What Is Wind Energy How Does It Work And What Are Its Advantages?

Wind energy is a form of renewable energy that is generated using naturally occurring wind flows to turn turbines and produce electricity. Wind turbines convert the kinetic energy in wind into mechanical power, which is then converted into electricity that can power homes, businesses, schools, and more.

People have been harnessing the power of wind for thousands of years. Wind was used to propel boats along the Nile River as early as 5000 B.C. By 200 B.C., simple windmills were used in China to pump water and grind grain. Windmills were later adopted in Europe during the Middle Ages for similar purposes. It wasn’t until the late 19th century when the first wind turbine for electricity generation was built.

Today, wind power is one of the fastest growing renewable energy sources globally. Improvements in turbine technology along with government incentives have enabled wind energy capacity to expand rapidly. As of 2020, installed global wind power capacity reached around 743 GW.

How Wind Turbines Work

Wind turbines convert the kinetic energy in wind into mechanical power that runs a generator to produce electricity. Here is how they work:

When the wind blows, it passes over the blades of the turbine. The aerodynamic shape and angle of the blades causes lift, which makes the rotor (the part with the blades) spin. The rotor is connected to a drive shaft that turns when the blades spin. The drive shaft is connected to a gear box which speeds up the rotation. This mechanical power from the spinning shaft drives the generator and converts the rotational energy into electrical energy through electromagnetic induction. The electricity is then sent through transformers and transmission lines to homes, businesses, and the utility grid.

The generator inside the turbine works similarly to a bicycle dynamo. It contains magnets that spin around wire coils to generate alternating current (AC) electricity. The rotating magnetic field induces voltage in the coils, creating an electric current. More wind energy spins the turbine blades faster, which spins the drive shaft and generator faster to produce more electricity.

So in summary, wind turns the turbine blades, which spin a shaft connected to a generator to create electricity. Wind turbines effectively convert kinetic wind energy into usable electrical power with no emissions, serving as a clean renewable energy source.

Wind Energy Resources

Wind energy can be harnessed in many locations, but the best sites are in areas with consistent annual wind patterns. Wind speed and consistency are key factors in identifying prime locations for wind farms. Offshore and onshore sites both have advantages and disadvantages.

Offshore wind farms can harness stronger and more consistent winds because there are fewer obstructions over water. However, constructing offshore turbines is more expensive than building on land. Operations and maintenance costs are also higher for offshore facilities due to transportation, accessibility issues, and corrosive effects of the saltwater environment.

Onshore wind farms do not face the same transportation and accessibility challenges. However, land-based wind patterns can be interrupted by forests, buildings, hills, and other obstructions. Farmers and residential communities may also oppose construction of wind farms near their properties due to noise, viewshed impacts, and other concerns.

By carefully evaluating wind data, energy companies can identify sites with the optimal combination of strong, steady winds, affordable construction costs, and community acceptance. Many prime onshore wind farm locations are in the plains states, while offshore sites are concentrated mainly on the coasts.

Wind Turbine Components

Wind turbines are made up of many components that work together to convert wind energy into electricity. The main components include:

Blades

The blades are made of composite materials like glass fiber reinforced plastic. Their aerodynamic shape allows them to capture the kinetic energy of the wind. Blades are getting larger, some over 100 meters long, to capture more wind energy.

Tower

Towers are made of tubular steel, concrete, or steel lattice. They can be over 100 meters tall to reach greater wind speeds at higher heights. Taller towers also allow longer blades to be used.

Nacelle

The nacelle sits atop the tower and contains the gearbox, generator, controller, brakes, and other components. It is designed to withstand high winds and harsh weather conditions.

Generator

Most large wind turbines use a high speed shaft and gearbox to drive an AC synchronous generator that produces electricity. Newer direct drive generators eliminate the gearbox and operate at lower speeds.

Yaw System

This allows the nacelle to turn and face into the wind. It uses a bearing and electric motors to keep the rotor blades perpendicular to the wind, maximizing energy production.

Wind Energy Capacity

Wind energy capacity has grown substantially in recent years. As of 2021, global installed wind power capacity was around 837 gigawatts (GW). The countries with the highest installed capacity are China, the United States, Germany, India and Spain.

China leads the world with over 350 GW of installed capacity, representing over 40% of the global total. The U.S. has around 122 GW of installed capacity. Germany, a pioneer in wind power, has over 62 GW installed. Other leading countries include India (40 GW), Spain (28 GW), the UK (26 GW) and France (18 GW).

Global wind power capacity increased more than tenfold between 2000 and 2020. Annual installations of new wind power capacity have accelerated in recent years, reaching around 93 GW of new capacity added globally in 2020. The offshore wind power market has grown rapidly, with around 35 GW of total offshore capacity at the end of 2020.

Wind power is projected to grow strongly in the coming decades to meet increasing electricity demand and climate change targets. The Global Wind Energy Council projects global wind capacity will reach around 2,110 GW by 2030. Continued growth is expected in major markets like China and the U.S., as well as emerging markets with strong wind resources.

Wind Energy Costs

The costs associated with wind energy include both the initial capital costs of constructing the wind farm as well as the ongoing operating and maintenance costs. The capital costs include expenses such as feasibility studies, purchasing land, installing wind turbines and electrical equipment, grid connections, and other infrastructure. Operating costs involve regular maintenance, repairs, insurance, and management fees.

The average total cost of developing a new wind farm in the U.S. ranges from $1,500 to $2,500 per kW of capacity. Therefore, a 250 MW wind farm would require $375 million to $625 million in capital costs. The operating costs amount to $20-25 per MWh. This means a 250 MW wind farm generating around 650,000 MWh per year would have annual operating expenses of $13-16 million.

In terms of cost-competitiveness, wind energy is becoming increasingly affordable compared to conventional fossil fuels. The costs have declined dramatically in the past decade. New wind farms built today are generating power at 3-6 cents per kWh, making wind cost-competitive with new plants fueled by natural gas or coal. The operating costs of wind turbines are also minimal compared to conventional plants. As technology improves, capacity factors increase, and more projects utilize economies of scale, wind energy is projected to become even more cost-effective.

Wind Energy Benefits

As a renewable energy source, wind power offers many advantages. One of the key benefits is that wind is an abundant, infinite resource that is not depleted when harnessed for electricity generation. Unlike fossil fuels which are finite, wind can be captured whenever it is available.

Generating electricity from wind also reduces harmful greenhouse gas emissions and air pollution. Wind turbines produce no carbon emissions during operation, helping combat climate change. Each megawatt-hour of electricity generated by wind replaces over 1,600 pounds of carbon dioxide that would otherwise be produced from burning fossil fuels.

In addition, wind power contributes to local economies by providing jobs and revenue. Wind farm development, construction, maintenance and other wind-related services employ workers. Wind projects also generate tax revenue and land lease payments for local communities and landowners. With wind power, money spent on electricity stays in the local economy rather than being transferred out of state to purchase fossil fuels.

Wind Energy Challenges

While wind energy offers many benefits, expanding its use does come with some challenges that need to be addressed.

Intermittency/Variability

The wind doesn’t blow consistently, which means wind turbines produce variable amounts of electricity based on wind speeds. This variability can present challenges when integrating large amounts of wind energy into the grid. Steps like improving wind forecasting, increasing grid interconnections, using energy storage, and implementing demand response help manage wind’s variability.

Land Use Conflicts

Large-scale wind farms require a lot of land, which can sometimes conflict with existing land uses like agriculture or conservation areas. Careful wind farm siting, minimizing land disturbance during construction, and using scanning radar to avoid protected wildlife areas can help reduce land use conflicts.

Bird and Wildlife Impacts

Wind turbines can pose a risk to birds and bats through collisions. Proper siting away from major migration routes and buffered habitat areas along with technological solutions like ultrasonic acoustic deterrents can reduce wildlife impacts. Continued monitoring and research helps make wind farms more wildlife-friendly.

Wind Energy Policies

Government policies play a major role in supporting the growth of wind energy. Policies like subsidies, tax incentives, and renewable energy standards help make wind power more affordable and competitive with conventional sources of electricity generation.

Many governments provide subsidies and tax incentives for wind energy projects and production. These financial incentives help reduce the cost of wind power and encourage investment in wind farms. Common subsidy programs include production tax credits, investment tax credits, loan guarantees, and cash grants. These incentives allow wind farm developers to secure financing for projects and can account for 30% or more of project costs.

Renewable portfolio standards (RPS) are policies that require electric utilities to source a certain percentage of their electricity from renewable sources. As of 2021, RPS policies existed in 30 U.S. states. These standards create guaranteed demand for wind energy and provide long-term certainty to the industry. Utilities typically turn to wind power as one of the most cost-effective options for meeting RPS requirements.

Government policies will continue to play a pivotal role in spurring wind energy deployment going forward. Extending tax incentives, implementing national clean energy standards, updating grid infrastructure, and streamlining permitting processes are some examples of supportive policies.

Future of Wind Energy

Wind energy is poised for significant growth in the coming decades due to improvements in technology, expansion into offshore locations, and its key role in the global energy transition.

On the technology front, turbine designs are evolving to capture more energy, become more reliable and efficient, and provide greater flexibility to grid operators. Larger rotors, taller towers, intelligent control systems, and robust gearless generators will enable wind turbines to maximize energy production. New materials like carbon fiber may also enable blade designs that are longer, lighter and more durable.

Offshore wind development is also accelerating, especially in Europe, Asia and North America. Floating turbine foundations will allow wind farms to move into deeper waters further from shore. According to the International Energy Agency, global offshore wind capacity may increase 15-fold to reach 235 gigawatts by 2030.

Lastly, wind power will play a central role in the transition away from fossil fuels. Wind and solar energy are now the cheapest sources of new electricity generation in many markets. As governments and companies work to decarbonize the world’s energy systems, onshore and offshore wind power can provide carbon-free electricity at scale. The IEA projects wind capacity may rise to nearly 2,400 gigawatts globally by 2030 under a path to net-zero emissions.