Wind energy (or wind power) is a clean, cost-effective, renewable source of energy created through the use of large turbines. Wind energy refers to the process by which wind turbines convert the movement of wind into electricity. 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 energy is harnessed through the use of wind turbines. Wind turbines have three aerodynamically designed blades which spin on a shaft which connects to a generator that produces electricity.

Wind passes over the blades, creating lift (just like an aircraft wing) which causes the rotor to turn. Stronger winds will produce more energy. Wind turbines can operate across a wide range of wind speeds - generally from 10 up to 90 km/h. Wind turbines are mounted on a tower to capture the most energy. At 30 metres or more above ground, they can take advantage of faster and less turbulent wind.

The majority of current turbine models make best use of the constant variations in the wind by changing the angle of the blades through "pitch control", by turning or "yawing" the entire rotor as wind direction shifts and by operating at variable speed. Operation at variable speed enables the turbine to adapt to varying wind speeds.

Sophisticated control systems enable fine tuning of the turbine's performance and electricity output. Modern wind technology is able to operate effectively at a wide range of sites – with low and high wind speeds, in the desert and in freezing arctic climates.

In a wind farm, individual turbines are interconnected with a power collection system and a communications network.
The power is then transferred to the electricity grid.

Wind—a new source of energy for NL

Wind is a valuable energy source and Hydro has developed a strategy to leverage this source of clean, renewable energy. In 2007, Hydro secured power purchase agreements for 54 MW of wind energy on the island – one 27 MW wind project in St. Lawrence and a 27 MW project in Fermeuse. On average, when compared to the cost of burning oil at Hydro's Holyrood Generation Station, these two wind projects will save consumers up to eight million dollars annually over the 20-year life of the contracts.

St. Lawrence Wind Farm

In early 2007, Hydro signed a 20-year power purchase agreement with NeWind Group Inc., a subsidiary of ENEL North America Inc. It is located about one kilometre northwest of the community of St. Lawrence on the Burin Peninsula. The wind farm has nine Vestas V90, 3 MW turbines (27MW) and began producing wind power to the electricity grid in October 2008.

Fermeuse Wind Project

In 2008, Hydro signed a 20-year power purchase agreement for a 27 MW wind farm located in the community of Fermeuse on the Southern Shore, Avalon Peninsula. The project consists of nine, Vestas V90, 3 MW turbines. The project began supplying wind energy in April 2009.

Wind turbines and the environment

Wind generation is an environmentally-friendly, pollution-free and endless source of energy. It is clean and limitless and leaves a small environmental footprint on the province. On the island of Newfoundland, wind generation helps reduce fossil-fired generation at Hydro's thermal generating station in Holyrood.

In 2010, Hydro purchased 183,252 megawatt hours of clean energy from the island's two wind projects. That's enough green energy to power over 12,300 homes – which is equivalent to burning 290,000 barrels of oil at the Holyrood plant, and is a reduction of more than 143,000 tonnes of greenhouse gas emissions.

Hydro's parent company, Nalcor Energy, has also installed 300 kilowatts of wind power as part of its Wind-Hydrogen-Diesel energy project in the community of Ramea, on the southwest coast of Newfoundland.

There are many benefits to wind energy and has a place in Hydro's electricity generation. Wind energy is fueled by the wind, so it's a clean fuel source. Wind energy does not generate air pollution or produce atmospheric emission that causes acid rain or GHGs.

However, there are technical and operational considerations limit the amount of wind generation that can operated on the system. Electricity generated from wind power can be highly variable at several different timescales – from hour to hour, daily, and seasonally. Because instantaneous electrical generation and consumption must remain in balance to maintain stability and ensure the electricity is available when the customer needs it, this variability can present substantial challenges to incorporating large amounts of wind power.