Since colonial times, wind has been utilized in Virginia for transportation, pumping water, and powering equipment. In the future, high-tech windmills may be assembled in wind farms on Virginia's mountains and offshore to generate electricity, helping utilities meet Renewable Portfolio Standards (RPS). The capacity of wind to generate electricity is now forcing local, state, and Federal officials to define what places are appropriate vs. "off-limits" for modern wind turbines.
For 400 years, from the 1500's into the 1900's, the Spanish, French, English, and other Europeans used the kinetic energy in wind to sail from Virginia back and forth to the Caribbean, Africa, or Europe.
until the Civil War, international transportation was based on wind energy
Source: Illustrated London News, The City Quay, Richmond (May 31, 1862)
Since the English settled Virginia successfully in 1607, rural Virginians also have used wind to draw water up from wells and 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. In Tidewater, windmills located on bluffs next to the river, as in Yorktown, could maximize the opportunity to catch a steady breeze.
windmill at Yorktown, shown on French map in 1781
Source: Library of Congress, map by Sebastian Bauman, 1781
"The old windmill tower at Yorktown much in disrepair prior to 1840"
Source: National Park Service, Yorktown's Main Street - Illustrations
Today, almost all labor-saving devices in the home, office, or manufacturing plants use electricity that is 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 10kW turbine at the Smith Mountain Lake Visitor Center.
traditional farm windmill, good for pumping water up from a well
Source: National Renewable Energy Laboratory Photographic Information eXchange
wind turbine designed to generate electricity
Source: National Renewable Energy Laboratory Photographic Information eXchange
More wind-powered turbines are planned in the mountainous regions of Virginia, and in the Atlantic Ocean east of the shoreline. Demand for more electricity is expected to increase along with the state's population. As more people are born in or move to Virginia, total demand for electricity in Virginia will climb - even if conservation efforts ultimately reduce demand/person.
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. Even though electricity generated by wind costs more than electricity generated from coal, hydropower, or nuclear facilities, there are still customers for wind-generated electricity.
In addition to Federal tax advantages, some states are adopting Renewable Portfolio Standards that mandate a certain percentage of electricity generated or purchased within the state come from renewable sources. Urban regions not in "attainment" with Clean Air Act standards (such as Metropolitan Washington) seek credit for purchasing "green power" to meet pollution standards.
Virginia has defined voluntary (but not mandatory) Renewable Portfolio Standards in the 2010 Virginia Energy Plan. The state's Renewable Portfolio Standard is limited to investor-owned utilities, so it excludes electric cooperatives, municipal utilities, and industrial co-generation plants. The standard also excludes nuclear energy from the baseline. The optional target is to obtain 15% of the remaining sources of electricity from renewable sources by the year 2025.1
Classification schemes to evaluate potential wind energy vary. A "Class 3" location by one organization might be categorized as "Class 6" by another scheme. The Virginia Wind Resource Map summarizes the wind potential of the state at 50 meters above the ground, in simple language:2
Ridges 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. The Piedmont and the Coastal Plain have few locations with high wind potential. The greatest potential for generating electricity from wind energy in Virginia is to locate turbines in the mountains (a proposed wind farm in Highland County received the first zoning approval in Virginia) 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 12.5 mph. (Wind power maps often show speeds measuring "wind density," where Class 3 speeds are about 15 mph. Wind density accounts for the decline in atmospheric density at higher elevation; thinner air generates less power when pushing against a turbine blade.)
The energy potential of a wind turbine increases dramatically as wind speed increases. The maximum energy output of a turbine at full speed is far greater than the likely production at average speeds... and the wind does not blow 24 hours/day, either.
Wind energy is often measured at 50 meters (164 feet) above the ground, but turbines on towers may be placed higher. Wind speed next to the ground is reduced by friction with vegetation and the surface of the ground. In engineering terms, "there is often a layer of high wind shear between 10 and 50m height above ground due to the influence of trees."3
To maximize wind speed that turns blades, windmills involve tall towers. If a turbine blade can be extended on a tower as much as 400 feet above the ground, the wind currents will be faster and steadier. The vertical distribution of wind speeds is not a simple "higher is always better" equation, but typically a tall windmill has greater potential to convert more wind energy into electrical energy, and produce more electricity at a lower cost.
However, a tall windmill will also be more visible from a distance; wind energy projects create scenic impacts. A turbine placed on a rooftop will not generate the same energy as a turbine on a 30-meter (100 feet) tower, but zoning in most residential areas blocks homeowners from building tall towers. Raising turbine blades far above 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.
Source: Virginia Wind Energy Collaborative: Virginia Wind Resource Map with VWEC Activities, Wind power density at 50 meters
Offshore locations are attractive locations physically because there are no forests, no trees to slow down the breeze. Wind energy projects can be located according to financial and political reasons, as well as by simple physical geography. 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. Offshore, companies can negotiate with just state/Federal governments to get rights to build towers with turbines.
There are no private landowners offshore, no land to lease or buy. Instead, Federal permits must be obtained from the Department of the Interior - Bureau of Ocean Energy Management (formerly known as the Minerals Management Service). Previously the Corps of Engineers issued the permits, in order to manage the creation of new obstructions to navigation. Now the Bureau of Ocean Energy Management has the responsibility, reflecting their offshore responsibilities for oil and gas drilling and mining from the ocean seafloor. The Federal government will lease 20 blocks in a 140,000 acre area designated for offshore wind turbines.
Federal permits require an environmental analysis and a public comment process. The request for a Federal permit for the Cape Wind project near Nantucket Island in Massachusetts was delayed for a decade by political disputes, with local residents and tourists concerned that offshore towers would alter the scenic vistas that made Nantucket special. That long delay rippled throughout the wind industry, affecting the willingness of lenders to finance other projects, until the Federal government decided to approve offshore wind farms there.
In 2013, North Carolina tourism officials were alarmed by a proposal to lease enough space for up to 1,000 turbines, with the potential that rows of industrial towers would be as close as six miles from the Outer Bank beaches. Vistas would be affected, especially at night when red aircraft warning lights would blink constantly. The Kitty Hawk Town Council made clear its opposition to any towers closer than 20 miles. At the same time, the Virginia Port Authority requested any wind towers off the coast be located as close as possible to the coastline, to reduce the navigation challenges for 5,000 ships crossing the Outer Banks wind zone each year.4
All proposals for wind farms in ocean waters create potential conflicts with shipping along the coast, including the slow-to-maneuver aircraft carriers base at Norfolk Naval Base. In addition, military radars on the coastline may be affected by wind turbine blades, though some companies are developing "stealth" turbines that would not block radar signals.
Locating a wind farm off the Virginia coast is a complex challenge. One factor to consider is how to bring the electricity to market, onshore. An offshore wind farm near Virginia Beach/Norfolk would be closer to more customers than a wind farm located off Chincoteague, reducing costs for underwater transmission lines and upgrading power lines onshore.
the potential for wind-powered energy at speeds greater than 7.5 meters per second (over 16 miles per hour) increases away from the shoreline - but so does the cost for any underwater power transmission line
Source: Bureau of Ocean and Energy Management, Exploring Ocean Wind Energy
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:
On land, the taller mountain ridges in Virginia are the most attractive locations for electricity-producing wind turbines. 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 in all four seasons of the year:5
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 National Forest lands. (Wind energy projects intended to generate power for sale must also get a certificate from the State Corporation Commission.) Those Federal forests have existing stakeholders and land use plans that defined primary uses for specific areas, and changing the designated uses to include wind turbines is a difficult process.
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.
Locating turbines out of sight, offshore of the Atlantic coastline of Virginia, does not eliminate siting conflicts. All proposals for wind farms off the Virginia coast remain just proposals, with no operating turbines.
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," when a flock migrates through a wind farm. The Eastern Shore is a major stopping point on the Atlantic Flyway, and the Federal government must consider the potential impact on migratory birds before granting a permit for an offshore wind farm.
Birds and bats are threatened by onshore wind farms as well. A proposal in 2005 to build turbines on a ridge in Highland County exposed the conflicts between tourism-based businesses and those who support wind farms. Multiple lawsuits were finally resolved in 2007 in favor of Highland County's rezoning. The wind farm, which would be the highest in the United States at over 4,200 feet, could have 20 towers as much as 400 feet tall... but after the approvals were finalized, nothing was built.7
Even within states with the climate and topography to generate a lot of wind energy, the locations for windmills are often in rural areas - requiring unsightly power lines to the urban areas creating the demand for power. As discussed in the Congressional debate:8
In early 2006, Community Energy, Inc. revealed its interest in building a wind farm in Patrick County. The immediate result was a decision by the local officials to tighten zoning restrictions, to ensure a special review process would be required and a wind farm could not be constructed without clear approval from the county:9
electricity costs more in the Northeast, so offshore wind farms could end up exporting energy to New York customers while affecting tourism of coastal communities in Virginia/North Carolina
Source: Southeastern Coastal Wind Coalition, Why North Carolina and the Southeast?
A 2010 proposal by Invenergy Wind Development to build 135-meter high towers (443 feet) on Poor Mountain in Roanoke County generated conflict regarding the noise/visual impacts vs. economic/environmental benefits of wind-generated electricity. The Roanoke Group of the Sierra Club conditionally endorsed the project, acknowledging that the benefits of generating renewable energy at the site outweighed the predicted environmental impacts. Landowners objected to the towers, and Invenergy chose to delay rather than construct the project.10
In 2010, Governor Bob McDonnell articulated a goal of making Virginia the "energy capital of the East Coast" and included windpower in his plans. Research and planning for offshore wind projects were starting to be followed by investment, with the expectation that wind-generated electricity can compete with traditional sources - especially if coal prices climbed, as international customers such as China increased demand for coal faster than mines could increase supply.
Then the fracking boom increased supplies of natural gas and energy prices dropped. By 2015, there were still no commercial wind farms in Virginia, but a company did propose the Rocky Forge Wind Project on North Mountain near Eagle Rock. If built, up to 25 turbines could reach up to 550' high - which would exceed the height of the tallest building in downtown Roanoke. Botetourt officials responded by preparing a local ordinance for siting wind towers, giving county official a role in determining how close turbines could be located to houses and how much their noise must be controlled.11
the proposed Rocky Forge Wind project could link to the grid through existing electrical transmission lines (red line) at the southern end of North Mountain
Source: ESRI, ArcGIS Online
The Virginia Coastal Energy Research Consortium calculated that offshore wind farms could generate electricity at a rate competitive with coal-fired power plants, if the facilities using fossil fuel were required to implement carbon capture and sequestration to offset the global warming impacts of carbon dioxide.
In 2018, offshore wind is projected to cost 22 cents/kilowatt hour, compared to 10-11 cents/kilowatt hour for electricity generated at nuclear or conventional coal/natural gas plants.14
The more powerful the wind, the lower the cost to generate electricity from wind turbines. Working from the shoreline near Cape Henry, NASA's Langley Research Center in Hampton has used Doppler LIDAR to map the wind speeds in the 20 different blocks in the area to be leased by the Federal government.
In March 2011, the Virginia Marine Resources Commission approved a site in state waters three miles west of Cape Charles for a 5MW offshore wind turbine prototype to be constructed by a Spanish energy company, Gamesa. A month earlier, the same company opened an offshore turbine factory in Norfolk. A competing firm, Poseidon Atlantic, also announced plans to build 10 test pads on the Eastern Shore to test and certify wind turbines on towers as much as 750' high, which is the maximum height authorized in Northampton County.15
However, 14 months later Gamesa abandoned its plans for Virginia's first prototype offshore windmill and chose instead to build in the Canary Islands. Though Virginia state agencies had green-lighted all permits quickly, the company may have been spooked by unclear Federal policy regarding subsidies for renewable energy and by the threat of competition from power plants fueled by low-cost natural gas.16
Gamesa planned to lease submerged land from Virginia and build its (now-cancelled) prototype offshore wind turbine in the Chesapeake Bay between Cape Charles and the middle Peninsula
Source: Virginia Joint Permit Application and Project Description for Gamesa G11X Offshore Wind Turbine Project
In 2012, the intergovernmental Virginia Renewable Energy Task Force identified 113,000 acres off the Virginia coast, defined in 32 specific blocks of ocean between 23.5-35.5 nautical miles east of Virginia Beach, as the prime area for future wind farm leases. The initial Federal review started with 70 square blocks, 3 miles on each side.
After excluding areas with potential conflicts with Department of Defense activities (including dredge disposal regulated by the U.S. Army Corps of Engineers), NASA operations from Wallops Island, and shipping paths (including the Coast Guard's Atlantic Coast Port Access Route Study) - but still including a fish haven/artificial reef - the Bureau of Ocean Energy Management narrowed the area of potential leasing to 19 complete blocks and 13 partial blocks. The site offered potential for installing enough turbines to generate 2,000 megawatts.
The Federal government sold the rights to build a wind farm on the 113,000 offshore acres in 2013. There were eight qualified bidders, but only two companies actively bid. As expected, Dominion Power (which already has electricity distribution and sales infrastructure onshore) won the auction, and its price of over $14/acre was well above the minimum opening bid at $2/acre.
Dominion Power, the dominant energy utility company in Virginia, received a $47 million Federal grant for the Virginia Offshore Wind Technology Advancement Project (VOWTAP). The utility announced plans to build two 6-megawatt turbines, each 500-feet tall, to help plan the construction of up to 200 similar turbines to fully develop the wind potential on the 113,000 acre parcel leased from the Federal government.17
Some environmental groups such as the Sierra Club feared Dominion Power would avoid developing its offshore lease and stretch out development as long as possible. Delay could minimize innovation and reduce the potential for offshore wind turbines out-competing traditional coal-fired and gas-fired power plants, in which Dominion has invested heavily.
That "delay offshore wind" theory assumes Dominion Power would prefer to build more fossil-fueled plants, rather than develop the technology required to reduce the costs of wind power. Dominion's announcement in April, 2015 that it was postponing plans to build the two test offshore turbines due to unexpectedly high construction costs led to accusations by the Virginia League of Conservation Voters that the utility was "dragging its feet."18
Another scenario is that the General Assembly could determine it is in the public's interest to support offshore wind energy. The State Corporation Commission (SCC) could then authorize Dominion to increase its rates to recover the additional cost, if wind-generated electricity costs more than electricity generated at a gas-fired power plant. The General Assembly has previously passed legislation declaring that construction of the coal-fired Virginia City Hybrid Energy Center was in the public interest, and that construction of solar energy projects generating up to 500 megawatts was also in the public interest.19
It would be out of character for the SCC to require Dominion to absorb additional costs and reduce the profits of the private utility. If the two 6-megawatt turbines demonstrate that electricity generated by offshore wind is not competitive with electricity generated from other fuel sources, then the SCC could decline to authorize rate increases to recover investment in additional turbines and the large-scale wind energy project in the Atlantic Ocean would stall.
In the best case scenario for sustainable energy advocates, research will demonstrate electricity from wind will drop below the costs to generate electricity from fossil fuels, Dominion Power will build a large wind farm by 2018, and existing power plants that create carbon dioxide and other pollutants will be closed.
If wind, solar, or other new alternative fuel technologies could out-compete fossil fuels and nuclear power quickly, then Dominion Power might have to close existing power plants before the end of their useful life. In the worst case scenario for the utility shareholders, the SCC would not approve rate increases to offset the "stranded costs" of prematurely-closed facilities, reducing the value of Dominion Power's stock.
Such a scenario would require rapid development and implementation of wind, solar, and other technologies and/or substantial reduction in the demand for electricity through conservation, with a transformation of the electrical generation system in 10-30 years. If widespread adoption of alternative fuels could be delayed for several decades, then Dominion Power could amortize its investment in existing power plants by the year 2050 at the latest.
Wind farms may have benefits beyond a reduction in use of fossil fuels. In theory, wind farms in the Atlantic Ocean could absorb energy from storms and reduce the impacts onshore of high winds and storm surges.
A massive number of turbines (over 400,000) along the East Coast could redirect the power of a storm, reducing wind speeds by over 80mph and protecting urbanized areas such as Norfolk. No one has proposed building that many turbines - the expected number in the Outer Continental Shelf Offshore Virginia block was just 200 - but offshore structures offer an alternative to investing billions of dollars for hardening the shoreline:20
the cable transmitting electricity from wind turbines in the Atlantic Ocean (24 miles east Virginia Beach) will come onshore at Camp Pendleton, south of the resort area
Source: Dominion Power, Virginia Offshore Wind Technology Advancement Project - Preferred Cable Landfall and Interconnection Site
Base map from US Geological Survey (USGS), Virginia Beach 7.5x7.5 topographic map (2013)
after the Civil War, windmills in Northampton County were abandoned and the sails rotted away
Source: Library of Congress, A Peninsular Canaan in Harper's New Monthly Magazine (May 1879)
Poor Mountain southwest of Roanoke
showing planned locations of up to 18 turbines on ridgetops
Source: Invenergy Wind Development, Poor Mountain Site Map
References1. "The Virginia Energy Plan," Department of Mines, Minerals and Energy, July 1, 2010, http://www.dmme.virginia.gov/DE/VAEnergyPlan/2010-VEP/VEP-2010.pdf/a> (last checked October 17, 2011)
2. Department of Energy - Wind Program and the National Renewable Energy Laboratory, "Virginia Wind Resource Map," www.eere.energy.gov/windandhydro/windpoweringamerica/maps_template.asp?stateab=va (last checked June 11, 2006)
3. Wind Resource Maps of Virginia, 2002, p.3, vwec.cisat.jmu.edu/documents/Virginia%20Wind%20Mapping%20Report.pdf (last checked November 5, 2009)
4. "Outer Banks offshore wind farm plan gets blowback," The Virginian-Pilot, June 16, 2013, http://hamptonroads.com/node/680636 (last checked June 16, 2013)
5. Wind Resource Maps of Virginia, p.2
6. Alliance for the Chesapeake Bay, Chesapeake Bay Journal, "Wind turbine proposals for Atlantic Coast face challenges," January/February 2003, www.bayjournal.com/article.cfm?article=727(last checked June 11, 2006)
7. "Wind farm approved for rural Virginia mountain range," the Roanoke Times, December 28, 2007 (last checked October 17, 2011)
8. "Congress takes up debate on wind energy," The Recorder, June 23, 2005 www.therecorderonline.com/index.php?id=145 (last checked June 11, 2006)
9. "Wind may be asset in Patrick County," Roanoke Times, April 14 2006, www.roanoke.com/news/roanoke/wb/xp-60907 (last checked June 11, 2006)
10. "Opposing winds: Feelings about Poor Mountain wind farm might depend on proximity to turbines," The Roanoke Times, June 12, 2011 http://www.roanoke.com/news/roanoke/wb/289595 (last checked October 17, 2011)
11. "Botetourt County to consider wind turbine ordinance," The Roanoke Times, February 8, 2015, http://www.roanoke.com/news/virginia/botetourt-county-to-consider-wind-turbine-ordinance/article_8f3cb722-e422-59fa-b9c5-87d1dda5c3da.html; "Wind turbine company seeks Botetourt County's approval for test towers," The Roanoke Times, July 29, 2015, http://www.roanoke.com/news/virginia/wind-turbine-company-seeks-botetourt-county-s-approval-for-test/article_7dcd5e3f-614e-5aad-b7bd-b2acbf94c9c8.html (last checked July 30, 2015)
12. "Virginia Offshore Wind Studies, July 2007 to March 2010: Final Report," Virginia Coastal Energy Research Consortium, 20 April 2010, http://www.vcerc.org/VCERC_Final_Report_Offshore_Wind_Studies_Full_Report_newest.pdf (last checked October 17, 2011)
13. "Dominion pushes for large wind farm off Va. Beach," The Virginian-Pilot, February 2, 2012, http://hamptonroads.com/2012/02/dominion-pushes-large-wind-farm-va-beach (last checked February 2, 2012)
14. "Entire industry faces headwinds," Hampton Roads Business Journal< May 23, 2014, http://insidebiz.com/node/395671 (last checked May 26, 2014)
15. "Will laser tests lead to windmills?," Newport News Daily News, October 17, 2011, http://www.dailypress.com/news/hampton/dp-nws-nasa-laser-wind-20111017,0,6608892.story; "Agenda March 29, 2011," Virginia Marine Resources Commission, http://www.mrc.state.va.us/Commission_Agendas/ca0311.shtm; "First U.S. Offshore Wind Turbine Factory Opens in Virginia, But Has No Customers Yet," Inside Climate News, Feb 17, 2011, http://insideclimatenews.org/news/20110217/first-us-offshore-wind-turbine-factory-opens-virginia-has-no-customers-yet; "Offshore wind turbine test center planned for Eastern Shore," Newport News Daily Press, October 13, 2011 http://www.dailypress.com/news/science/dead-rise-blog/dp-offshore-wind-turbine-test-center-planned-for-eastern-shore-20111013,0,467112.story (last checked October 17, 2011)
16. "ANALYSIS: Why Did Gamesa Abandon Virginia?," Offshore Wind Wire, May 17, 2012, http://offshorewindwire.com/2012/05/17/analysis-why-did-gamesa-abandon-va/ (last checked July 23, 2012)
17. "Commercial Leasing for Wind Power Development on the Outer Continental Shelf (OCS) Offshore Virginia - Call for Information and Nominations," published in Federal Register, February 3, 2012, by Bureau of Ocean Energy Management, http://www.boem.gov/uploadedFiles/BOEM/Renewable_Energy_Program/State_Activities/VA%20Call%20for%20Information.pdf; "Atlantic Wind Lease Sale 1 (ATLW1) Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Virginia - Final Sale Notice," Bureau of Ocean Energy Management, Federal Register, Vol. 78, No. 141 (July 23, 2013), http://www.boem.gov/VA_Final-Sale-Notice_Signed/; "Dominion Virginia Power Wins Federal Offshore Wind Auction," Dominion news release, September 4, 2013, http://dom.mediaroom.com/2013-09-04-Dominion-Virginia-Power-Wins-Federal-Offshore-Wind-Auction; "Dominion wins bid for wind farm, environmentalists wary," Newport News Daily News, September 5, 2013, http://www.dailypress.com/news/breaking/dp-nws-offshore-lease-sale-20130905,0,6831925.story; "Waters off Va. Beach chosen for wind turbine project," The Virginian-Pilot, May 8, 2014, http://hamptonroads.com/node/715700 (last checked May 8, 2014)
18. "Tell Dominion to Support Offshore Wind," Virginia Chapter Sierra Club, http://action.sierraclub.org/site/PageServer?pagename=TellDominiontoSupportVAOffshoreWind; "Dominion: Offshore wind turbines too expensive," The Virginian-Pilot, April 24, 2015, http://hamptonroads.com/2015/04/dominion-offshore-wind-turbines-too-expensive (last checked April 24, 2015)
19. "Jaffe: In Virginia, signing on to Earth Day," The Virginian-Pilot, April 24, 2015, http://hamptonroads.com/2015/04/jaffe-virginia-signing-earth-day (last checked April 24, 2015)
20. Mark Z. Jacobson, Cristina L. Archer, Willett Kempton, "Taming hurricanes with arrays of offshore wind turbines," Nature Climate Change, February 26, 2014, http://doi.org/10.1038/NCLIMATE2120; "Wind turbines could weaken hurricanes, study shows," The Virginian-Pilot, February 28, 2014, http://hamptonroads.com/node/708371 (last checked February 28, 2014)
a twisted jacket foundation will be less expensive for Dominion Power's two wind turbines, 26 miles offshore
Source: Department of Energy, Advanced Offshore Wind Tech: Accelerating New Opportunities for Clean Energy