Alaskan Susitna Hydro Project with MWH Moving Forward
This project is moving forward for 600 MW of hydropower. It is identified in the Renewable Energy Projects report as follows. MWH is in the second year of a 5 year contract for consulting and engineering.
] Susitna-Watana Hydroelectric Project
Sustina-Watana Hydroelectric Plant
Additional information as to the contractor and history is shown below
MWH Awarded Contract for Hydropower Engineering Services for Hydroelectric Project Studies in Alaska
– MWH has been awarded a two- to five-year contract for hydropower engineering services by the Alaska Energy Authority (AEA) to support the evaluation and development of hydropower projects along the Alaska Railbelt electrical grid. The potential hydropower project(s) under consideration would be a key component to help achieve the state’s goal of producing 50 percent of electrical power from renewable sources by 2025.
Among the projects being examined is an updated project concept for the Susitna River in a remote area in Alaska’s interior between Anchorage and Fairbanks. Last year, AEA focused on two large hydropower projects for the Railbelt, including the Watana site on the Susitna River and Chakachamna, across Cook Inlet from Anchorage. In November 2010, AEA announced its decision that the Watana site should be the primary hydroelectric project for the Railbelt, and Chakachamna should be considered as an alternative. The Susitna project could have an installed capacity of up to 600 megawatts, sufficient to provide nearly half of the current electricity demands of Railbelt communities, including Fairbanks, Palmer-Wasilla, Anchorage and Kenai.
“MWH is proud and excited to work with the Alaska Energy Authority to bring this important development to fruition for the people of Alaska,” says Alan Krause, president and chief operating officer of MWH. “Our company’s roots and work run deep both in Alaska and with these projects; we look forward to bringing our expertise in permitting, licensing, design and construction of world-class hydropower projects to Alaska’s interior.”
Initial project efforts are funded by a $10 million appropriation from the Alaska Legislature. It is anticipated as much as $5 million of this funding will be allocated in FY2011 for engineering activities. Engineering activities include MWH assisting AEA in the evaluation of project selections, feasibility and cost estimates, data collection, conceptual design, permitting, and other required tasks to facilitate AEA submitting an application to the Federal Energy Regulatory Commission (FERC) for an operating license. The balance of funds may be used to support other contracts dedicated to environmental studies for the projects.
A larger Susitna river project was studied by the State of Alaska in the mid-1980s with the assistance of a joint venture that included Harza Engineering, which merged with Montgomery Watson in 2001 to form MWH. Chakachamna was also studied in the same period.
About MWH
MWH, globally driving the wet infrastructure sector, is leading the world in
results-oriented management services, technical engineering, construction
services and solutions to create a better world. The wet infrastructure sector
encompasses a full range of water related projects and programs from water
supply, treatment and storage, dams, water management for the natural resources
industry and coastal restoration to renewable power and environmental services.
MWH is a private, employee-owned engineering consultancy with offices in 34
countries on six continents - including an Anchorage office for the past 30
years. For more information visit the Web site at
www.mwhglobal.com
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source: Creative Commons Attribution Non-Commercial
The proposed Susitna hydro project is a 600 MW facility to be constructed about halfway between Fairbanks and Anchorage on the Susitna River. The total cost of the project is currently estimated at $4.5 billion, not including an additional $900 million for transmission and integration into the Railbelt. The state legislature approved $66 million in 2011 to begin permitting and feasibility studies, with a target date of producing power by 2023.
The facility would displace a large amount of electricity currently generated from fossil fuels, reduce the need for other generation projects, and provide base load to supplement renewable sources like wind and tidal energy that have variable power output. Critics of the project cite debatable economics, impacts on fisheries, earthquake risk, viable alternatives, and destruction of pristine wilderness as reasons to oppose the dam. Most contentious is the large difference between electricity price estimates produced by the developers and by outside consultants (see below).
The hydroelectric potential of the Susitna River was first examined by the US Bureau of Reclamation in 1948. Additional studies took place throughout the next 40 years, culminating in a series of major feasibility studies in the early 1980's. In 1983, the Alaska Power Administration (APA) applied for a hydroelectric permit from the Federal Energy Regulatory Commission (FERC), but the overall price of energy was in decline in the early 1980's and eventually the application was withdrawn, ending all of the ongoing studies. The project gained new life in 2008, when the Alaska Energy Authority (AEA) commissioned a comprehensive review and update of the previous work.
The 1983 FERC application called for two dams, one at Watana and one at High Devil Canyon, that would have provided a combined 1800 MW of electricity. The application was later amended to a "staged" plan to spread out the costs over a longer time period, and estimated to cost $5.9 billion ($11.8 billion in 2010 dollars).
The AEA-commissioned reassessment of the Susitna project examined potential for placing a dam at Watana ($6.6 billion in 2008 dollars) or at High Devil Canyon ($5.4 billion in 2008 dollars). Either alternative was projected to produce around 1200 MW of electricity. Improvements in technology, most notably the option of a roller compacted concrete (RCC) dam instead of a traditional embankment dam, reduced costs per MW relative to the 1980’s estimate.
During the summer of 2011, the Alaska state legislature appropriated $66 million in funds to move the Susitna project forward following two important events in 2010: the passage of a bill requiring that 50% of Alaska's electricity come from renewables by 2025, and the stated strong preference of the AEA for the Susitna project over the Chakachamna hydro project.
source: Creative Commons Attribution Non-Commercial
The current project plan calls for a single dam at Watana capable of generating 600 MW (2600 GWhrs annually) of power at an estimated cost of $4.5 billion. This would provide for about 50% of the existing needs of the Railbelt. This would therefore go a long way towards achieving the state's official goal of 50% renewable power by 2025.
The site is about 50 miles northeast of Talkeetna, which puts it about halfway between Anchorage and Fairbanks. It could be accessed by a new road from the Denali Highway and/or a new rail line from Gold Creek. The dam would be around 700 feet tall and create a reservoir of 39 miles long, up to 2 miles in width at the widest point. One issue that has yet to be resolved is the question of land ownership. Much of the land to be flooded as well as the dam site itself are owned by Native corporations and no access agreements have yet been established.
Costs to construct transmission lines and substations have been estimated 14 MB at an additional $889 million to fully integrate the project into the Railbelt grid.
The price of electricity to be generated from the project is a major debate between proponents and opponents of the dam. The AEA estimates the wholesale price of electricity from the project to be 6.3 cents per kWh. This assumes 50% state financing, a lifetime of 50 years, and doesn't specify the year that electricity would be this price. A 2012 report from the Institute of Social and Economic Research (ISER) concluded that the retail price of electricity would be up to 40 cents per kWh. This assumes no state financing and is only for the first year, with costs eventually dropping (also over a 50 year lifespan). An apples-apples comparison (50 year life, 50% state financing) shows the price of wholesale electricity as being either 6.3 cents/kWh (AEA, unknown year) or 8-18 cents/kWh (ISER, depending on year). The ISER analysis also assumes that the remaining 50% would be entirely financed by loans to utilities, but it is possible federal grants or further state assistance could reduce this amount and the cost of power.
Another complicating factor in the economic analysis is the lifespan of the project. The average projected lifespan of dams in the U.S. is 50 years, but many dams last longer than this. For example the Hoover Dam was completed in 1936 and as of 2011 was expected to produce power until at least 2067. The longer a dam is kept in operation, the lower the total cost of power will be, but the risk of dam failure also increases with age.
The most significant environmental concerns with the Susitna hydro project relate to seismic risk and the impact on fisheries. Other concerns, more general to all hydropower projects, are destruction of wildlife habitat, aesthetic losses, and the production of methane as a greenhouse gas. Opposition to the project has focused mostly on the impacts on fisheries and the cost of the project, with natural gas most often proposed as an alternative.
The proposed dam would have a complex impact on fisheries. For example, rearing Chinook salmon have been reported in two tributaries (Kosina Creek and Oshetna River) upstream of the dam site. These populations would be destroyed by the upstream inundation of the dam. Additionally, several miles of Arctic grayling spawning habitat are expected to be negatively impacted by the reservoir. The presence of the dam would also change the downstream temperatures, flow rates, and sediment levels in the river, and the combination would likely help some fish species and hurt others. The reservoir itself would provide new fish habitat. Downstream effects on the salmon population are difficult to predict in detail. For example, the lower summer flow rates may reduce the amount of salmon spawning habitat, but the increased winter flow and temperature may increase overwinter survival rates.
The Susitna hydro project is in a seismically active area, with major faults north and south of it. Construction of a large dam in this region would need to take into account the probability of a large earthquake in the area and designing the dam to be safe would require extensive, careful work. Building dams to withstand earthquakes is a difficult, but well-studied, engineering problem. In its 2010 report "Railbelt Large Hydro Evaluation," the AEA states:
"The design earthquake for the Susitna Project would likely be a based on consideration of a Denali fault event somewhere in the range of magnitude 8.0, a local crustal earthquake and a subduction zone earthquake with a magnitude of roughly 8.5."
The AEA also notes that good seismic data for the area exists as a result of the magnitude 7.9 Denali Fault earthquake in 2002, and that subsurface conditions at the site are well understood due to extensive drilling in the 1980's.
During the summer of 2011, the Alaska state legislature appropriated $66 million for feasibility studies and to begin preparing for a FERC application. AK Governor Parnell suggested that the project could be complete in 2023. This timeline allows around six years for permitting and five years for construction.
The governor also announced in July 2011 that the (AEA) is actively preparing to file the FERC application, detailed mapping of the project site is underway, and the Department of Fish and Game is assessing fish populations in the area. The official pre-application to FERC was submitted in January 2012. Public meetings were held throughout March 2012. The AEA proposed an official study plan in July 2012.