china has the most wind turbines in the world.
china has the most wind turbines in the world.
who has the most wind turbines in the world?
china
nearly all modern wind turbines uses rotors with three blades, but some use only two blades. this was the type used at kaiser-wilhelm-koog, germany, where a large experimental two-bladed unit—the growian, or "große windkraftanlage" (big wind turbine)—operated from 1983 to 1987. other prototypes and wind turbine types were manufactured by nedwind. the eemmeerdijk wind park in zeewolde, netherlands uses only two-bladed turbines. wind turbines with two blades are manufactured by nordic windpower, such as model # n 1000, and by gc china turbine corp. the nasa wind turbines (1975-1996) each had 2-blade rotors, producing the same energy at lower cost than three-blade rotor designs.
unconventional wind turbines
the use of undersized wind turbines in energy production in sustainable structures requires the consideration of many factors. in considering costs, small wind systems are generally more expensive than larger wind turbines relative to the amount of energy they produce. for small wind turbines, maintenance costs can be a deciding factor at sites with marginal wind-harnessing capabilities. at low-wind sites, maintenance can consume much of a small wind turbine's revenue. wind turbines begin operating when winds reach 8 mph, achieve energy production capacity at speeds of 32-37 mph, and shut off to avoid damage at speeds exceeding 55 mph. the energy potential of a wind turbine is proportional to the square of the length of its blades and to the cube of the speed at which its blades spin. though wind turbines are available that can supplement power for a single building, because of these factors, the efficiency of the wind turbine depends much upon the wind conditions at the building site. for these reasons, for wind turbines to be at all efficient, they must be installed at locations that are known to receive a constant amount of wind (with average wind speeds of more than 15 mph), rather than locations that receive wind sporadically. a small wind turbine can be installed on a roof. installation issues then include the strength of the roof, vibration, and the turbulence caused by the roof ledge. small-scale rooftop wind turbines have been known to be able to generate power from 10% to up to 25% of the electricity required of a regular domestic household dwelling. turbines for residential scale use are usually between 7 feet (2 m) to 25 feet (8 m) in diameter and produce electricity at a rate of 900 watts to 10,000 watts at their tested wind speed. building integrated wind turbine performance can be enhanced with the addition of an aerofoil wing on top of a roof mounted turbine.
sustainable architecture