Energy From Wind

by Alan S. Cajes

Note: This article was published by the Philippine Business in Environment in 2007.

Wind or moving air occurs when air in some parts of the planet heats up, expands and rises thereby allowing the heavier and cooler air to rush in to take its place. Wind, therefore, is a renewable energy source. As long as the sun shines, there will always be wind.

We can trace back the practice of using wind to produce energy to the ancient Egyptians. They used wind to sail ships on the Nile River over 5,000 years ago. Later, people built windmills to grind grains. The people of Persia are the first users of windmills, which look like large paddle wheels. Many years later, the people of Holland improve the basic design of the windmill by giving it propeller-type blades.

At present, people from various countries use windmills to generate electricity. Today’s wind machines collect the wind’s kinetic energy with the use of airfoil-shaped blades. The wind flows over the blades and cause them to turn. The spinning blades drive the shaft connected to them. The shaft then turns an electric generator that converts mechanical energy into electricity.

The two types of wind machines or turbines that are used today based on the direction of the rotating shaft (axis) are the horizontal-axis and the vertical-axis wind machines. There is a wide degree of variation in the size of the wind machines. A small turbine that can power a single house may have a capacity of less than 100 kilowatts. Some large turbines may have a capacity of five megawatts. To increase the capacity, larger turbines are often grouped together into wind farms, which provide power to the electrical grid. The world's largest wind farm, the Horse Hollow Wind Energy Center in Texas, has 421 wind turbines that generate enough electricity to power 230,000 homes per year. To operate a wind machine, careful planning must be done to determine the location of the machine. This involves determining how fast and how much the wind blows.

In the Philippines, the wind resource depends on latitude, elevation and proximity to the coastline. Based on studies, the best wind resources are found in six regions: (1) the Batanes and Babuyan islands north of Luzon; (2) the northwest tip of Luzon (Ilocos Norte); (3) the higher interior terrain of Luzon, Mindoro, Samar, Leyte, Panay, Negros, Cebu, Palawan, eastern Mindanao, and adjacent islands; (4) well-exposed east-facing coastal locations fromnorthern Luzon southward to Samar; (5) the wind corridors between Luzon and Mindoro(including Lubang Island); and (6) between Mindoro and Panay (including the Semirara Islands and extending to the Cuyo Islands). The potential installed capacity of these regions is more than 70,000 megawatts.

In Southeast Asia, the Northwind Bangui Bay Project in Ilocos Norte is the first wind power project. It is also the first carbon finance project in the Philippines. The project was inaugurated in June 2005. Its power generation capacity is 25 megawatts. In the world, the top five countries in terms of wind power capacity are Germany, Spain, United States, India and Denmark. Most of the wind power plants are located in Europe where government programs have helped support wind power development.

Wind energy is a viable and economical alternative to conventional power plants. Wind is a clean fuel. A wind farm does not produce air or water pollution. It does not burn fuel. Wind machines, however, have negative effect on wild bird populations and visual impact on the landscape.

References: Energy Information Administration, Renewable Energy Trends 2005, September 2004; The National Energy Education Development Project, Intermediate Energy Infobook, 2005; The American Wind Association, Wind Web Tutorial (http://www.awea.org/faq/index.html), 2007. The Global Wind Energy Council (http://www.gwec.net/), April 2007; FPL Energy (http://www.fplenergy.com/news/contents/090706.shtml), September 2006; U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (http://www1.eere.energy.gov/windandhydro/wind_how.html#sizes), May 2007.