Like prospectors who discovered gold in the old West, developers, business owners, and homeowners are rushing to stake their claims to free, renewable energy by putting up wind turbines.

As more of the structures sprout, however, local, state, and federal authorities are struggling to close the gap between old regulations and relatively new technology.

On Martha's Vineyard, there is no standard Island-wide town bylaw regarding wind turbines.

Although Aquinnah currently has no wind turbine bylaw, the structures are ruled out by zoning restrictions on building heights and sites.

Last August, however, voters at a special town meeting said yes to the possibility of a municipal renewable wind energy program and the possible construction of a wind turbine on town-owned land.

After receiving favorable responses from residents to a questionnaire about wind energy, Aquinnah's planning board has been working on a new wind bylaw. Board member Carlos Montoya said this week that the town plans to hold two public forums in August to present the bylaw to voters for discussion. After considering comments, the planning board will hold a hearing on the final version of the bylaw to put before voters as a warrant article at a special town meeting.

In Chilmark, the planning board is reviewing the town's zoning bylaws, which address windmills under "accessory uses." Conditional provisions restrict tower climbing access and require a recommendation by the site review committee as to the height and siting of a windmill. The board of appeals determines whether the proposed height and location of the windmill interferes with the "rights of abutters to enjoy their property." Wind turbines are not addressed in Chilmark's current bylaws regarding districts of critical planning concern.

Edgartown enacted a wind bylaw that conditionally allows by special permit the use of "wind energy conversion systems." The bylaw requires a minimum setback distance for the wind turbine equal to the maximum tip height (MTH) of the wind turbine, plus 20 feet from any neighboring property line.

The bylaw restricts tower climbing access and requires the applicant to demonstrate that the turbine will not cause excess noise or interference with local television and radio reception.

In zoning bylaws for Oak Bluffs, a section on special regulations states that "a windmill is allowed as of right," provided it meets certain conditions. The setback requirement is the same as Edgartown's. Oak Bluffs limits tower height to 70 feet from grade to the center of the rotor and the diameter of the rotor to no more than 35 feet. Anything else requires a special permit from the Board of Appeals.

Tisbury's zoning bylaws prohibit windmills, which fall under the description of "slender structures," in excess of 80 feet in height above the mean natural grade of the lot and adjacent lots. In residential areas, wind turbines higher than 40 feet require a permit from the Board of Appeals, as do those in the business district that exceed 80 feet in height. There is also a setback requirement.

West Tisbury allows wind turbines that exceed applicable height limits, provided they comply with setback requirements. A planning board subcommittee currently is working on a wind turbine zoning bylaw that would require an applicant to apply for a special permit requiring neighbor notification and an advertised public hearing. Under the proposed new bylaw, a wind turbine special permit also would require approval by a two-thirds majority vote at town meeting before it would be granted.

The variations in town zoning bylaws that pertain to wind turbines are not unique to Martha's Vineyard. At the state level, the Massachusetts Division of Energy Resources has prepared a model amendment to a zoning ordinance or bylaw as an example for towns. Closer to home, the Cape Cod Commission and Cape Light Compact also prepared a model bylaw, funded by a grant from the Massachusetts Technology Collaborative. Martha's Vineyard Commission (MVC) staff member Bill Veno helped review the document and provided comments.

Among key permits and approvals at the Federal level, the Federal Aviation Administration's (FAA) determination of no hazard to air navigation (DNH) is the most crucial for many wind turbine projects within a certain radius of an airport. Any turbine more than 200 feet above ground level requires a DNH application to the FAA.

On an island the size of Martha's Vineyard, while some properties may not seem close in proximity to the airport, they may be close to a flight path.

Other environmental assessments and considerations include a radio spectrum transmission analysis to identify if proposed turbine locations will interfere with communications transmissions. Depending on where a site is located, the U.S. Fish and Wildlife Service may require a threatened and endangered species assessment.

At the state level, larger projects may require a Massachusetts Environmental Policy Act (MEPA) review and impact assessments of endangered species and migratory birds by the Massachusetts Department of Environmental Protection.