Idea for a Kauai Large Scale Wind Energy Location

Was looking at a neat map of Kauai here, and got a brainstorm:

First Wind was going to be re-engaging the Kauai community about a possible wind project in early December 2008. First Wind has an existing successful project on Maui expected to be enlarged, and it also is developing a plan for a large wind project on Molokai.

In looking at the wind profile of Kauai, there are two places that fall into the highest wind profile category which we had not paid close attention to in the past. One of those is about one nautical offshore south of Poipu. Setting the esthetics there aside for a moment, the ocean floor there a mile out is about 35 fathoms deep or about 64 meters which is about 24 meters deeper than windmill foundations usually are built offshore. The water there also drops off steeply beyond the one nautical mile out to 100 to 200 fathoms deep. Not to mention the esthetics of this at the Poipu location.

The other, second location offshore of Kauai is much more interesting. This highest wind profile location is northwest offshore of Kauai. It is a large area and at first glance looks too far and too deep offshore. But looking at a nautical chart map compared to the DBEDT wind profile map, we can see the most ideal location there is between 1 and 2 nautical miles northwest offshore of Milolii Point.

One nautical mile out there, the depth is 12 to 13 fathoms or 22 to 24 meters deep. At 1 1/2 nautical miles out there, the depth is 15 to 17 fathoms or 27 to 31 meters deep. At 2 nautical miles out there, the depth is 30 to 31 fathoms or 55 to 57 meters deep. Offshore windmill projects in Denmark, Holland, the Baltic and North Sea are built in ocean depths of 5 to 40 meters.

The optimal wind power density profile of 600 to 800 W/m2 starts at about 1 nautical mile offshore of Milolii Point with an apparent zone of over 800 W/m2 a little less than 2 nautical miles offshore of Milolii. Windmill placement northwest of Milolii Point could be as much as 1 3/4 nautical miles offshore in a depth there of as much as 35 to 40 meters.

Power lines to the area do run at least as far as the center of PMRF. The U.S. Department of Energy is developing an Hawaiian Islands interisland power cable project, initially to move wind generated power between Maui County to Oahu. Kauai was told last September it won't be a part of it, but it may be possible to get funding under that program for a cable from the above Milolii Offshore Wind Farm to the north end of PMRF at Nohili Point (about 7 nautical miles) or directly to shore (less than 2 miles) with some additional landlines laid.

PMRF/DoD may be willing to fund some additional landlines and possibly battery storage if the energy is sold to both PMRF and KIUC. For this to be realistic, the Milolii Offshore Wind Farm would need to be large enough to be useful to both, at least 20 wind generators and possibly more.

Experience in places like Samso indicates that the cost of offshore wind generators can be as high as 50% more than on land, but leases and fees for wind generators on land on Kauai would exist in perpetuity whereas it is possible that the offshore Milolii location could have NO leases or fees with state and federal permission, thus enabling the higher initial offshore installation costs.

This idea also avoids much of the windmill and birds problem on Kauai as the vast majority of the bird population on Kauai does not venture the mile or more offshore where these wind generators would be. The location and depth proposed is also beyond most shoreline reef.

Aloha, Brad