Lillgrund

Lillgrund Offshore Wind Farm Profile

Location: The Lillgrund offshore wind farm is situated in the Öresund region, approximately 7 km off the coast of Sweden and 7 km south of the Öresund Bridge, which connects Sweden and Denmark.

Ownership and Operation: The wind farm is owned and operated by Vattenfall Vindkraft AB. It is a Swedish pilot project supported by the Swedish Energy Agency.

Construction and Operational History: The bidding process for the project was completed in 2005, and the construction took place from 2006 to 2007. The wind farm has been operational since December 2007.

Wind Turbines and Capacity: The Lillgrund wind farm consists of 48 Siemens SWT-2.3-93 wind turbines, each with a rated capacity of 2.3 MW. The total installed capacity of the wind farm is 110 MW. Each turbine has a rotor diameter of 92.6 meters.

Energy Production: The wind farm generates approximately 300 GWh of electricity per year, which is enough to power around 60,000 households.

Site Conditions: The area where the wind farm is located has an average wind speed of about 8.5 m/s at hub height. The water depth in this region is relatively low, ranging from 4 to 8 meters, making it economically feasible for the construction of the wind farm.

Technical and Electrical Aspects: During the construction phase, an electrical system study was conducted by Siemens Wind Power, which revealed several issues, including insufficient insulation levels in the main transformer and the need for surge arresters in all turbines. Additionally, large transients were observed when the 130 kV main circuit breaker was switched on. These findings highlighted the importance of conducting thorough electrical system studies before construction begins.

Simulation and Research: The Lillgrund wind farm has been the subject of various studies and simulations aimed at improving the understanding and modeling of wind farm performance. For example, the HAWC2Farm simulation methodology has been used to model the wind farm's performance, including wake interactions and the effects of yaw control and turbine shutdown. This methodology combines state-of-the-art engineering models to simulate the complex dynamics within wind farms accurately.

In summary, the Lillgrund offshore wind farm is a significant installation in the Öresund region, contributing substantially to renewable energy production while serving as a valuable case study for advancing wind farm simulation and optimization techniques.