In today’s environment of higher energy prices and incentives for clean energy, development of more than 75 hydro projects totaling 11,000 MW is being actively pursued in the U.S. This additional capacity comes from adding hydro at non-hydro dams, developing pumped-storage projects, building conventional small hydro, and installing turbines on water conveyances.
Today in the U.S., development of more than 75 new hydro projects totaling 11,000 MW is being pursued. This article provides examples of this development activity, presented in the following categories:
– New hydro at existing non-power dams;
– Pumped storage;
– Conventional small hydro; and
– Addition of turbines on water conveyances.
Adding hydro at existing dams
Of the approximately 80,000 dams in the U.S., less than 5 percent impound water for power generation. There is the possibility of building significant amounts of new hydroelectric capacity at these existing structures. In the past four years, six new hydro projects totaling about 40 MW have been built at existing dams. And, interest is growing.
Currently, one facility is being constructed and 40 more are being pursued to provide about 920 MW of new renewable hydroelectric capacity – without constructing additional dams. (See Table 1 on page 20.) More than half of these projects – 24 – are being pursued by BPUS Generation Development LLC. Of the remaining projects, about half are being developed by public agencies: municipalities, cooperatives, water conservation districts, and energy authorities. The rest are being pursued by privately owned companies.
One organization pursuing development of new hydro facilities at existing dams is American Municipal Power-Ohio Inc. (AMP-Ohio).
AMP-Ohio, which represents 122 municipal utilities in six states, is adding more than 230 MW of new hydro capacity at existing U.S. Army Corps of Engineers locks and dams along the Ohio River. Projects being developed are:
– 82-MW Cannelton powerhouse at the Cannelton Locks and Dam in Kentucky;
– 48-MW Robert C. Byrd powerhouse at the Gallipolis Lock and Dam in Ohio;
– 74-MW Smithland powerhouse at the Smithland Navigation Project in Kentucky; and
– 35-MW Willow Island powerhouse at the Willow Island Lock and Dam in West Virginia.
In 2006, to keep up with the changing power needs of its members, AMP-Ohio commissioned engineering firm R.W. Beck to conduct a load study. The study anticipated that the total load of AMP-Ohio members would reach more than 3,600 MW by 2012, a 12 percent increase from 2007 levels. In supplying the power to meet this growth, AMP-Ohio wanted to provide its members with a balanced portfolio, including renewable resources. Hydro was the most attractive option. Consequently, AMP-Ohio commissioned MWH Americas to identify the most promising sites for hydro projects on the Ohio River. Cannelton, Gallipolis, Smithland, and Willow Island dams were identified as good candidates for development.
In March 2007, AMP-Ohio received Federal Energy Regulatory Commission (FERC) licenses for projects at three of these sites. Construction of the three powerhouses (Cannelton, Smithland, and Willow Island) is to begin in the late spring/early summer of 2008. This work includes building cofferdams and preparing foundations for powerhouses at each site. AMP-Ohio also plans to invite bids for construction of cast-in-place reinforced-concrete powerhouses. MWH Americas is providing engineering design services for all three projects. H.C. Nutting Co., under a subcontract to MWH, is performing geotechnical investigations.
In total, early estimates suggest the projects will cost more than $800 million. AMP-Ohio has commitments from its members that will cover all development and capital construction costs associated with Cannelton, Smithland, and Willow Island. AMP-Ohio has access to a $350 million revolving line of credit for each project with a syndicate of bankers led by JPMorgan Chase & Co. The line of credit can be increased to $450 million for each project at any time before terms expire in December 2010.
To help finance the projects, AMP-Ohio secured clean renewable energy bonds (CREBs). The company secured bonds in two rounds. In November 2006, AMP-Ohio received $2.1 million for Smithland and $4.5 million for Willow Island. In December 2007, the company received an additional $16 million in CREBs. This includes $2.1 million for Smithland, $1 million for Willow Island, and $4.9 million for Cannelton.
For the fourth project, Robert C. Byrd, AMP-Ohio filed an application with FERC in April 2007 for a preliminary permit to study development.
These hydro projects make sense to develop for two primary reasons, says Phil Meier, assistant vice president of hydro development with AMP-Ohio. First, their location at existing dams avoids much civil work construction. Second, the projects will provide a valuable, clean renewable energy resource.
Developing pumped storage
The bulk of planned new hydro capacity – nearly 10,000 MW – is in the form of pumped-storage projects. Development of 15 new pumped-storage projects is actively being pursued by public and private organizations. (See Table 2 on page 22.)
Much of the pumped-storage development activity is occurring in California. This reflects an increased cost structure for the deregulated wholesale California power market, says Douglas A. Spaulding, P.E., president of developer Energy Recycling Co. With high natural gas prices, the value of on-peak power will continue to increase. Over the long term, an increased supply of baseload power from new coal-fired plants will provide a new potential source of pumping energy. Moreover, Spaulding notes that the recent increase in prospects for new nuclear generating facilities promises to increase the need for peaking power.
Another driver spurring development of pumped-storage projects in California is increased production of non-dispatchable and intermittent renewable energy sources, such as wind and solar, says David Hanson, project manager, hydro relicensing with the Sacramento Municipal Utility District (SMUD). Pumped-storage facilities are seen as a tool to manage the power generated by these sources, Hanson says.
His organization is pursuing development of the 400-MW Iowa Hill pumped-storage facility. The Iowa Hill plant would be built on the American River near Camino, California, partially on national forest system lands. SMUD proposed construction of the pumped-storage facility as part of an application to relicense seven existing developments that make up the utility’s 688-MW Upper American River project.
Providing firming services for wind and solar also is a driver in the proposed development of the 880-MW Red Mountain Bar pumped-storage project (formerly called Don Pedro), says Randy Baysinger, P.E., assistant general manager of the Turlock Irrigation District. Turlock, along with the Modesto Irrigation District, is studying the feasibility of developing the project, to be located south of Sonora in Tuolumne County, California. Baysinger says thousands of megawatts of new wind and solar capacity expected to be built in California over the next few years provide a strong market for firming services. In addition to firming services, Red Mountain Bar will provide reserves and ancillary services.
The lower reservoir for the project would be the existing Don Pedro Reservoir, part of the existing 168-MW Don Pedro hydro project. Don Pedro Dam and Reservoir were built in 1971 by a partnership of the two irrigation districts, along with Hetch Hetchy Water and Power and the Corps of Engineers. The reservoir is the sixth largest body of water in California, providing energy production, flood control, agricultural and municipal water supply, and recreation. The new pumped-storage project would include a new upper reservoir, conveyance tunnel, an underground powerhouse, transmission lines, and other appurtenant facilities. Construction of the $1.3 billion project will be financed through bonds. Turlock Irrigation District could start pursuing a FERC license for the Red Mountain Bar project in late 2008.
Conventional small hydro
Development activity is strong for new conventional small hydro projects. Hydro Review is tracking construction of 13 projects totaling more than 40 MW (see Table 3 on page 22). In addition, more than 100 proposed projects with a total capacity of more than 300 MW are being considered.
The state of Alaska is a leader in the development of small hydro, both in number of projects and megawatts. Hydro is attractive in Alaska for two main reasons, says Ed Williams, operations manager for the Four Dam Pool Power Agency. First, some cities in Alaska are remote, accessible only by sea and air, and they require a local source of power. Second, the diesel-powered generators that are used are expensive sources of electricity, due to transportation costs.
Alaska Electric Light & Power Co. is building 14.4-MW Lake Dorothy; Alaska Power and Telephone Co. is building 3-MW Kasidaya Creek; and Gustavus Electric Co. is building 800-kW Falls Creek.
Development of Lake Dorothy, on Dorothy Creek, involves building a new low-level rockfill diversion dam, intake, and outlet works. Construction is being financed through $60 million in tax-exempt revenue bonds. The project is scheduled to be completed in mid-2009. Alaska Electric Light & Power will tie the project into its existing distribution system.
Construction of Kasidaya Creek (formerly known as Otter Creek) began in April 2006 and is expected to be completed by May 2008. This project will intertie with an existing submarine cable that connects the cities of Skagway and Haines. This intertie is intended to supplement other hydro projects in the area during the summer months.
The Falls Creek project, under construction, is expected to be complete by June 2008. Work began in April 2006 on the run-of-river facility. The project consists of a low gated diversion structure, a 9,400-foot-long penstock, a powerhouse, a tailrace conduit, and a 5-mile-long buried transmission cable between the powerhouse and the existing diesel powerhouse in the city of Gustavus.
Table 1: New Hydro at Existing Dams in the U.S. Click here to enlarge image
In addition to these three, two more projects are being developed on neighboring islands in southeast Alaska. Haida Corporation is developing 5-MW Reynolds Creek. Construction is expected to begin in early 2009 and be complete by early 2011.
Ketchikan Public Utilities proposes building 4.6-MW Whitman Lake. Construction is expected to begin in 2010 and be completed by 2012.
Installing turbines on water and wastewater systems
Water conveyance systems often require the relieving of excess pressure. Pressure-reducing valves are a common solution for relieving this pressure. In some cases, a hydroelectric turbine can convert the pressure to electricity.
Generating electricity from excess head along water conveyances is not new. Several cities – including Boulder, Colorado; Wichita, Kansas; and Sitka, Alaska – operate hydro plants as part of their water distribution systems.
Variations of this concept are now being planned by the Utah Board of Water Resources and the Clean Water Coalition of Nevada.
Lake Powell Pipeline Project
The Utah Board of Water Resources is studying the feasibility of developing the Lake Powell Pipeline project. The 69-inch-diameter pipeline would transport 100,000 acre-feet of Colorado River water from an intake near Glen Canyon Dam on Lake Powell approximately 140 miles to three water conservancy districts in southwestern Utah.
While the principal purpose of the project is to supply water to fast-growing southwestern Utah, large drops in elevation along the pipeline route provide potential for hydropower, says project manager D. Larry Anderson.
Anderson says the Utah Board of Water Resources is studying development of five small run-of-pipeline hydroelectric plants varying in size from 1 MW to 3.5 MW with a total capacity of approximately 12.8 MW, a 35-MW peaking plant at Hurricane Cliffs in Utah, and a 10-MW plant at the Sand Hollow Reservoir. Also under investigation is the potential for a pumpback storage project at Hurricane Cliffs of up to 300 MW.
Table 2: Proposed Pumped-Storage Facilities in the U.S. Click here to enlarge image
MWH Americas, Inc. is performing preliminary engineering analysis and environmental studies; Anderson said the Utah Board of Water Resources expected to file with FERC a notice of intent to submit a license application and a preliminary application document for the pipeline and hydroelectric generating facilities by the end of February 2008.
Systems Conveyance and Operation Program (SCOP)
Meanwhile, the Clean Water Coalition of Nevada – a joint powers authority in the Las Vegas area that includes Clark County Water Reclamation District and the cities of Las Vegas, Henderson, and North Las Vegas – is planning and designing the Systems Conveyance and Operation Program (SCOP).
The purpose of the project is to improve water quality in Lake Mead, the main water source for the Las Vegas Valley. Treated wastewater from the member agencies is discharged into the lake. The coalition intends to move the discharge location to an open, well-mixed area of Lake Mead.
Table 3: Small Hydro Projects under Development Click here to enlarge image
To regulate this effluent discharge into the lake and to take advantage of the hydraulic head created by the difference in elevation between the wastewater treatment plants and Lake Mead, the coalition plans to incorporate a pressure-reducing/hydroelectric generating station with a capacity of 16 MW. The station will generate about 85,000 megawatt-hours of electricity each year.
Black & Veatch Corporation completed the conceptual design for SCOP. The firm also completed the environmental impact statement, and developed and supervised the geotechnical investigation program. Black & Veatch engineers are now working on the final design for the hydro station.
This article was compiled by the editorial staff of Hydro Review. Sources of information for the article include HCI Publications’ Internet news service, HydroNews.net, the Federal Energy Regulatory Commission website, and communications with project developers.
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