Wind 101

Welcome to the next phase of our renewable energy deep dive!

For the next few issues of ClimateRoots we will be getting into all things wind energy, starting with the basics; how wind turbines actually work. Wind power has been used by humans for centuries, from guiding boats at sea, to windmills that help break down grain, to becoming a primary source of renewable energy. Recent breakthroughs in wind technology have allowed for wind energy to be “increased from about 6 billion kilowatt-hours (kWh) in 2000 to about 338 billion kWh in 2020.” That’s over a 50x increase in production in 20 years! Wind is currently an extremely fast growing section of our energy mix and now produces about 8.4% of utility scale electricity (Electricity Generation from Wind - U.S. Energy Information Administration (EIA))

The basic idea behind wind energy is to harness the kinetic energy of wind currents and convert them into electricity using wind turbines. There are two main types of wind turbines in the United States. The one most of us are familiar with (often seeing them in large fields along highways) is the horizontal axis turbines. These turbines have three blades that directly face the wind. The other type of turbine is a vertical axis turbine, which have omnidirectional blades and do not need to face directly into the wind (“How Do Wind Turbines Work?”). We will be focusing on horizontal axis turbines since they are the most commonly used types of turbines.

A horizontal axis turbine works as such:

1. An anemometer measuring wind speed and direction sits on top of the nacelle (the box on top of the turbine) and ensures that the 3 rotating blades will face into the wind by controlling which direction the nacelle spins to face the blades (How Wind Turbines Generate Electricity | FWEE)

2. As wind pushes air through the blades, the shape of each blade causes a difference in air pressure to develop on either side of the blade. This air pressure difference between the two sides of the blade creates a “lift and drag” effect, and causes the blades to rotate (“How a Wind Turbine Works - Text Version”).

3. The blades then spin the rotor inside the nacelle. If you remember our education piece on how electricity is generated with steam turbines, the rest of this might sound a bit familiar (“How a Wind Turbine Works - Text Version”).

4. For those of you who have watched a wind turbine’s blades spin, you might be wondering how something rotating so slowly can generate all that power. The short answer is it can’t. After the rotor is spinning, a series of gears inside the gearbox step up the rotation speed by 100x, from about 18 rpm to 1,800 rpm (“How a Wind Turbine Works”)

5. The, now quick, rotation of the generator inside the nacelle moves a magnetic rotor surrounded by copper wire creating a flow of electrons that gets sent to the energy grid fully converted to electrical energy! (How Wind Turbines Generate Electricity | FWEE).

There are a few key components to deciding where wind turbines or wind farms will be located. Smaller turbines are located where the average annual wind speed is 9 miles per hour (mph) and 13 mph for large scale turbines (Where Wind Power Is Harnessed - U.S. Energy Information Administration (EIA)). Favorable topography includes the top of rounded hills, open plains or open water. According to the U.S. Energy Information Administration, “The five states with the most electricity generation from wind in 2020 were Texas, Iowa, Oklahoma, Kansas, and Illinois. These states combined produced about 58% of total U.S. wind electricity generation in 2020.”

Although wind power is rapidly growing in the United States and around the world, it is not without its own difficulties. You have all heard some sort of drawback to wind power, whether it’s that turbines can harm wildlife, large projects are hard to get approval for or simply that they are an eyesore. We will be discussing some of these challenges to wind power in the coming ClimateRoots editions. For now, we hope this breakdown of wind energy blew your socks off (haha). Next week we'll be diving into the ins and outs of offshore wind!

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Bibliography

1. Electricity Generation from Wind - U.S. Energy Information Administration (EIA). https://www.eia.gov/energyexplained/wind/electricity-generation-from-wind.php. Accessed 25 July 2021.

2. “How a Wind Turbine Works.” Energy.Gov, https://www.energy.gov/articles/how-wind-turbine-works. Accessed 27 July 2021.

3. “How a Wind Turbine Works - Text Version.” Energy.Gov, https://www.energy.gov/eere/wind/how-wind-turbine-works-text-version. Accessed 25 July 2021.

4. “How Do Wind Turbines Work?” Energy.Gov, https://www.energy.gov/eere/wind/how-do-wind-turbines-work. Accessed 25 July 2021.

5. How Wind Turbines Generate Electricity | FWEE. https://fwee.org/nw-hydro-tours/how-wind-turbines-generate-electricity/. Accessed 25 July 2021.

6. Where Wind Power Is Harnessed - U.S. Energy Information Administration (EIA). https://www.eia.gov/energyexplained/wind/where-wind-power-is-harnessed.php. Accessed 26 July 2021.

Image source:

1. “Figure 1: Schematic Diagram of Wind Turbine System.” ResearchGate, https://www.researchgate.net/figure/Schematic-diagram-of-wind-turbine-system_fig1_344235652. Accessed 27 July 2021.