A method for operating a wind farm connected to a power grid that demands a reactive power requirement that varies with active power includes monitoring a wind speed at each of the plurality of wind turbines in the wind farm. When the wind speed is within a cut-in wind speed range, the method includes determining a reactive power margin of the wind farm based on the reactive power requirement at an active power output corresponding to the wind speed and a reactive power availability of each of the plurality of wind turbines at the wind speed. The method also includes determining a lowest possible cut-in rotor speed for each of the plurality of wind turbines that satisfies the reactive power margin. Further, the method includes commanding each of the plurality of wind turbines to cut-in and begin to produce power at the lowest possible cut-in rotor speed that satisfies the reactive power margin.

A method for operating a wind farm connected to a power grid that demands a reactive power requirement that varies with active power includes monitoring a wind speed at each of the plurality of wind turbines in the wind farm. When the wind speed is within a cut-in wind speed range, the method includes determining a reactive power margin of the wind farm based on the reactive power requirement at an active power output corresponding to the wind speed and a reactive power availability of each of the plurality of wind turbines at the wind speed. The method also includes determining a lowest possible cut-in rotor speed for each of the plurality of wind turbines that satisfies the reactive power margin. Further, the method includes commanding each of the plurality of wind turbines to cut-in and begin to produce power at the lowest possible cut-in rotor speed that satisfies the reactive power margin.

A floating power generation station comprises a floating hull with a shelter structure containing photovoltaic solar panels are arranged on a chain of floats, each hinged one to the next. The system can be deployed onto a large flat area, e.g., surface of inlet or bay, where the solar panel chain(s) can be extended out. The power generation station may include air displacement tubes that have a lower end immersed in water, and which feed into a plenum where check valves direct air unidirectionally to an air turbine that powers an electric generator. Air turbines or wind turbines on the barge can be raised or tipped up for collection of wind energy. The captured energy is stored on a bank of on-board storage batteries. Energy can be collected and stored, and the barge can be brought to shore when and where needed. This arrangement can be configured for ground-based deployment. The power generation station can be configured for use on dry land.

A floating power generation station comprises a floating hull with a shelter structure containing photovoltaic solar panels are arranged on a chain of floats, each hinged one to the next. The system can be deployed onto a large flat area, e.g., surface of inlet or bay, where the solar panel chain(s) can be extended out. The power generation station may include air displacement tubes that have a lower end immersed in water, and which feed into a plenum where check valves direct air unidirectionally to an air turbine that powers an electric generator. Air turbines or wind turbines on the barge can be raised or tipped up for collection of wind energy. The captured energy is stored on a bank of on-board storage batteries. Energy can be collected and stored, and the barge can be brought to shore when and where needed. This arrangement can be configured for ground-based deployment. The power generation station can be configured for use on dry land.

The objective is to realize a rotation storage device with a lightweight and straightforward configuration that can release the energy of various urging means, typically a flat coil spring, over a more extended period and increase the urging force. The rotation storage device includes a plurality of single unit rotation storage devices that comprise of an urging means for urging of the rotational force and a one-way bearing with one end of the urging means fixed to one of its outer ring or inner ring, wherein a plurality of single unit rotation storage devices are characterized in that the outer ring and inner ring of the one-way bearings are connected, the other end of the urging means connected to one end of the urging means of the adjacent unit rotation storage device, and the rotation force is output between the outer ring and inner ring of the one-way bearing.

A device for a traction kite for generating electricity by means of wind force, wherein exact horizontal positioning of a traction kite or of a group of interconnected traction kites or rotating flyer wheels is made possible in that obliquely braced additional traction ropes 4 at the edges of this traction kite group permit a fixed position of the traction kite, similar to when bracing domestic tents.

A device for a traction kite for generating electricity by means of wind force, wherein exact horizontal positioning of a traction kite or of a group of interconnected traction kites or rotating flyer wheels is made possible in that obliquely braced additional traction ropes 4 at the edges of this traction kite group permit a fixed position of the traction kite, similar to when bracing domestic tents.

A system for sustainable generation of energy, comprising at least one device for converting natural power into useful energy, and at least one internal combustion engine or heat engine. The internal combustion engine or heat engine may be connected to a gas cleaning device for fuel or heat supply. A method for sustainable generation of energy, comprising the steps of generating a first amount of useful energy by converting natural power; and generating a second amount of energy by operating at least one internal combustion engine or heat engine, wherein the internal combustion engine or heat engine is driven by fuel or heat derived from cleaning a waste gas.

A system for sustainable generation of energy, comprising at least one device for converting natural power into useful energy, and at least one internal combustion engine or heat engine. The internal combustion engine or heat engine may be connected to a gas cleaning device for fuel or heat supply. A method for sustainable generation of energy, comprising the steps of generating a first amount of useful energy by converting natural power; and generating a second amount of energy by operating at least one internal combustion engine or heat engine, wherein the internal combustion engine or heat engine is driven by fuel or heat derived from cleaning a waste gas.

The present invention relates to a floating wind energy harvesting apparatus for offshore installation, the wind energy harvesting apparatus comprising: an elongated wind turbine body extending along a longitudinal wind turbine body axis, the wind turbine body comprising a lower body portion to be below a water surface when the wind energy harvesting apparatus is in operation and an upper body portion to be above the water surface when the wind energy harvesting apparatus is in operation; wind turbine blades attached to the upper body portion for converting wind energy to rotation of the wind turbine body around the longitudinal wind turbine body axis; an energy converter attached to the wind turbine body for converting the rotation of the wind turbine body in relation to a non-rotatable part to electrical energy; and anchorage means connecting the non-rotatable part to at least one anchor point via at least one float body.