Wind energy is not merely related to solar energy; it is a form of solar energy. The sun lights the entire planet, but different areas of the Earth absorb different amounts of its energy. Deserts and oceans, for example, reflect more rays while forests and other land areas absorb them. Absorbed sunlight becomes heat, which warms the air above the Earth’s surface. The warm air expands and rises, and cooler, denser air flows underneath to take its place. We call this air movement wind.
Humans learned to harness the power of the wind before they even invented writing. Sails are the most prominent example; as early as 5000 BC, Egyptians traveled the Nile River on wind-powered boats. 9th century Persians developed a horizontal windmill to crush grain and pump water. The invention spread across central and eastern Asia, and later northwestern Europe. Today, wind power accounts for around 11% of all electricity in the European Union.
Like solar energy, wind energy is a clean and renewable resource that comes from the sun. But due to the varied topography of the Earth, wind is unevenly distributed. Coastal areas are typically more windy because the warm air above the land interacts with cooler air blowing in from the sea (or other body of water).
Earth’s surface friction also slows the wind. Being farther from the surface, high altitudes like mountaintops are more windy. Plains such as the American midwest are major wind zones because they lack the natural friction provided by trees and hilly terrain.
Though wind and solar energies share a source, wind power is less consistent. It requires more strategy to capture. One must study the geography of an area and measure the local wind speeds to ensure that the wind energy converting system will be effective.
Wind turbines are easily more efficient than solar panels. While solar panels use photovoltaic cells to stimulate electron movement, turbines simply channel air’s kinetic energy (wind) into mechanical energy (spinning blades) that powers a generator. But there are obstacles to building successful turbines. They must stand at least 30 feet taller than the tallest structure in the area, ideally in a treeless, unpopulated place. Wind farms with multiple turbines take up a lot of space.
Solar and wind energy are related because they both come from the Earth’s most important resource–the sun. Over the centuries, people have designed various systems for channeling this incredible, boundless energy into something that can sustain our society without hurting the earth.