Monday, April 7, 2008

Limits in sight on wind energy?

Hawai'i is within sight of maxing on out one of its most effective alternative energy sources—wind. At least, that's the case with today's electrical grid system.
On one island—Maui--the electric utility has already rejected one wind generation plant, saying current planned windfarms are all its grid can handle.
On O'ahu, Hawaiian Electric is looking at two wind suppliers who propose to provide as much as 300 megawatts of wind power—but it is likely to only be able to handle one.
Maui already gets a lot of wind power, 30 megawatts, from the Kaheawa windfarm. To add too much more of such a variable power source would overtax the utility's ability to provide firm power to customers, the utility says.
The Big Island grid already has more than 30 megawatts from three wind fields, and Kaua'i officials are concerned about the impact of a single 12-megawatt proposed windfarm.
HECO spokesman Peter Rosegg outlined the issue with respect to Maui.
“We looked at two excellent projects, one from Shell Wind at Ulupalakua Ranch in eastern, up-country Maui and one from UPC, to roughly double their existing wind farm in Western Maui above Ma'alaea. Deciding which would go first was difficult and came down to location.
“On a small grid like Maui's, there's a limit to how much wind power it can take at one time. Having two wind farms in two locations with two different wind regimes for now will make it easier to accept more wind on Maui's system now,” he wrote via email.
A similar issue exists with the two proposals to power O'ahu. One is UPC Hawai'i Wind Partners' proposal to install a 300 megawatt windfarm on Moloka'i and run the electrical power via undersea cable to O'ahu. Another is Castle & Cooke's proposal to put a similarly sized windfarm on its land on Lāna'i, and to cable it to O'ahu.
Either one would approach a quarter of O'ahu's power. The issue for the utility is, what do you do when suddenly the wind stops blowing? With a massive power drop like that, under current grid scenarios, it could get real dark real fast on O'ahu.
On Kaua'i, where UPC has proposed a 12-megawatt windfarm, the utility asked the wind operator to include enough storage to give Kaua'i Island Utility Co-op one half-hour's notice before it will cut off power to the grid.
In essence, if the wind stops blowing, UPC calls the utility to warn it to fire up some generators. Meanwhile, batteries keep providing KIUC with firm power until it gets the generators going.
It seems to be a feasible partial solution at a small scale, but more work is needed to be able to scale it up to big systems.
Rosegg said that both storage technology and grid management technology need to move forward if the grids are to accept significantly larger proportions of wind power—or any intermittent source of power.
In the Maui scenario, he said: “We hope technology advances for storing and adapting wind power make it possible to add a third wind farm on Maui in the future.”
UPC, meanwhile, has gone to the state Public Utilities Commission to argue that Maui Electric should, in fact, accept the additional wind power.
Meanwhile, on Moloka'i, UPC is holding meetings this week and next with the community, to tell residents about its plans, and to see whether they support them.
“UPC will only build a wind farm if the community supports the project,” the firm said. The project may further be impacted by Molokai Ranch's recent announcement it was closing virtually all its Moloka'i businesses. The wind farm is proposed to be located on ranch now owned by the ranch.
The public meetings are scheduled from 6 to 8:30 p.m. As follows.
Tuesday, April 8, at Kaunakakai Elementary School (Kaunakakai)
Wednesday, April 9 at Maunaloa Elementary School (Maunaloa)
Tuesday, April 15 at the Kilohana Community Center (Mana`e – East End)
Wednesday, April 16 at the Lanikeha Facility (Ho`olehua)
© 2008 Jan W. TenBruggencate