Roskilde Music Festival: Mobile wind turbine version 2.0
“Last year, our turbine had stronger legs. They were made of aluminium, but it was still bothersome to handle and very heavy to carry. The actual pole was much thicker, and then we had a number of earth rods which took 20 minutes to bury. The whole thing was tremendously oversized and actually ten times stronger than what was needed,” he says.
“We used the platform provided by the rather harsh environment at Roskilde Festival as well as the many data that we brought home with us to further develop the wind turbine into a completely new model. Now it weighs a third of the original—around 10 kg—and is much easier to install. The safety factor has been improved to 2.5 times higher than necessary, and we have created a new emergency stop and 10 mm steel turnbuckles that stabilize the wind turbine and reduce twisting,” adds Mathias Pender Nielsen and explains that the new security system means that the wind turbine can be dismantled in about a minute in case of an emergency.
The wind turbine is designed to deliver 100 Watts for the battery at a wind speed of 5-7 m/s. A 15 m/s wind speed is as fast as it can go. Therefore, the group has brought another wind turbine—one with a horizontal rotor—in order to determine which one is more efficient under the festival’s specific conditions.
In a test in Dream City on Monday, it was clear that the wind speed at the festival was too much for the rotor. Therefore, the group—with the current wind conditions at this year’s festival—will remove some of the blades to make the turbine slower.
The flexible design means that the wind turbine is easy to dimension in relation to conditions. The group envisages that it could easily provide electricity for e.g. a water filtration system at a refugee camp. But for the time being, they are aiming to develop a product that can be security-cleared for use in the larger camps at the festival, which require a lot of power.
“I stayed in a camp in Dream City at one time, where I was responsible for the system and the batteries, which were very large and weighed 50 kg each. We had to transport them 1.5 kilometres on a sack truck in order to charge them. It was an almost insurmountable task, which took about an hour. With our wind turbine it will be possible to make do with smaller batteries, and we also believe that you will be more inclined to take the wind turbine back home with you rather than an excessively heavy battery, which is unfortunately quite often left behind at the festival site,” says Jonathan Vestergaard Nielsen.
The students will therefore also study the festival guests’ reactions to the wind turbine and assess whether there is a market for it. The production price of this year’s prototype was around EUR 175 (DKK 1,300). On top of this comes, among other things, the prefabricated rotor.
The group expects a complete wind turbine to cost approximately EUR 530. This is a long way from the heavy truck batteries, which they estimate cost approximately EUR 67 from an auto salvage yard. On the other hand, the weight is considerably reduced, and the wind turbine is designed to last for 15 years of all-year operation.
DTU Wind Energy. Press release - Roskilde Music Festival: Mobile wind turbine version 2.0. URL: https://www.dtu.dk/english/news/Nyhed?id=F47884BD-255E-487C-AD6C-189920A203ED. [Date Accessed: 03/07/2019].
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