Swan Lake North Hydro LLC, an affiliate of EDF Renewable Development, applied Oct. 27 at the Federal Energy Regulatory Commission for a license on the 393.3-MW Swan Lake North Pumped Storage Hydroelectric Project in Oregon.
This is to be a pumped storage hydroelectric project with a total installed capacity of 393.3 MW in turbine mode, consuming around 300 MW by the end of the pumping cycle. It will be located roughly 11 miles northeast of Klamath Falls in Klamath County, Oregon. The Oct. 27 filing was of a Final License Appllication.
Excluding the transmission right-of-way (ROW) and associated temporary construction access roads, the proposed project boundary encompasses approximately 857 acres and stretches from the west side of Grizzly Butte to Swan Lake Rim. The upper reservoir and its associated features are to be located on Swan Lake Rim, a high desert plateau rising approximately 1,500 feet (ft) above the Swan Lake Valley. The lower reservoir, powerhouse, and open air terminal are all to be within the Swan Lake Valley, a 10-mile-long lake basin.
The transmission ROW is approximately 32.8 miles long and runs generally southeast from the project site, west of Dairy and Bonanza, east of Bryant Mountain, to the Bonneville Power Administration‘s (BPA) Malin Substation.
Three variable speed, reversible pump-turbine generator units will be installed in the powerhouse. Each unit will have a rated generating capacity of 131.1 MW for a total plant rating for pumping and generating of 393.3 MW. The gross turbine head range will be between 1,627, and 1,720 ft. The project is designed to be capable of operating 24 hours per day in combination of generating and pumping. It is anticipated that at least one pumping and one generating cycle will occur every 24 hours.
Pumped storage is essentially a way to store energy, by pumping water up a hill during low power demand periods, when electricity is cheap and somewhat unneeded, and releasing the water for hydropower production during peak demand periods. It is seen as a viable way to even out the variable output to the grid of solar and wind projects.
The company originally considered the possibility a 1,144-MW project. This initial project was described in the December 2008 preliminary permit application. During the pre-application study process the applicant downsized the project to 1,000 MW and moved the lower reservoir. The 1,000 MW alternative was described in detail in the 2011 Draft License Application (DLA) for the project.
The project was re-designed in late 2014 with a smaller capacity, based on needs of the local energy grid and an increased ability to address environmental concerns with the smaller project, the application noted. This 393.3-MW version of the project requires smaller reservoirs, the locations of which were revised to further reduce potential environmental impacts. Additionally, the transmission alignment was modified from the route selected during the transmission line corridor alternatives analysis after the DLA was filed to further reduce environmental and visual impacts.
Said the Oct. 27 application: “Early indications of the review revealed that a large project, such as the proposed DLA Project, would not achieve economies of scale in creation of economic benefit, though it would create economies of scale in cost alone. Looking at the net-cost-benefit, a larger DLA Project would be underutilized, provide less benefit to the grid, and be noncompetitive with other energy technology. Further, such a large project would create additional congestion on the existing transmission grid, and would likely require significant transmission infrastructure improvements that would further significantly reduce the benefit of the DLA Project. The scenario analysis looked at projects of smaller size, at the 600 MW and 400 MW level. It was determined that a distinct inflection point in the economic data at approximately 400 MW was visible where the net-cost-benefits became markedly worse above this level of capacity. Smaller capacity sizes down to 300 MW were technically feasible, but no less expensive due to many engineering constraints.”