He says that it is clear from the consultants

Search Menu Search News Blogger Jobfinder newspaper Course fireplace ideas Guide Events Cultural Heritage fireplace ideas Insights Follow Focus Fehmarn connection Rejsekortet Toxic fluorine compounds Large Hadron Collider (LHC) Ice core drilling in Greenland Ebola epidemic Pihl and Son bankruptcy gene sequencing Atom Scrap IC4
Comparison of 11 years of production data from all wind turbines in Denmark combined with model wind data revealed surprising deterioration of older wind turbine energy production. By Sanne Wittrup November 1, 2013 at. 11:40
It put the director and engineer Per Nielsen from the consulting firm EMD International decided to find out - after a few Scottish reports had found annual reductions of 1.6 per cent. in wind turbine production.
EMD International prepares in advance on a monthly basis, an inventory of wind energy - called wind index - based on production data from all the country's wind turbines in conjunction with wind measurements from a number of stations. So data from 3,128 wind turbines with more than ten years in the business was at hand.
"On a monthly basis drown so small fall in production, but over 11 years, we could look at the numbers that half of the wind turbines actually increased their production and half deteriorated in relation to the wind index. Since an increase of course is unrealistic, there had to be something wrong with our wind index, "explains Per Nielsen.
Wind index has now been corrected so that half of the 3,128 turbines generate unchanged, while the other half loses 1.2 percent. production per year. So after 11 years as much as 12 per cent. less electricity than when the mill was new.
According to Per Nielsen, a portion of the decrease in wind turbines available in the study because a large part of the turbines is 600-750 kW turbines, which had gear problems after 6-10 years of operation, which gave a lot standstill and thus reduced available.
The second reason is the terrain changes because trees grow up, and built several houses - something that gives greater roughness and thus less wind in the terrain. Obviously it is a particular problem for wind turbines inland, while wind turbines near the sea does not lose production for this reason.
The analysis also mentions a fourth reason, which is not considered to be general: it measures the error. According to Per Nielsen, it is not a general error, but there are seen examples of errors in current transformers, which feed into the billing meters, allowing for low registered production.
Wear on the wings is the most serious problem for older wind turbines in Denmark today. It is available on all turbine types where the surface slides in varying degrees of salt, wind and sun, and it affects production, "he explains, adding that one does not know exactly how much production is affected by this cause.
He says that it is clear from the consultants' supervision, that there has been a deterioration of the durability of the wing surfaces, after being in the middle of the 1990s changed the coating out with a less slippery surface.
"We now call on all mill owners to go out and inspect the wings and find out how things stand. fireplace ideas There is, for example, certain laminated blade types, as we know, is hard infested, and which in time can be a security risk, "said Strange Writes.
Overall, says Per Nielsen, the figures point to a new and underestimated the market fireplace ideas for manufacturers 'after-sales products' that can boost production fireplace ideas at the aging mills. For example, in the form of improvements to the aerodynamics fireplace ideas of the wings: fireplace ideas
"It has not previously been aware of the year with declining production - and have not been able to quantify how much is possible. is to download. But with the new index will mill grinder better able to assess how much is to be gained fireplace ideas by bringing the mill up to date, "he said. Logically, with some decline
Technology fireplace ideas Manager Henrik Stiesdal from Siemens Wind Power is not quite as surprised decline fireplace ideas in production for the older mills, although he had assumed a somewhat lower level of 2-5 percent over a period of about ten years:
"It is logical fireplace ideas that buildings and several trees takes the wind, and outage or disposal is to a great extent a question of which service you have. And what the technical demotion fireplace ideas for example, the wings are concerned, it has referred more important for older wind turbines fireplace ideas because the wings are stall-regulated, why blades condition and efficiency are important fireplace ideas in turbine maximum power, "he said.
Yet he believes that the new analysis, which he calls 'an impressive piece of work' is essential knowledge to deal with when working with the development of wind turbines, although it does not give rise to acute changes of technologies or practices:
"We are working already fireplace ideas to make wind turbine blade surface fireplace ideas more resistant to erosion and damage from for example sand. The surface is designed for wind turbines in the desert, but we are considering introducing it on all our wind turbines with a view to the future. An analysis as the current can help to shape our