If you've ever visited California and taken a drive east down the 10 freeway from Los Angeles to Palm Springs, you'll pass a series of windmills.
This is the Alta Wind Energy Center in the Tehachipi Pass, one of the windiest spots in California. In the wind power industry, the center is currently the largest onshore wind farm in the United States, boasting a total power capacity of roughly 1500 Megawatts.
How many wind farms are there?
According to the AWEA, the U.S. has "approximately 1,000 utility scale wind projects, which represent 74,512 megawatts (MW) and over 48,800 wind turbines installed across 40 U.S. states plus Puerto Rico and Guam."
In other words, the United States has enough wind energy capacity across these projects to generate power for 15 million homes.
What types of wind farms are there?
- Onshore Wind Farms
Onshore wind farms are groupings of wind turbines clustered into a windy area on land.
Each turbine sits atop a large steel tube (called a "tower") that gets it exposure to wind blowing at higher speeds. A series of blades spin the axis of the turbine when the wind blows over them.
- Offshore Wind Farms
Offshore wind farms are collections of wind turbines located in water.
They are often built in the ocean but also on lakes and fjords when wind speeds are strong enough. Offshore wind farms generally experience stronger wind speeds due to their location. They are capable of harnessing a colossal amount of power.
However, given the logistics of building them in the middle of large bodies of water, they tend to be more expensive than onshore wind farms. As of December 2016, the first offshore wind farm in the United States was completed off the coast of Rhode Island.
Another one off the coast of New Jersey is still under construction. As the technology gets cheaper, the more it just makes sense to harness the tremendous power potential of offshore wind farms.
Aren’t wind turbines really noisy?
This is a common fear when wind farm projects are suggested near residential regions.
The fact is, wind turbines actually are very quiet considering how large they are. Typically, wind turbines are built roughly 300 meters from any residential housing. At that distance, the turbine will generate a sound pressure level of 43 decibels.
To put that into perspective, a mid-size window AC unit generates sound pressure levels of 50 decibels. If you were to walk right up to the wind turbine, it would sound as loud as a typical gas-powered lawn mower (105 decibels). Offshore wind farms completely absolve this issue though, as they are put out in the water far away from any residential housing.
What happens to the local environment where a wind farm is built?
While the power that is generated by a wind farm is 100% clean, there are some ecological concerns surrounding wind farms.
Most have to do with the deaths of birds and bats that run into the rotors, but as long as the build site is properly vetted, the impact on the local environment should be very low.
Did you know that you can support wind farms and the wind power industry simply by paying your bill? Find out how.