If a deal can be struck between the Lassen Municipal Utility District and Invenergy Wind, a for-profit company that proposes to develop, build and operate a 100-megawatt wind generation project in the Horse Lake Valley near Eagle Lake, both sides can benefit.
Invenergy will use the new or rebuilt transmission lines to carry the power generated by the proposed project’s 67 1.5-megawatt turbines to get that energy onto the grid where it can be sold.
And many of LMUD’s most troublesome transmission lines that frequently fail in the winter will be upgraded at no cost to LMUD or its ratepayers.
The troublesome sections begin with a 54-mile stretch from PG&E’s Table Mountain substation to the Caribou substation. That section is owned by PG&E.
At the Caribou substation, the voltage drops from 230 kilovolts to an antiquated 60-kV line through the 24-mile section from the Caribou substation to the Westwood substation and another 24-mile 60-kV run from Westwood to the Milwood substation in Susanville. Much of LMUD’s system is 60-kV.
According to Invenergy’s preferred alternative, the company would install a 115/60-kV transformer at the Milwood substation. That transformer would be connected to Invenergy’s wind farm in the Horse Lake Valley.
Using a single pole structure, the company would install a new 115-kV line from Milwood substation to the Westwood substation and from Westwood substation to the Caribou substation.
This would provide a double circuit – one at 115-kV and another at 60-kV.
If one line went down, the other would still operate and provide power for LMUD customers.
In addition, Invenergy would build another transmission line to serve the communities around Eagle Lake. Residents in the Eagle Lake area could then have power supplied from both ends of the lake rather than just one side, making a loop.
LMUD would still be able to use the Hat Creek line as an emergency back feed as it does today.
Ray Luhring, LMUD’s general manager, said Invenergy’s proposal “fits with our strategic plans.”
Luhring also said LMUD could possibly save as much as $300,000 on line losses alone with the new transmission lines. Higher voltage means less line loss as the energy moves along the transmission lines.
“The reliability benefit to LMUD is huge,” said Duane Braunegal, an electrical engineer with Invenergy. “You could lose one line, and you wouldn’t know it.”
He called the proposal a “win-win” for the Invenergy and LMUD.
Luhring said the new transmission lines might even benefit Honey Lake Power in Wendel.
Luhring told the directors he didn’t see “any downside” to the proposal.
Braunegal said he would work with the LMUD staff to create a “business arrangement” to facility the proposal. He also said Invenergy would work with PG&E to work on the details with the investor-owned utility.
Luhring told the directors if the LMUD were to undertake such a major upgrade of its transmission lines “it would cost us millions of dollars.”
Director Jay Dow asked why the company couldn’t just add a second 115-kV line instead of keeping the outdated 60-kV line.
Braunegal said the Invenergy initially planned at 200-MW facility in the Horse Lake Valley, but there was a “step-jump” in cost for the transmission lines to carry that much power.
The board took no action on the Invenergy’s proposal.
20 May 2008
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