Wind Energy is one of the booming clean energy technologies. According to IRENA’s latest data, global installed wind-generation capacity onshore and offshore has expanded by about 75 times in the last two decades, from 7.5 gigawatts (GW) in 1997 to 564 GW in 2018.
Ever wondered how those massive rotating turbines powered up an entire locality? Join me on this journey to a wind farm exploring the wind turbines, their working, advantages and disadvantages. Let’s get started
What is Wind Energy?
Wind energy or wind power refers to the process of using the wind to generate mechanical or electrical power. This mechanical energy can be employed for specialized purposes such as pumping water or it can be converted to electricity using a generator.
A wind farm is a collection of wind turbines that are all located in the same area. A huge wind farm can include hundreds of separate wind turbines spread out over a vast region. The Gansu Wind Farm is the world’s largest wind farm. We can utilize the land between the turbines for farming or other activities. In a fully established wind farm, we place a distance of 7D (7 times the rotor diameter of the wind turbine) between each turbine.
Individual turbines in a wind farm are linked by a medium-voltage power gathering system and a communication network. This medium-voltage electric current is boosted in voltage by a transformer at a substation before being connected to a high-voltage electric power transmission system.
Let’s understand the working of a wind turbine.
Working of Wind Turbine for Wind energy
The aerodynamic force from the rotor blades, which act similarly to an aeroplane wing or helicopter rotor blade, converts wind energy into electricity in a wind turbine. The air pressure on one side of the blade lowers when the wind blows across it. This difference in air pressure across the two sides of the blade generates lift and drag.
The lift force is greater than the drag force, causing the rotor to spin. The rotor is connected to the generator directly or through a shaft and a series of gears that speeds up the rotation. The conversion of aerodynamic force to the generator’s rotation generates power.
Equation for Wind Power
The power that a wind turbine generates, P = 0.5 DAV3
where D = Density of the air
V = Wind Speed
A = Swept area of the turbine
Let me explain in detail how each parameter affects wind power.
The quantity of energy in the wind is proportional to the cube of the wind speed; ie, if the wind speed doubles, the amount of energy in the wind increases by eight times. Hence we can understand that wind speed fluctuations have a significant impact on the quantity of power available in the wind.
Density of Air
The denser the air, the greater the energy the turbine receives from the wind. The density of the air changes with altitude and temperature. Higher elevations have less dense air than sea level, while warm air has less density than cold air. Turbines will produce greater power at lower elevations and in areas with cooler average temperatures, assuming all other factors are equal.
The swept area of the turbine
The larger the swept area which is the region through which the rotor rotates, the more wind power the turbine can capture. Since swept area (A= pi*r2) is proportional to the square of the radius of the rotor, a slight increase in the length of the blade length leads to a greater increase in the power available to the turbine.
Wind Energy Advantages
Wind energy is a cost-effective choice for many places of the world because it does not require direct sunshine exposure like solar energy. It offers several advantages such as:
There is no need for extra fuel since wind turbines run only on the power supplied by the wind. After mounting a turbine it does not need to be fueled or connected to power to continue working. This lowers the overall cost of maintaining large-scale wind farms.
Clean source of energy
Wind energy does not contribute to global warming and climate change by producing greenhouse gases during energy generation because it does not rely on fossil fuels to power the turbines. Wind energy only emits greenhouse gases indirectly during the production and transportation of wind turbines, as well as during the installation process. In the long term, this amounts to very low emissions.
Doesn’t Affect Farming Operations
Wind turbines can be built on pre-existing farmland. Energy providers can pay farm owners to build wind farms on their land through contracts or leases. As wind turbine footprints take up very little ground space, it won’t interfere with the farm’s produce. Offshore windfarms helps in saving space.
Reduces our dependence on fossil fuels
Energy from fossil fuel not only contributes to climate change, but it will also run out one day. There is an unlimited supply of wind as long as the sun heats the planet.
Wind Energy Disadvantages
Although wind energy is a renewable and environmentally friendly source of energy, it still has drawbacks and limitations.
Wind turbines can harm wildlife. The blades of wind turbines can harm or kill the flying birds and bats that come into contact with the blades. Aside from wildlife that soars through the air, noise pollution from spinning blades may have an impact on animals on the ground.
Since wind turbines can be rather noisy, we can mount them only in remote places where few people dwell. Noise isn’t a concern in the case of offshore turbines. As technology advances, we have newer designs that lessen noise issues and offer a much quieter presence.
Expensive Initial Investment
Wind turbines are gigantic structures that are often hundreds of feet tall and demand significant initial investment. The installation of wind turbines in rural areas necessitates additional investment in underground lines to transport power to more populated areas such as towns and cities.
Unreliable and Unpredictable
Wind energy is subject to intermittency, which is a disturbance due to the wind’s inconsistency. Since wind can blow at different speeds, it’s difficult to anticipate how much energy it can deliver at any particular time. This means that suppliers and towns must have an energy reserve or alternate sources of power. This is in the event that the winds stop blowing for an extended period of time.
Wind Energy Future
Wind energy can assist in the production of green hydrogen and green ammonia which are future fuels. This will hasten our rate of energy transformation and reduce the necessity for large-scale, high-cost oil exports.
When we combine all benefits of wind energy and solar energy, we are on our way to realising the full potential of renewable energy through wind-solar hybrid projects. These initiatives will boost efficiency while also ensuring power continuity and consistency. Check out our blog Solar Energy- Definition, Advantages and Future to know more about solar energy.
Shall we wrap up?
Wind is caused by the uneven heating of Earth by Solar radiation. Hence wind energy is an indirect form of solar energy. By tapping into this huge energy source alone or in conjunction with solar energy we can reduce our dependence on fossil fuels and save ourselves from the impending energy crisis. Let’s switch to wind energy for a better tomorrow.