The beginner's guide to wind farms

Wind is is just one way that renewable energy is being harassed to generate power around the world. These are some facts about wind power that may surprise you.

• A typical wind-electric system includes an AC generator. The current is converted from AC to DC inside the generator and is then carried by power lines from the generator to a control panel in a shed.
• Electricity generated from the turbine may be stored in batteries or reconverted to AC by an inverter for immediate household use.
• In most systems, the inverter is part of a regulatory control panel that protects batteries from overcharging.
• The inverter also automatically switches over to a liquid-fuel powered generator. This occurs when the batteries are exhausted, usually after too many wind-less days.
• There should be enough batteries to provide three or four days' storage for windless periods.

• Since the 1970s, there has been spectacular growth in the commercial wind-generation industry.
• In California, wind energy is expected to provide 10 percent of the state's electricity needs sometime this century.
• There are about 20,000 grid-connected wind generators throughout the world, which provide enough electricity for some 500,000 households.
• Australia's only commercial wind farm has nine wind turbines that generate electricity for the local grid. The farm's propellers account for approximately 12 percent of the district's electricity.
• In Canada, Quebec and Ontario are leading the way for wind power, with Alberta not far behind.

Today's wind turbines harness the wind so efficiently that, in the right location, one large unit can generate enough electricity to power an average­ home.