Transmission project links Alberta to Montana

North America: With its long-planned Montana-Alberta tie line successfully financed and under construction, Toronto-based Tonbridge Power is turning its attention to another transmission project that will connect Montana wind to the US Pacific Northwest.

"We have been working to get to this point for a long time," says Robert van Beers, Tonbridge's chief operating officer. "With the wind resources available in Montana, it is essential that real and commercial solutions for transmission be brought to fruition."

The company is already building a 214-mile transmission link between Lethbridge, Alberta, and Great Falls, Montana, known as the MATL line, which will provide grid access to 600 MW worth of wind farms in the northern part of the US state. It has now signed an agreement with Irish wind developer Gaelectric to study the feasibility of a new 100-mile line that would effectively extend MATL south to interconnect with grid system owned by the the Bonneville Power Administration (BPA) via the 500 kV Colstrip line. The Colstrip transmission line is the major electricity highway that runs east to west out of Montana into the Pacific Northwest states.

Tonbridge and Gaelectric will spend a combined US$500,000 on an 8- to 12-month assessment of the viability of the project, called the Green Line. Gaelectric, which says it has land options in Montana totalling 10 GW of potential, would be allocated at least 500 MW of transfer capacity and would receive its development contributions back through contracted transmission tariff reductions in the future.

Although a decision to proceed will depend on the results of the feasibility study, Tonbridge has already filed interconnection requests with BPA for 1 GW each at two different points on the Colstrip line. "The configuration of this has not been finalised at all yet," says Van Beers. "We've asked for two interconnection points as a way of giving us (options) because we simply don't know what the shippers are going to want, we don't know what the capital costs are going to be, we don't know what the regulatory implications of different routes are going to be."

Capacity auction

Any capacity not allocated to Gaelectric as a so-called anchor shipper will be auctioned to other companies in an open-season bidding process. Van Beers expects most of the interest will come from wind developers who have been stymied by a lack of transmission to move power out of the state. "There is a huge amount of wind ready for development in Montana," he says. "It is going to be, if not exclusively, then primarily wind."

Another Canadian company is also looking to tap into Montana's wind potential, which was ranked second behind Texas and tied with Kansas in a recent Harvard study. Calgary-based TransCanada Corporation wrapped up open seasons on December 16 for space on two proposed 500 kV high-voltage direct-current lines, each with 3 GW of capacity, that will access markets in the US Southwest. One, dubbed the Chinook project, originates in south-western Montana and runs 1000 miles to the Eldorado Valley near Las Vegas, Nevada. The second line, called the Zephyr project, starts in south-east Wyoming and also terminates near Las Vegas. (“uåX˜äŠÊ˜·³Ç, November 2009). Although the results were not released by “uåX˜äŠÊ˜·³Ç's deadline, TransCanada expected wind bidders to dominate.

TransCanada had hoped to sign up anchor shippers for its lines as well, but spokesman Terry Cuhna says the companies it was negotiating with were not in a position to execute agreements before the bidding started in October. "As a result, the Zephyr and Chinook projects offered the full 3000 MW of capacity in the open season," says Cuhna.