A transportation vehicle may be equipped with electrical energy harvesting systems to harvest electrical energy for use. By way of example, in the transportation vehicle, a Venturi system may be used to receive an air flow and the speed of the air flow increase in a constricted area of the Venturi system, the air flow containing a large amount of kinetic energy. A plurality of electrical energy harvesting systems is disposed in the Venturi system and is configured to convert the kinetic energy contained in the accelerated air flow into electrical energy that can be used to power on-board electronics as well as one or more on-board batteries in the transportation vehicle, as the transportation vehicle is in motion.

Provided is an eco-friendly wind power generation apparatus that can perform power generation using wind by providing the blades of a wind power generator on a jib of a tower crane, and can perform wind power generation at the optimum altitude and in the optimum direction by automatically or manually performing the lifting or lowering and swing operation of a jib even when wind speed is insufficient because wind is not blowing, or perform wind power generation using artificial wind power generated by the operation of the jib, thereby generating a lot of electricity in necessary places and supply the electricity to all industrial sectors regardless of location and environment.

Provided is an eco-friendly wind power generation apparatus that can perform power generation using wind by providing the blades of a wind power generator on a jib of a tower crane, and can perform wind power generation at the optimum altitude and in the optimum direction by automatically or manually performing the lifting or lowering and swing operation of a jib even when wind speed is insufficient because wind is not blowing, or perform wind power generation using artificial wind power generated by the operation of the jib, thereby generating a lot of electricity in necessary places and supply the electricity to all industrial sectors regardless of location and environment.

The present invention relates to a multirotor wind turbine comprising at least two rotor nacelle assemblies mounted to a support arrangement via respective yawing systems, and a toe angle control system for controlling the toe angles of the rotor nacelle assemblies with respect to the support arrangement; wherein the toe angle control system is configured to operate in a first mode in which the rotor nacelle assemblies are held at positive toe angles while the wind turbine is generating power in a main production mode; wherein the toe angle control system is further configured to monitor the operating mode of the wind turbine, and to switch to a second mode in which the yawing systems of the rotor nacelle assemblies are operated to reduce the toe angles of the rotor nacelle assemblies if an operating mode-based trigger condition has been met.

The present invention relates to a multirotor wind turbine comprising at least two rotor nacelle assemblies mounted to a support arrangement via respective yawing systems, and a toe angle control system for controlling the toe angles of the rotor nacelle assemblies with respect to the support arrangement; wherein the toe angle control system is configured to operate in a first mode in which the rotor nacelle assemblies are held at positive toe angles while the wind turbine is generating power in a main production mode; wherein the toe angle control system is further configured to monitor the operating mode of the wind turbine, and to switch to a second mode in which the yawing systems of the rotor nacelle assemblies are operated to reduce the toe angles of the rotor nacelle assemblies if an operating mode-based trigger condition has been met.

A multirotor wind turbine (1) comprising a yaw arrangement (6) and a tower (2) is disclosed. A load carrying structure comprises first and second arms (3) extending from the yaw arrangement (6) and carrying energy generating units (4). the yaw arrange-ment (6) comprises an outer wall part (7) arranged coaxially with the tower (2) and forming a closed ring extending circumferentially about an outer surface of the tower (2), thereby forming a space (8) between the tower (2) and the outer wall part (7). The outer wall part (7) and the outer surface of the tower (2) are rotatable relative to each other.

A multirotor wind turbine (1) comprising a yaw arrangement (6) and a tower (2) is disclosed. A load carrying structure comprises first and second arms (3) extending from the yaw arrangement (6) and carrying energy generating units (4). the yaw arrange-ment (6) comprises an outer wall part (7) arranged coaxially with the tower (2) and forming a closed ring extending circumferentially about an outer surface of the tower (2), thereby forming a space (8) between the tower (2) and the outer wall part (7). The outer wall part (7) and the outer surface of the tower (2) are rotatable relative to each other.

A first aspect of the invention provides a method of monitoring the condition of a yaw system of a wind turbine, the wind turbine comprising a rotor, the yaw system arranged to control a yaw rotation of the rotor, the method comprising: providing design data 5 representing an expected relationship between yaw moment and yaw rotation speed; measuring a pair of parameters, the pair of parameters comprising a yaw moment parameter indicative of a yaw moment applied to the yaw system, and a yaw rotation speed parameter indicative of a yaw rotation speed caused by the yaw moment; using the design data to evaluate whether the pair of parameters deviates from the expected 10 relationship; and determining a condition of the yaw system on the basis of the evaluation.

The invention relates to a method for monitoring performance of a multi-rotor wind turbine. According to the method parameter for each of the wind turbine modules of the multi-rotor wind turbine is obtained. The parameters of each of the wind turbine modules are compared, e.g. by means of a comparison parameter determined from the individual parameters. Dependent on the result of the comparison, a performance action is initiated, e.g. for the purpose of further characterization or verification of a deviating parameter determined via the comparison.

The invention relates to a method for monitoring performance of a multi-rotor wind turbine. According to the method parameter for each of the wind turbine modules of the multi-rotor wind turbine is obtained. The parameters of each of the wind turbine modules are compared, e.g. by means of a comparison parameter determined from the individual parameters. Dependent on the result of the comparison, a performance action is initiated, e.g. for the purpose of further characterization or verification of a deviating parameter determined via the comparison.