A pitch energy module comprising one or more ultracapacitors storing electrical energy for a wind turbine emergency pitch energy event. The pitch energy module replaces at least one battery within a battery housing of a wind turbine and interfaces with the existing battery wiring harness to communicate with a control system of the wind turbine. The pitch energy module is installed without further modification to the battery housing or the battery wiring harness.

A wind turbine blade including two electrically conductive spar caps, two lightning down conductor arrangements, and a further electrical conductor, wherein the spar caps and the lightning down conductor arrangements extend along a spanwise direction of the blade at least between a root-side end portion and a tip-side end portion of the blade, wherein each of the spar caps is electrically connected to only one of the lightning down conductor arrangements within a section of the blade between the root-side end portion and the tip-side end portion, wherein the further electrical conductor is electrically connected within the section to only one of the spar caps and/or to only one of the lightning down conductor arrangements at one or more connection positions is provided.

A method is for testing a functionality of a system of a wind turbine. The system includes an electro-mechanical actuator, an energy storage unit, and an energy dissipating element connectable to the energy storage unit for selectively transferring energy from the energy storage unit to the energy dissipating element. The method includes: providing first information representative of an operating mode of the system, and, if the operating mode is a test mode: causing a discharging of energy from the energy storage unit and a supply of at least a portion of the discharged energy to the energy dissipating element; receiving measurements being representative of a state of at least one of the energy storage unit and the energy dissipating element during the discharging and the supply; and determining a functionality of at least one of the energy storage unit and the energy dissipating element based on the measurements.

The present invention relates to a wind turbine park (100), comprising at least a first wind turbine (110) and a second wind turbine (120) for generating a power product, and a main line (101) connecting the first wind turbine (110) and the second wind turbine (120) for transporting the power product. The wind turbine park (100) further comprises an auxiliary power line (102) being connected to the first wind turbine (110) and the second wind turbine (120), wherein the auxiliary power line (102) is configured for transporting auxiliary power for a wind turbine maintenance or standby operation to at least one of the first wind turbine (110) and the second wind turbine (120). Furthermore, the wind turbine park (100) comprises an auxiliary power unit (103) for generating the auxiliary power, wherein the auxiliary power unit (103) is connected to the auxiliary power line (102).