Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetative cover. This wind flow, or motion energy, when "harvested" by modern wind turbines, can be used to generate electricity.
The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity to power homes, businesses, schools, and the like.
Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current. Simply stated, a wind turbine is the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity
Another example if wind energy are silent small wind turbines scaled to the right size for residential and urban areas have so far lived in the shadows of their larger wind-farm-sized counterparts. The power output has been too low for a reasonable return on investment through energy savings and the noise they produce is louder than most homeowners can deal with.
A Dutch renewable energy start-up called The Archimedes is working to solve both of those problems in a new class of small-scale wind turbine — one that is almost silent and is far more efficient at converting wind into energy. The company states that the Liam F1 turbine could generate 1,500 kWh of energy per year at wind speeds of 5m/s, enough to cover half of an average household's energy use.
When used in combination with rooftop solar panels, a house could run off grid. "When there is wind you use the energy produced by the wind turbine; when the sun is shining you use the solar cells to produce the energy," The Archimedes CEO Richard Ruijtenbeek said.
The Liam's blades are shaped like a Nautilus shell. The design allows it to point into the wind to capture the most amount of energy, while also producing very little sound. The inventor of the turbine Marinus Mieremet says that the power output is 80 percent of the theoretical maximum energy that could be harnessed from the wind. – read full article here from treehugger.com –