Powering Large Mines in Alaska

Power in AK

Electrical intertie near Healy, AK

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Background

Mines are both large consumers of power, and a driving force for new capacity, generated from fossil fuels, as well as potentially from renewable resources. 

Metal mines often need an extraordinary amount of electricity; especially if their mining method relies on grinding or "milling" the rock to separate out tailings (heap-leach operations recover less metal, but require less power).  Adding a new mine to an electrical grid can be a huge burden on infrastructure, but the promise of long-term steady demand can also drive large power projects forward, and mines will often work with utilities to build more capacity to meet their demand. For example, mines or mining guarantees were responsible for most of the hydropower plants that currently provide Juneau with relatively low-cost electricity.  Mining companies gravitate towards the source of power with the cheapest sticker price, but this doesn't take into account the true cost of generating that power.

Existing Mines in Alaska

The power needs of Alaska's current and proposed mines are summarized in the adjacent figure.   Both Pogo Mine and Fort Knox Mine draw power from the nearby electrical grid, provided by the Golden Valley Electrical Association (GVEA). Diesel fuels the majority of GVEA’s power plants, but the company also uses naphtha and coal.   Greens Creek Mine generated power primarily from diesel until around 2006, when they began to access new hydropower capacity on the mainland.  Currently Greens Creek draws 95% of their electricity, most of which is hydropower, from the Alaska Electric Light and Power Company, although low water levels forced them them back to on-site diesel generation in summer 2011.  Kensington Mine generates power onsite from six diesel generators.  The recently opened Nixon Fork Mine uses airlifted diesel for power generation.  Likewise, Red Dog Mine is the largest operating mine in Alaska and derives all of its power from diesel generators on site.  In recent years, Red Dog has annually consumed almost 17 million gallons of fuel onsite, and an additional 150,000 gallons of jet fuel for transportation needs.

Proposed Mines in Alaska

Major mine proposals include Pebble (Copper & Gold), Donlin Creek (Gold), Livengood (Gold), Chuitna (Coal), and the Niblack (Gold) prospect.

The proposed massive Pebble Mine anticipates a need for around 300 MW of power, which is more than the total capacity of GVEA (277 MW, supplying Fairbanks, Delta Junction, Healy and Nenana).  The mine has considered several options to bring natural gas to generators onsite, namely installing new capacity in Cook Inlet, building a spur from the proposed natural gas pipeline, or importing liquefied natural gas (LNG).  The most recent statements from Pebble suggest that imported liquefied natural gas is currently the most likely possibility.

The proposed Donlin Creek Mine is in a much more remote region of the state, and the owners have considered and discarded a range of power options from coal to biomass to wind. Currently the company is considering development of a 320-mile natural gas pipeline running from Cook Inlet to the mine site.  Donlin Creek anticipates a need for around 130 MW of power.

Situated close to Fairbanks, the proposed Livengood project would most likely draw power from GVEA, although the mining company has said that it would consider onsite generation.  The Livengood project would require 10-15MW of power if it were a "heap-leach" only operation, and 70-80MW if they install a mill.

The proposed Chuitna Coal Mine, located near Cook Inlet near Chugach Electric transmission lines, would not require as much power as a large hardrock metal mine since no mill is needed.  The mine would use up to 20 MW of power.

The Niblack prospect is in southeast Alaska, an area rich in hydropower potential. This prospect is still many years from possible development but the owners have suggested that around 11.5 MW would be required.  In addition, the owners of the prospect have been in discussion with the manager of the Reynolds Creek hydropower, a project under construction on Prince of Wales Island as of spring 2011.

Date Created: Sun, 24 Apr 2011 05:54:19 -0800

Last Modified: Sun, 4 Dec 2011 20:07:39 -0900