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.
Sierra was the first to introduce a combination volumetric vortex and multivariable mass flow meter in 1997. Today, Sierra's completely redesigned InnovaMass® iSeries™ 240i/241i builds on two decades of success measuring five process variables for gas, liquid and steam with one connection. Now, with the latest hyper-fast microprocessors, robust software applications, field diagnostic and adjustment capability, and a new state-of-the-art flow calibration facility, Sierra's vortex iSeries delivers precision, performance, and application flexibility never before possible.