Cold-climate projects comprise a staggering 25% of the world wind market, according to consultancy BTM in its latest World Market Update. These locations tend to have high wind resource, especially during winter. Conversely, ice on the turbine blades can affect power production by up to 20%.
Yet, surprisingly, this is the first de-icing solution the company has designed. Vestas chief technology officer Anders Vedel said this new de-icing solution is in response to customer demand, a signal that developers are now being more creative in their search for new wind project sites.
The Vestas de-icing system (VDS) consists of a heating unit in the hub to distribute hot air throughout the blades. The outer third of the blade and two thirds of the leading edge are fully de-iced. The company has received its first order for four V112 3.3MW turbines to go to a project in Austria. The first prototype is currently being installed in Sweden.
Trigger
The VDS is integrated into the wind turbine's Scada system, explains Vedel. An algorithm is set to trigger the de-icing when the potential power loss caused by ice becomes greater than the potential power loss while the turbine is switched off for de-icing. In all the de-icing process across all three blades takes two hours. Only the blades need to be de-iced as the wind measurement systems are already designed to avoid ice accumulation.
"The VDS is an active de-icing solution consisting of an ice detection system and a hot air flow unit within the blades," said Vedel. "The hot air flow targets the blade's most critical parts to efficiently melt ice build-up, with no negative impact on the noise level or overall performance of the turbine," he added.
"VDS will provide significant value to customers who want to harness the potential of wind power in colder climates with icing risk such as North America as well as the northern and central regions in Europe, which were previously not economically feasible due to the risk of ice affecting power production." The system adds minimum weight while the heating unit uses 150kW, he said.
Testing
During the development process, the company spent last winter testing a prototype turbine that used the system in Canada. It had looked at other solutions to hot air, such as coating the blade and integrating heating elements within the blade. The former was found to not be effective enough, and the latter was dismissed as it could pose a danger to the turbine.
The VDS system will be available for the V112 3.3MW and V117 3.3MW turbines.
