A faulty sensor on a giant wind turbine is being blamed for huge shards of ice flying off its blades and crashing into nearby homes and gardens. As The Evening Telegraph reported in November, residents in King's Dyke, Whittlesey, had to take cover for more than four hours when huge lumps of ice, some measuring 2ft, were flung from the giant machine's blades.

During a recent roundtable discussion concerning wind power projects at the Delaware County Historical Society a participant affiliated with two local wind development companies stated that there were three issues where the health and safety impacts were predictable and avoidable---- ice throws, noise, and flicker. Since the statement was made in the presence of planners who are advising towns in the process of writing regulations to protect the health and safety of residents, I felt that a fuller discussion of the known science of these issues was important, and have prepared this report to that end.

Editor's Note: Dr. Jaffe's presentation to the Town of Meredith Planning Board on the proposed industrial wind plant vis-a-vis Meredith's 'vision' is available via the link below.

ICE forming on wind turbines can fly off, posing a potential danger to passing walkers in "exceptional" weather conditions, ScottishPower has admitted.

"Developers and owners of wind turbines have a duty to ensure the safety of the general public and their own staff. However, there are currently no guidelines for dealing with potential dangers arising from ice thrown off wind turbines. This puts developers, owners, planning authorities and insurers in a difficult position. To rectify this situation, the work presented here has commenced in order to produce an authoritative set of guidelines. Initial work has resulted in the development of a risk assessment methodology which has been used to demonstrate that the risk of being struck by ice thrown from a turbine is diminishingly small at distances greater than approximately 250 m from the turbine in a climate where moderate icing occurs."

The chair of the Yukon's energy corporation says wind energy isn't viable for the Yukon.

The chair of the Yukon's energy corporation says wind energy isn't viable for the Yukon. Willard Phelps told the territory's legislature last week the multi-million dollar experiment in wind power turbines had failed to produce the results the company needs.

The chair of the Yukon's energy corporation says wind energy isn't viable for the Yukon.

The failure of a sensor to halt a giant wind turbine when temperatures fall is blamed for shards of ice crashing into nearby homes in Cambridgeshire. The Cornwall Light and Power 80m (262ft) turbine was put up in August, near an industrial estate and close to homes in King's Dyke, Whittlesey. On 29 November chunks of ice started crashing into gardens.

Dominion Power and the Grant County Commission responded to a Mount Storm resident's concerns about the potential for ice on the blades of wind turbines this winter. Bruce Halgren of Mount Storm appeared before commissioners Jim Wilson, Charlie Goldizen and Jim Cole Tuesday. He said that he is concerned that the proximity of some of the NedPower wind turbines being constructed along Grassy Ridge Road could present a safety hazard to motorists from ice and debris being thrown off by the turbine blades in the wintertime.

A “highly unusual” combination of weather conditions forced Canadian Hydro Developers (CHD) to shut down all 45 wind turbines in the Melancthon I plant at a time when many residents of Dufferin County were experiencing a blackout, and they remained out of service Wednesday. “The severe weather experienced on Friday (Dec. 1) caused heavy ice buildup on the blades at the Melancthon wind plant,” said Project Manager Geoff Carnegie.

Editor's note: This short document prepared by personnel at the Wind Application Engineering Group of GE Energy provides some insight into the risks of ice throw. The content of this document confirms that ice fragments can be thrown large distances from the turbines.

This short GE Energy document explains the risk of ice build-up on the turbines and any mitigation. Note, the document acknowledges the risk of ice-shedding as well as ice-throw. An excerpt is included below. The full document can be accessed by clicking on the link.

Here is a reprint of an email about ice throw at Green Mountain Power's Searsburg wind energy facility in Searsburg Vermont. The email was written by John Zimmerman to an American Wind Energy Association listserv in 2000. Mr. Zimmerman managed the development of the Searsburg facility

The wind industry concedes that, as with all tall things (buildings, for example, or trees), ice and snow can build up and, eventually, fall down, creating a hazard to people and structures below. But the industry denies that "ice-throwing" - another concern surrounding wind power - is a problem. ...But a 2006 publication by G.E. Energy, a maker of large wind turbines, warns that "rotating turbine blades may propel ice fragments some distance from the turbine - up to several hundred meters if conditions are right."

3.8 Health & Safety

Affected Environment, Environmental Impacts and Mitigation Measures

"A number of comments submitted for the scoping process for the Desert Claim project EIS addressed concerns relating to potential health and safety issues. Specific topics indicated in these comments included certain possible hazards that are uniquely associated with wind turbines, such as blade throw and ice throw; health and safety issues associated with electrical and magnetic fields; more common hazards such as fire; and the incidence and impacts of shadow flicker, another phenomenon specific to wind turbines. Section 3.8 addresses these wide-ranging health and safety topics that have been identified as concerns for the environmental review. "

Ice throw is a concern related to the fact that any object at the end of the rotating blades is traveling at a high rate of speed. In the case of a 60 meter turbine (about 200’ diameter), rotating at 20 RPM, the tip of the blade is traveling at just over 140 mph. If the turbine diameter increases to 80 meters, the tip speed increases to just over 187 mph. There are reports of ice having accumulated at the tip of the turbine and upon breaking loose, traveling significant distance......

The reception was somewhat on the chilly side, Tuesday, when a pair of mountaintop residents brought their protests about windpower electricity to the Grant County Commission. Residents Bruce Halgren and Richard Spicer appeared before commissioners as part of a campaign to reduced the number of windpowered turbines being erected in the community by NedPower and Shell Renewables and Hydrogen. The pair asked commissioners to oppose six turbines to be constructed within 820 feet of public roadways. They say the turbines present an "ice throw" hazard to motorists on Grassy Ridge Road and state Route 93.

"Today, the task before the Joint Committee (regarding Bill S40) is to hear from the public on what would appear simple

- the giving and taking of “driveway” easements between the Commonwealth’s Wachusett Reservation (Stagecoach Trail) and the Town of Princeton’s legal “right of way” for its wind power site. As well, the town is offering the to transfer to the Commonwealth, ownership of, five acres of their 16-acre wind site.

I urge the Joint Committee for Bill S40 to carefully consider the following with regard to your recommendations an for easement exchange and accession of land from Princeton:

1. The Wachusett Wind Site is a 16 acre parcel wholly surrounded by the Wachusett Reservation and flanked within few feet, on three sides, by the well traveled Midstate, Harrington and Stagecoach trails. This portion of the state park is accessible and popular.

2. The present eight windmills are 120-feet high and are proposed to be replaced with two windmills as high as a 35- story building and with blades that stretch as wide as a football field - windmills whose elevation will come with 150- feet of the mountain’s elevation.

3. In the wintertime Wachusett experiences unusual ice storms in number and severity

4. In the wintertime, the windmills accumulate ice - then release it when it melts and falls, when it is blown off by wind or is thrown it off by the rotating blades

5. This ice has put holes in the roofs of utilty buildings on the wind farm and scattters itself across the fully accesssible wind site, the state reservation and hiking trails, threatening state park viisitors The risk associated with being struck windmill ice can be quantified and is relative to one’s distance from the windmills and will increase geometrically with the proposed windmills.

6. Windmills and wind data collection towers at Wachusett have structurally failed five times in twenty years on the Town of Princeton (PMLD) site. This also threatens the state park visitors as well with collapsing metal structures and flying blades. Proposed windmills and data towers will not be installed in compliance withthe manufacuturer’s recommendations and safety warnings."......

BEAR CREEK TWP. – Hiking trails around Crystal Lake could be ideal for snowmobiling and cross country skiing now that Luzerne County owns the property, purchased with public money for the purpose of preservation and recreation.