Source: National Renewable Energy Laboratory Photographic Information eXchange
Europeans used wind energy to sail to Virginia for 400 years, from the 1500's into the 1900's. Since those Europeans settled Virginia successfully in 1607, rural Virginians have used windpower to pull water up from wells - long before electrical lines connected farms to the "grid" and powered modern pumps. In some cases, wind power was also harnessed in Virginia to power manufacturing facilities, such as mills that ground wheat into flour. Pumping and powering grist mills required that the windmill be located directly next to the facility - gears and belts could not transmit the mechanical energy more than about 100 feet.
Today, almost all labor-saving devices in the home, office, or manufacturing plants operate off electricity that can be generated far away from the site where the power is used. A handful of existing wind turbines convert wind energy to electrical energy, including one 10 kW turbine at the Smith Mountain Lake Visitor Center:
More wind-powered turbines are planned. Demand for more electricity is expected to increase along with the state's population, despite intermittent efforts to conserve energy. The one-time infrastructure costs of building turbines and electrical transmission lines in remote areas is high, but the annual cost for fuel (wind...) is free. In addition, states are adopting Renewable Portfolio Standards that mandate a certain percentage of electricity generated or purchased within the state come from renewable sources, and urban regions with air quality problems (like Metropolitan Washington) are trying to get credit for purchasing "green power" to meet Clean Air Act standards.
The greatest potential for generating electricity from wind energy in Virginia is to locate turbines in the mountains (especially Highland County) and offshore (east of the Eastern Shore/Virginia Beach). Utilities seeking to generate electricity for sale look for at least Class 3 or higher zones, where wind speeds exceed 7 mph.
Windmills involve tall towers, so the projects involve scenic impacts. Wind speed next to the ground is reduced by friction with vegetation and the surface of the ground. However, 400 feet above the ground, the wind currents will be faster and steadier. A tall windmill has greater potential to convert wind energy into electrical energy, but a tall windmill will also be more visible from a distance.
Ridgetops in the Blue Ridge, Ridge and Valley, and Appalachian Plateau physiographic provinces - and the open water region off the Outer Continental Shelf - are clearly the areas with Class 3 and higher winds that could power a modern turbine. Raising the turbine above the trees on towers 150-400 feet tall increases the potential windpower that could be captured... but makes the turbines very obvious intrusions on top of forested mountain ridges. In addition, new transmission lines will require cutting new swaths through the forests, creating visual scars.
Offshore locations are atttractive locations because there are no forests, no trees to slow down the breeze. From a venture capitalist point of view, the ownership and permitting issues are also significant. Turbines are not cheap, and "time is money," so investors look for places where the delays in getting authorization to build will be minimized. Wind energy projects can be located according to financial and political reasons, as well as by simple physical geography.
There are no private landowners offshore, no land to lease or buy. Instead, Federal permits must be obtained from the Department of the Interior - Mineral Management Service. Previously the Corps of Engineers issued the permits, in order to manage the creation of new obstructions to navigation. Now MMS has the responsibility, reflecting their offshore responsibilities for oil and gas drilling and mining from the ocean seafloor.
Federal permits require an environmental analysis and a public comment process. The request for a Federal permit near Nantucket Island in Massachusetts became a hot political issue in 2005-2006, and the US Congress slowed down the proposed offshore wind farm there.
On land, the mountains of Virginia are the most attractive locations for electricity-producing wind tubines. Mountains channel the wind currents into gaps, and wind speed on the ridges is usually higher than in the valleys. Because the jet stream typically flows north of Virginia, windmills are feasible on low ridges in the northern part of the state. The closer to the North Carolina border, the higher the Virginia ridge must be to intercept strong and steady winds.2
Most wind energy projects in the mountains are located on private lands. Energy companies would rather pay a private landowner and go through a county planning process than request a permit from the USDA-Forest Service to place turbines on Federal lands. (In addition, wind energy projects intended to generate power for sale must get a certificate from the State Corporation Commission.)
In November, 2002, Winergy LLC proposed to build 271 wind turbines in the Atlantic Ocean, east of Accomack County at a site called Porpoise Banks 2. The company proposed to build enough turbines to generate 975 megawatts/hour, equivalent to the output from a nuclear power plant. When the Army Corps of Engineers advised that the location was sensitive to the military, Winergy shifted its area of interest to the ocean east of Smith Island, at the southern tip of the Eastern Shore.
However, all proposals for wind farms offshore from the Virginia coast remain just proposals, with no operating turbines. Locating turbines out of sight, offshore of the Atlantic coastline of Virginia, does not eliminate siting conflicts.
In addition to the constraints of finding a location in Virginia with sufficient energy to power turbines, two environmental constraints limit the potential location of new wind energy farms - the visual impacts of the towers and blades, and tendency of the blades to kill birds and bats migrating through the area.
Turbines could be "bird Cuisinarts." The Eastern Shore is a major stopping point on the Atlantic Flyway, and the Army Corps of Engineers must consider the potential impact on migratory birds before granting a permit for an offshore wind farm.
A proposal in 2005 to build turbines on a ridge in Highland County exposed the conflicts between tourism-based businesses and the those who support wind farms. One article in the local paper noted that Federal mandates for utilities to generate a certain percentage of their electricity from renewable sources (renewable portfolio standards or "RPS") would stimulate wind power projects, but some states are "wind poor."
In early 2006, Community Energy, Inc. revealed its interest in building a wind farm in Patrick County. As described in The Roanoke Times:5
|
The company is looking at ridges around the county, but it has focused largely on Belcher Mountain, near Meadows of Dan, and Bull Mountain, near Patrick Springs.
Officials expect the turbines would be comparable in size to those proposed in Highland, which, if built, would stand slightly taller than Roanoke's Wachovia Tower. The project will require approval from state and federal agencies, but because Patrick County has no zoning ordinance, the county's say extends only to whether it grants the company a building permit. On Monday, however, the Patrick County Board of Supervisors voted 3-2 to pass an emergency ordinance that would prohibit the construction of any structure more than 100 feet in height... |
Geographic Information System (GIS) technology can be used to identify environmentally-sensitive locations that would stimulate objections to a proposed wind energy "farm" of multiple turbines - see A Landscape Classification System for Virginia. Here is a sample map from that report:
