Juneau Commission on Sustainability
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Hydropower
Background
Southeast Alaska is blessed with abundant water and steep terrain, resulting in a huge hydro power resource. The total theoretical hydro potential of SE Alaska is probably in excess of 10,000MW of capacity, with only about 200MW of this potential already tapped. Much of this potential will not be developed due to environmental concerns, or is located in protected wilderness areas or national parks. However, hundreds of remaining hydro power sites (mostly small-scale) could be developed with minimal environmental impact. Most of the region’s existing and proposed hydroelectric sites are lake-tap developments, on relatively small drainage basins with heavy runoffs. These lakes, typically formed by glaciers which receded after the last ice age, are perched at higher elevations, with tunnels or penstocks leading to powerhouses at lower elevations. Lake-tap projects often do not require a dam, and thus tend to have relatively low environmental impacts.
Regional hydro power resource assessment studies in SE Alaska date back to the 1920s, with the first report being “Water Powers of Southeastern Alaska” (US Forest Service, 1924). In the 1940s, the comprehensive study Water Powers Southeast Alaska (Federal Power Commission and US Forest Service, 1947) evaluated over 200 potential hydro power sites in SE Alaska, and also discussed a regional transmission system to interconnect hydroelectric plants and communities. The last regional study specific to small-scale hydro resources were commissioned by the US Army Corps of Engineers (CH2M Hill, 1979). This 1979 study was a reconnaissance-level analysis of mostly small (less than 10MW) run-of-river sites near twenty small communities in SE Alaska. A more up-to-date region-wide small hydro resource assessment is needed.
SE Alaska’s largest hydroelectric plant is the 78MW lake-tap Snettisham facility near Juneau. In addition, the region has sixteen existing hydroelectric plants in the small (1MW-50MW) category, six mini hydro plants (100kW-1MW), and at least ten micro hydro (less than 100kW) installations.
Source: Water Power Magazine. Brian Yanity 2009; http://www.waterpowermagazine.com/story.asp?storyCode=2053893
Juneau’s Hydropower and Grid System
Juneau’s electrical grid extends from the end of Thane Road at its southern boundary to end of North Douglas road to the Hecla Greens Creek Mine on its western boundary. High power transmission lines extend to Lena Cove where a smaller transmission line further extends to the Eagle Beach area on the northern boundary of the Juneau Grid system.
On December 5, 2012, the City and Borough Assembly passed Resolution 2632: A Resolution Expressing Assembly Support for the Extension of Electrical Power along the Veterans Memorial Highway. This extension would provide electrical transmission and service to the northern public and private lands of the City and Borough of Juneau.
Juneau Hydropower Plants existing, under development and planned supply
Juneau, Alaska was a pioneer in early hydropower development. This development was ushered by the Juneau Goldbelt mining operations which needed low and lower cost energy to extract gold from low grade ore bearing rock. The early hydropower plants of Juneau: Annex Creek and Salmon Creek Dam were developed to serve the mining industry. Today, Juneau receives most of its electrical generation from hydropower that is supplement by diesel. In 2012, the Coeur Alaska Kensington Mine installed its 7th diesel generator in order to keep up with its growing demand for energy. The Coeur Alaska Kensington Mine is 100% on diesel generation and the Hecla Greens Creek Mine switches to 100% diesel generation whenever water reservoir levels are too low for AEL&P to supply them with electricity.
Juneau has five operating hydroelectric facilities and two under development or planned stages to meet current and future demands for Juneau’s economy.
Sources- FERC preliminary permits, FERC licenses and Personal Communications—
Energy capability in Juneau depends on precipitation. In a very dry year, energy capability is 357 gigawatt-hours per year (GWh); in an average year, energy capability is 420 GWh per year; in the wettest years, energy capability is 518 GWh per year. In 2010, total GWh consumed was 396; had there been additional energy produced, it could have been used by non-firm customers. (Personal communication, Scott Willis, May 2011 for CBJ Climate Action Plan).
Juneau Hydropower Electrical Supply and Demand
(From CBJ-Community Development Department-Planning Commission Document)
As the simple set of projections shown in the figure below, Juneau Hydro Supply and Demand, shows, conversions of heating and transportation energy sources from oil and gas to electric have the potential to raise the community’s demand for electricity beyond what is available. In this Figure, the Demand with Conversions (Projected) line shows what would happen if all existing and new heating and vehicles were converted to electric systems, using current technologies.
The cost of generating additional electricity with diesel would raise the cost of electricity so as to eliminate much of the financial justification for conversion;however, the increased cost of additional energy generated by diesel would be diluted with existing lower-rate hydropower, and could still yield economic ratepayer advantages for conversions. The take-away from this graph is that Juneau’s potential hydroelectric supply can easily be outstripped by Juneau’s demand for energy, and that conservation of existing supply and reduction of demand will be necessary to avoid reliance on expensive diesel-generated electricity in the future.
Figure 1: Juneau Hydro Supply and Demand (Source: CBJ Community Development)
Juneau’s hydropower resources are not limitless. In years with low rainfall, hydropower production must be supplemented with standby diesel generation. Permitting and Licensing new hydropower facilities, which is regulated the Federal Energy Regulatory Commission is a time consuming process. Permitting and licensing on a national average can take three to five years with one to two years for construction. Therefore, the lead times required to place additional hydropower facilities on line take long planning horizons.
Juneau has a hydropower project currently under development at the Sweetheart Lake Hydroelectric Project and a planned future hydropower project at Lake Dorothy Phase II.
What would cause Juneau to need more hydropower?
The Regulatory Commission of Alaska tariff provisions require a regulated utility to serve all customers within its service district. Most of the City and Borough of Juneau road system is in the service area of AEL&P. However there is no utility service north of Eagle Beach in the northern section of the CBJ.
Juneau is in hydropower balance with firm rate customers. That means that those AEL&P customers in rate classes that are firm and not “interruptible” have current hydropower generation to meet their demand. Interruptible rate customers such as Hecla Greens Creek Mine, which is the largest single interruptible customer of AEL&P, is historically taken off AEL&P generated power whenever water reservoirs are too low to satisfy firm rate payer current and expected demand. Other interruptible customers include the Princess Cruise Ship dock and the Federal Building heating system. In addition, the Coeur Alaska Kensington Mine in the City and Borough of Juneau is not in the AEL&P service area and is connected to the Juneau electrical grid. The Coeur Alaska Kensington Mine produces 100% of its power with diesel generation and through no fault of their own, is the largest emitter of carbon emissions in the CBJ. Interestingly, the Coeur Alaska Kensington Mine produces and uses more electrical power than the City of Skagway and the City of Haines combined[1]. A Coeur Alaska Kensington Mine interconnection to a hydropower source would materially help meet and perhaps exceed the CBJ Climate Action Plan goals of community reduction in green house gas emissions of a 10% reduction by 2017.
[1] Source- Alaska Power & Telephone, the electrical utility for Skagway and Haines
Table 2. Juneau’s approved GHG Emission targets (Source 2011 CBJ Climate Action Plan)
Economically, limited or a lack of adequate hydropower over time could negatively impact Juneau’s economic growth and could lead to more diesel generation or other more carbon emitting fuel supply usage in the Capital city when electrical demand outstrips hydropower electrical supply.
Juneau’s total electrical sales (firm and interruptible customers) grew 10.83% compared from November 2011 to November 2012. AEL&P sold 329,250,834 kWh in 2011 and sold 364,906,469 kWh in 2012 through November of each year.[1] These sales numbers do not include December sales of either year. Hydropower projects are reliant on precipitation and rain fall. Lower water years means that hydropower projects produce less power than in higher water years.
Industrial and commercial growth is not the only electrical energy demand looming for Juneau. In addition to economic growth that could develop by means of new subdivisions, new commercial ventures, and new mining activity, there is also economic fuel substitution that occurs when people switch from high cost fuel sources to lower cost fuel sources. Based solely on the cost of competitive fuel sources (aside from the impact on GHG), oil to electric conversions growth is the other primary reason that Juneau will need more hydropower in the near and long term future. The recent draft Southeast Integrated Resource Plan (SEIRP) identifies the “Oil to Electric” conversion phenomenon as a threat to hydropower dependent communities.
“In communities where hydroelectric power is available, rapid conversion from heating oil to electricity for space heating has been common in recent years due to the lower cost of hydroelectric electricity for home heating and other uses. While a benefit to users who convert to electricity, this has had the effect of reducing the availability of excess hydroelectric generation and increasing the reliance on diesel generation for communities having limit