Renewable Energy Sources: Wind Energy

In India, the wind power potential has been estimated at 45000MW. Experts consider that the technological advances in recent years in the field and the availability of sophisticated equipments would facilitate the country in achieving the target in future years. The wind power programme in the country was initiated way back in 1983/84, but actual development took place during the early nineties, when the Ministry adopted a market-oriented strategy to attract private investment in commercial projects. Today, power generation from wind has emerged as a successful programme, making a meaningful contribution to bridging the gap between the supply and demand for power. The present installed capacity of 1 080MW of wind power represents a little more than 1% of the total installed capacity in the country. As such, 860MW of wind power capacity was added during the Eighth Plan period as against the initial target of 100MW and the revised target of 500MW. More than 5 billion units of electricity have been generated and fed to the utility by wind power projects. Potential windy locations have been identified in the flat coastal terrain of southern Tamil Nadu, Kerala, Gujarat, Lakshadweep, Andaman & Nicobar Islands, Orissa and Maharashtra. Favourable sites have also been identified in some inland areas of Karnataka, Andhra Pradesh, Madhya Pradesh, West Bengal, Uttar Pradesh and Rajasthan. Locations having an annual mean wind power density greater than 150 watts per sq metre at 30 metre height will be considered suitable for wind power projects. There are 177 locations identified so far with an aggregate potential capacity of about 5500 MW in 13 states.

The Scheme
Wind turbines convert the wind’s kinetic energy 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
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.

Wind Turbine Types
Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water, and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor. Most large modern wind turbines are horizontal-axis turbines.
Turbine Components
Horizontal turbine components include:
• a blade or rotor, which converts the energy in the wind to rotational shaft energy;
• a drive train, usually including a gearbox and a generator;
• a tower that supports the rotor and drive train; and
• other equipment, including controls, electrical cables, ground support equipment, and interconnection equipment.
Some wind machines have fail-safe shutdown systems so that if part of the machine fails, the shutdown systems turn the blades out of the wind or put on brakes.