Mine. At the plant, fuel handlers mix and blend coal from different seams to gain an optimum blend for a clean, efficient fuel, according to the company.
As part of the resource plan, PacifiCorp is also working on a series of projects to expand its wind energy production.
The Energy Vision 2020 project would add three new wind projects in Wyoming that will provide 1,150 megawatts of new wind energy capacity, add a new 140-mile high voltage transmission line and repower 900 megawatts of the company’s existing wind resources in Wyoming and Washington state.
Five years ago, Rocky Mountain Power, a division of PacifiCorp, reported relatively slow growth in customer demand for electricity. This was due to the continuing effects of the 2008 recession plus the impact of energy conservation measures by the company’s demand-side management programs. Eskelsen said programs included cash incentives for customers to install more efficient lighting, air conditioning systems, refrigerators and other electric appliances.
The company was also in the midst of a program to install improved environmental controls on several of the company’s coal fueled generating units, including the Jim Bridger Power Plant. Selective catalytic reduction systems to reduce nitrogen oxide emissions were completed on Jim Bridger unit three in 2015 and unit four in 2016.
“We continue to work with state and federal environmental agencies to ensure that the Bridger plant, as well as all our facilities, strictly comply with all applicable environmental regulations, while continuing to work for innovative solutions yielding positive environmental impacts,” Eskelsen said.
The resource planning process is completed every two years with a review and update done in the off years. The next IRP is scheduled to be finished in April 2019. Public meetings for the planning process are being conducted.
“As with all of our available sources of energy, the company will continue to evaluate Bridger’s role in maintaining a reliable, low-cost, environmentally conscious portfolio of generating resources,” Eskelsen said. “We do this using the public process that develops our integrated resource plan, which is published every two years.”
He said the Jim Bridger Plant will continue to be a valuable resource for its customers in the foreseeable future.
For more on the next steps, go to www.pacificorp.com/es/irp/pip.html.