The effects from a wind farm on Gävle Energis electrical grid

The effects from a planned wind farm on the grid utility Gävle Energis electrical grid have been studied. The wind farm is planned to be built in the forest 15 km north of Gävle and will have 23 turbines with rated power from 2 to 2.5 MW, resulting in a total installed power between 46 MW and 57.5 MW. The grid connection will be made at 70 kV. The aim of the analysis was to determine what effects the wind farm would have on the power grid in the form of electrical disturbances (flicker etc.), need for new investment and raised operational cost. To allow the connection of the wind farm technical solutions (new lines, power stations and grid reinforcements) have been constructed. The effects and need for further investment if a larger wind farm is built have also been studied. Calculations of the electrical noise where made, using data for 5 different wind turbines, and compared to the maximum allowable levels. Connections using both overhead lines and cables where studied. The majority of costs used in the economical analysis where taken from EBR:s widely used cost catalogue. The analysis shows that 57.5 MW can be installed with all the turbine models. The need for new investment depends on the line used but is in the range of 38.300.000 SEK to 61.100.000 SEK. Up to 63 MW can be installed without any further investment and up to 98 MW if further investment is made