Harnessing wind is not a new concept, really; it has been around for thousands of years. Windmills as a practical device, harnessing wind energy to mill grain, have existed since between the 7th and 9th century. A Greek engineer by the name of Heron of Alexandria built a wind powered organ in the 1st century. This is the first known instance of using a windmill to power a machine. But even before then, wind energy was harnessed to sail ships as far back as 5000 BC. Today, wind turbines are a common sight, harnessing wind energy to produce cheap electricity.
Wind turbines are very large. Some of them are about 328 feet tall, which is larger than the Statue of Liberty in New York City. They are also comprised of over 8,000 different components, making them very technologically complex. Most of these components are manufactured in the US among 500 manufacturing facilities employing 50,000 people. The main components we see are the blades, which can reach a staggering 260 feet long, the rotor, which is the hub the blades are connected to, the nacelle, which contains all of the electrical and mechanical components, and the tower the nacelle sits atop. Inside the nacelle, there is a low speed shaft, a gear box, a high speed shaft, and a generator for making electricity. There are also various computer systems to tell the wind turbine how to align itself relative to the wind to maximize energy harnessing and minimizing risk of damage in high winds.
Higher speed winds allow the turbine to generate more electricity. The low speed shaft only spins up to about 30-60 RPMs, but the turbine requires about 1000-1800 RPMs to generate electricity. A gearbox changes the RPMs from the low speed shaft to the high speed shaft, and it is the most expensive parts of the turbine. Higher winds mean the gear spin faster, but winds over 55 mph can damage the blades. Higher speed winds are located higher above the ground, which is why wind turbines have grown 103% in size since 1998.
Wind energy accounts for 33% of new energy production in the United States in the past seven years. If we were to line all of the coastlines of the US with wind turbines, we would have four times the amount of electricity needed for the entire country. Unfortunately, it’s not really practical at this point to do that, but it provides insight into lining coastal waters near highly populated coastal cities. However, the total capacity of wind turbines in the US is over 61 gigawatts, which could power more than 16 million homes, more than all the homes in California.
Wind energy is cheap and renewable, costing as little as 2.5 cents per kilowatt hour for energy companies to purchase the electricity. Tax credits for using renewable energy are part of the reason for these low prices, and the more people choose to use renewable energy, the lower the price will get. Remember that you have the power to choose not only your energy provider but also your energy plan. Check with your REP to see if they have green plans available that take advantage of wind energy.