Inside a Wind Turbine: Up Close and Personal
 Topic: Inside a wind turbine |  Read Time: 6 mins |
 Landowner type:Independent landowners | Institutional landowners | Professional advisers | Site Operator |  Energy: Onshore wind |
30th August 2024Have you ever wondered what lies inside a wind turbine? Join me as I look into its interior and uncover precisely what makes these enormous structures tick.
While wind turbines might look like simple structures from the outside, there’s a lot going on beneath the surface. Peek under the nacelle and you’ll find everything from gearboxes and generators to brakes, shafts and yaw systems.
But what exactly do these mechanical feats of engineering actually do to help a turbine produce wind energy? And how do wind turbines work? Here, I answer both of those questions and more.
What’s Inside a Wind Turbine?
Nacelle
Before we explore the inside of a wind turbine, we’ll need to examine the nacelle, which holds several critical mechanical components.
This turbine section sits behind the rounded hub and contains the gearbox, generator, break and shafts. Large, utility-scale nacelles can be enormous, stretching to around 50 feet and weighing around 60 to 80 tonnes, depending on the turbine’s configuration.
The largest nacelle in the world belongs to the Haliade-X 12 MW turbine, which is 207 metres high and has a net weight of 675 tonnes. These nacelles need to be relatively roomy to house several complex parts of the turbine.
Gearbox
The turbine’s gearbox connects the low-speed shaft to the high-speed shaft and increases the rotational speed of the turbine.
It can increase the rotational speed of an average turbine from around 8 to 20 rotations per minute (RPM) to anywhere between 1000 and 1,800 RPM. So, it’s a vital part of creating enough mechanical energy to convert to electrical energy that we can use across the country.
The gearbox must withstand quite demanding pressures from the system, including changing temperatures, loads and vibrations. So it’s usually very strong.
Generator
Once the gearbox has worked its magic, the generator inside a wind turbine comes into play.
This device converts the kinetic energy of wind into usable electrical power that’s carried through to transformers and substations. The high-speed shaft drives the generator, which uses copper windings to turn through a magnetic field. This action produces renewable energy in the form of alternating current (AC).
Brakes
Turbine brakes essentially stop the rotor from turning if the pitch system has shut it down. The brakes keep the turbine blades from moving and prevent the system from operating during inclement weather or maintenance periods.
But the beauty of the braking system is that it slows the blades down to stop them in a reasonable timeframe to prevent damage in an emergency. The braking process takes time but can be quick enough to manage most risks. A total stop usually occurs within a few blade turns but may take slightly longer for larger, heavier turbines.
If a wind turbine typically runs at lower speeds, you don’t always need to use the same powerful brakes that high-speed turbines use. Instead, smaller turbines often have a disk brake that relies on a torque to stop.
For high-speed turbines, the brakes work by engaging the generator to alter the movement of the turbine. By changing the turbine’s rotational speed, there’s a massive reduction in the output torque and an overall decrease in speed.
Main shaft
The main shaft of a wind turbine supports the rotating low-speed shaft. It reduces friction between all moving parts inside the turbine and ensures the turning forces don’t cause damage. The main shaft is usually arranged in a geared, hybrid or direct-drive design.
Direct-drive turbines are the most innovative option on the market, as they don’t require a gearbox. They use the main shaft as a generator and are typically larger than geared or hybrid models.
The main shaft usually spins at around 30 to 60 RPM, and the generator is responsible for boosting its speed considerably. The slower-rotating main shaft is connected to a high-speed shaft via the gearbox, which uses several gears to accelerate the rotation process.
Yaw motor and drive (AKA: the yaw system)
The entire yaw system rotates the nacelles to keep them facing the direction of the wind. So they’re critical for boosting output as they keep the turbines in an optimal position for processing the wind that hits them.
The yaw drive orients the wind turbine, while the yaw motor powers it. Together, they work seamlessly to keep the turbine functioning optimally and capturing the maximum kinetic energy available.
You’ll typically only find yaw systems on horizontal-axis wind turbines, because vertical-axis turbines have their blades perpendicular to the wind speed. So no specific orientation is needed.
Anemometer
Many onshore and offshore wind turbines have an anemometer that measures wind speeds.
The figures the anemometer transmits back to the controller often include average speeds, along with minimums and maximums for comparison over time. The anemometer counts the number of rotations a turbine makes each second to calculate the average wind speed in the area.
Site operators often use anemometers to measure a turbine’s performance, but they can also determine the direction of wind hitting the turbine. If the turbine isn’t working to its full potential, site operators can use the yaw system to alter the direction of the nacelle.
Pitch system
A pitch system works with the yaw system to optimise power production by controlling the rotor speed and adjusting the angle of the turbine blades. By changing the angles, the pitch system can increase or decrease the energy the turbine extracts from the wind.
Controller
The controller is a crucial part inside a wind turbine that allows a machine to start and stop at ideal wind speeds. It usually kicks in when wind speeds hit around 7 mph, but it’s also designed to shut off if wind speeds exceed more than 55 to65 mph.
This control measure prevents any damage to the turbines in a storm by preventing the blades from spinning too quickly. When the winds calm down, the turbine can start again.
Want to Install a Wind Project?
If you’re interested in getting turbines on your land, contact the Lumify Energy team. We’ve seen our fair share of leases, payment arrangements and option agreements, and so we can guide you through the wind farm process from beginning to end.
Whether you’re considering a wind farm or are committed to making passive income from your acreage, we can help. And if you need clarification on your site’s suitability for wind power, we can even compare your site to similar ones around the UK to give you an idea of what you could earn.
