Why is wind a renewable energy resource?
For thousands of years, people around the world have used the force of the wind to lift, push, and pound. With the invention of devices that can turn motion into voltage, wind is a power source that will never run low no matter how often we use it.
The force of wind has been driving our technology since ancient times. Caught in a sail, it can drive transport over long distances. Connect the sail to a series of shafts and gears, wind can turn a millstone to grind grain into flour, or pump water.
Today, that same power can be used to turn turbines that push electricity through a conductor to power our world. Turbines turn huge magnets that generate a magnetic field, causing electrons to race through copper wires, generating electricity. This kind of electricity-generating mechanism is called a dynamo or generator.
As each pole of the magnet moves over the conductor, it pushes then pulls at electrons, creating an alternating current. Pretty much anything could be used to turn a generator. Like a flowing river. A dinosaur brought back from extinction. Your uncle Frank. Steam from a volcano. Steam from a tank heated by burning coal, oil, or gas. Or, of course, the wind.
Some of these are going to be more efficient power sources than others. Some will leave a mess that’s hard to clean up. Some won’t be replaced as quickly as we use them up, meaning they will run out eventually. We say these kinds of energy resources are non-renewable.
Others are replenished as quickly as they’re used or, as we say, are renewable. Take the wind, for example. Light energy from the Sun hits the planet’s surface, warming it up. This heat causes particles to move quicker, causing them to spread out and make the air less dense. Patches of warm, less-dense air rise, which leaves space for cooler air to rush in. The rising air loses its heat, causing it to sink again.
This circle of rotating air is called a convection current, but we feel it on the ground as wind. And of course, we can convert that wind into energy by using a wind turbine. Thanks to differences in sunshine and surface conditions, wind blows with more force, or more reliably, in some parts of the world than others, so some areas are better suited to wind farms, or creating wind power, than others.
Wind turbine technology is steadily getting better at converting breezes into electricity by finding tougher, lighter materials, for taller towers, and larger blades, to catch more wind. Different designs of wind turbine can also take advantage of different wind speeds and suit different purposes. Each design takes some energy out of the wind, and turns it into electricity for a home, or the power grid.
As long as the Sun shines on our planet the wind will blow, making it a renewable resource we can continue to rely upon to power society’s needs far into the future.