A crucial factor affecting the energy yield of a wind turbine, besides air density and wind speed, is the rotor swept area over which the wind flows. This swept area, in turn, is determined by the length of the rotor blades. The industry trend is clearly heading in the direction of longer and longer rotor blades. The Siemens rotor consisting of three 75-meter rotor blades has a diameter of 154 meters and covers a surface area of approximately 18,600 square meters, equal to about two and a half soccer fields. The Siemens 6 megawatt wind turbine will generate about 65% more energy using the 75-meter rotor blade compared with the Siemens 3.6 Megawatt bestseller using the earlier blade with a length of 58 meter.
Dong Energy ordered a total of 300 6-megawatt wind turbines featuring the record rotor measuring 154 meters in length. These wind turbines are to be installed in wind power plants off the British coast between 2014 and 2017.
Joyce Solar Actuators are designed to precisely position smaller solar tracking equipment. Their robust and efficient DC motor (24V or 36V) keeps power consumption to a minimum. Travel speeds remain nearly constant regardless of the load. Ideal for rugged environments common to the solar industry, these cost-effective SA actuators have an IP65 protection rating. Self-locking features in the mechanism ensure that the solar actuator will hold position throughout the daily tracking cycle. Specifications: • Double clevis mounting for easy installation • Clutch for overload protection • Adjustable limit switches for flexible travel settings • Reed sensor digital feedback for accurate positioning • Duty cycle is 25% (4 min. running, 12 min. rest) • Lubricated for life