A wind developer that became a "lightning rod" for the industry when one of its turbines started shedding ice in December, has revealed its latest strategy for dealing with ice build-up, writes Rachel Johnson. ..."We knew icing would occur but believed our turbines would stop in the event of an ice build up," he said. The investigation revealed that the most widely available guidelines on icing, including those from the BWEA, had said that wind turbines are designed to shut down in the event of an ice build up.

Even when it comes to the giant blades of the turbines in Amaranth and Melancthon, there might be truth in the old expression that "it's an ill wind that blows no good." This might have been the case when the Melancthon I wind project had to be shut down for nine days in December 2006 because of an ice storm and the resultant imbalance of the blades.

A sensor which should switch off a wind turbine in icy conditions has failed - for the second time. As reported in The Evening Telegraph last week, a faulty sensor on the turbine in King's Dyke, Whittlesey, was blamed for huge shards of ice flying off its blades and crashing into homes and gardens in November. ..."The turbine was shut down immediately after we were alerted, and will remain in this state until further notice."

A Meridian Energy witness was scrutinised for not considering Central Otago's harsh winter, which could shut down wind turbines in times of high demand. The Environment Court hearing into the $2 billion Project Hayes windfarm continued yesterday with wind energy consultant Graham White appearing for Meridian. He said in freezing humid condition wind turbines could ice up and no longer operate.

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.

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.

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."

A wind turbine has been switched off and an investigation launched after its frozen blades showered nearby homes with large chunks of ice. Residents complained when the 260ft wind generator began hurling shards of ice, some measuring two feet long, after the cold snap over the weekend.

Residents were left fearing for their safety after shards of melting ice fell on homes and gardens from the blades of a giant wind turbine. For about four hours people in King's Dyke, Whittlesey, had to take cover as huge lumps - some two feet long - showered them from the 80 metre high tower on Saturday morning. Resident Peter Randall, whose son's house lies a stone's throw away from the turbine, said: "Somebody is going to get killed. There was huge lumps of ice shooting off and landing everywhere.

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 pros and cons of building wind turbines near public roads took center-stage at last week's Grant County Commission meeting.

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.

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.

Professor Terry Matilsky, associate professor of physics and astronomy at Rutgers University, addresses the kinetics of ice throw.

An eight-day shutdown of Melancthon 1 wind turbines was undoubtedly costly but is being viewed by industry officials as among statistically and meteorologically predictable occurrences for any wind plant. The turbines were shut down when ice formed on the blades during the ice storm of Friday, Dec. 1, and came back online only after the ice had thawed from the blades at some point late Sunday.