Molokai wind farm: Basic questions and answers (Part 5)

| March 16, 2011 | 0 Comments

By Steve Morgan

Do windmills make noise?

A study in Albany County, Wyoming determined that the Siemens 2.3 megawatt wind turbine, at a speed of 22 mph, generated a noise level of 47 decibels (db) at 800 feet away, 40 db at one-and-a-half miles away and 21 db at seven miles away. Comparable studies showed little noise variation in winds ranging from 15 mph to 30 mph.

Examples of comparable noise levels are: Library ambience 30 db, refrigerator hum 40 db, air conditioner (20 feet away) 60 db.

According to the EPA, noise levels above 45 db can disturb sleep. The wind itself also makes noise, which may compete with or even eliminate turbine noise.

A more controversial noise problem associated with windmills is “amplitude modulation” created by infrasound waves under 20Hz. Various studies seem to deny any true medical condition associated with this problem however, an AWEA report states that, “the fluctuating noise created by the up down motion of the blade can be a concern.” Low level frequencies can affect the vestibular system and effect balance and even create dizziness. Some living in close proximity of windmills have reported these type of effects.

*Study conducted by EMI for Shell Energy

What will happen to the windmills if they are no longer in operation?

According to both First Wind and Pattern Energy, upon ceasing operation, all windmills would be removed as well as the concrete support bases. Elaborating on this more fully, David Parquet of Pattern Energy stated that his company would bond the dismantling process. Bonding would insure that money would be a set aside at the development stage of the project in order to cover all related costs of dismantling. Bonding also insures that these allocated moneys could only be used for the sole purpose of dismantling.

Will the Kaunakakai wharf have to be modified to accommodate loading or transportation of turbines?

According to First Wind, the wharf would need modifications to accommodate the large blade and tower pieces. A consultant would be hired to determine the necessary modifications and community input would be brought in to this process.

How many people will the wind farm employ during the construction phase?

The initial construction phase will require 200-300 workers. Some of these jobs will go to local workers, but a significant number of the workers would come from off island.

Where will these people live while they are on Molokai?

Speaking at the Maunaloa MPL meeting, Parquet suggested refurbishing the abandoned hotel(s) owned by Molokai Ranch. He stated that this could accomplish two things: 1) The hotel rooms could provide accommodations for transit workers; 2) Upon completion of the project, the refurbished hotel(s) could resume tourist operations and offer employment. Parquet went on to state, “if this is something that the community wants.”

How many jobs will there be after construction is finished?

According to First Wind, the project would employ three operations and maintenance personnel and three wildlife biologists. Additionally, the turbine manufacturer would provide one maintenance technician for every 10 wind turbines. It is possible that qualified residents could be trained at other project sights in order to prepare them for work on Molokai.

Category: News, Sustainability

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  1. mkklolo says:

    If one windmill generates 40 decibels at a mile and one half…how much from 90 windmills? What will that be beyond our normally very low background noise level at night? Sounds carry for miles here at night. Has anyone not working for big wind tested these levels around actual working windfarms?

    OK, so they bond the removal of the windmills at today’s cost…when the time comes, it will probably remove one or two windmills and the rest will become part of the Molokai archeological record.

    Just the warf needs to be modified? How about the highways? Will the giant trucks be able to negotiate the turn at the end of the warf? What sort of vertical clearance do they need…will they clear our phone and power lines? Will they be able to play nicely with our regular barge deliveries and who gets priority? How much will traffic all along the route be disrupted?

    Why do we want to put up with all these problems so that Oahu can continue to gobble more and more energy, and when will they want to double the power coming from Molokai?

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