Together with solar power, wind power is set to become the key pillar of the renewable global energy supply.
Generating power from wind is not only carbon-neutral, it can be used to produce hydrogen and synthetic fuels like kerosene and diesel in a climate-friendly way.
With the sun, wind is so abundant that it has the potential to supply the entire global energy demand a few times over. This will be vital for the energy transition.
But what about the negatives? How much can wind turbines be recycled? And what about the impact on species, and especially bird life? What is the lifetime carbon footprint of wind power?
Building wind turbines is a very energy-intensive process, especially the production of the steel towers and the concrete foundations.
According to the German Environment Agency (Umweltbundesamt, UBA), wind power plants take between 2.5 and 11 months to generate the amount of energy that was needed for their construction.
On average, wind turbines are operated for about 25 years. During this time, they generate 40 times more energy compared to the energy required for the production, operation and the disposal of a wind power plant.
So-called upstream emissions, generated mostly through the production of carbon-intensive steel and cement, are included in the overall carbon balance of a wind turbine’s life cycle.
An onshore wind turbine that is newly built today produces around nine grams of CO2 for every kilowatt hour (kWh) it generates, according to the UBA. A new offshore plant in the sea emits seven grams of CO2 per kWh.
Compared to other technologies, wind power does well in terms of carbon emissions. By comparison, solar power plants emit 33 grams CO2 for every kWh generated. Meanwhile, power generated from natural gas produces 442 grams CO2 per kWh, power from hard coal 864 grams, and power from lignite, or brown coal, 1034 grams.
According to a study commissioned by the global anti-nuclear movement WISE, nuclear energy accounts for about 117 grams of CO2 per kWh, considering the emissions caused by uranium mining and the construction and operation of nuclear reactors.
Today, windsurfers can glide over water at speeds of over 90 kilometers per hour. This requires power, technique, good equipment and a lot of wind. Here at the Tokyo Olympics, Dutch windsurfer Kiran Badloe wins the gold medal.
Here in Novosibirsk, Russia, conditions are perfect for snowkiting — also known as kite skiing. The cold winters offer huge frozen areas and the wind blows strong. With the stunt kite once can reach very fast speeds of above 110 kilometers per hour.
Land sailing, also known as sand yachting, is performed in another wind-powered vehicle that can go very fast. In 2009, Richard Jenkins hit the highest speed on a land sail, reaching 203 kilometers per hour in Salt Lake in Nevada. Precursors are said to have existed in the windy north of China in the 6th century and in Europe from around the 17th century.
Greta Thunberg sailed the emissions-free racing yacht “Malizia” across the Atlantic in 2019. It took the then 16-year-old 14 days to cover the more than 5,300 kilometers from Plymouth in England to New York in the US. In doing so, the climate activist set an example for CO2-free travel. Electrical energy is generated on board the “Malizia” with solar panels and underwater turbines.
Hundreds of such mills existed in Spain in the 16th century in windy Castilla-La Mancha. The blades were covered with canvas to create a sail that once propelled by wind grinds flour. These Spanish windmills were famously depicted in novel Don Quixote when the confused title character picks a fight with the towers he believes are giants.
These windmills near Rotterdam in the Netherlands are masterpieces of engineering from the 18th century. Built to pump water from low-lying land, the resulting reclaimed swamp could be used for agriculture, meaning the wind-powered devices contributed to far greater prosperity in the region. Today, the wind pumps are UNESCO World Heritage Sites.
Modern power generation with wind began in 1980 in Palm Springs in California, where thousands of three-blade turbines were erected, Today, the oldest turbines have become a tourists site. Their minimal output of only 25 kilowatts compares to contemporary turbines with 500 times the output. Germany and Denmark were also at the forefront of modern wind technology, especially with offshore wind.
Two women with headdress observe a selfie in front of a modern wind turbine in Rong’an County, China. China has made an unprecedented push for wind power in recent years. In 2020, turbines with a capacity of 53 gigawatts were newly installed, which is equivalent to the output of 53 new nuclear power plants in one year.
Much research is currently being done on floating wind technology. This model turbine with two rotors is 18 meters high and is currently being tested in the Baltic Sea. The actual working turbine will be 180 meters high and have an output of 15,000 kilowatts. German energy company EnBW is investing heavily in the turbines and will test the first large-scale turbine off the Chinese coast in 2022.
Stunt kites can pull athletes and ships. This one in northern Germany generates electricity. During its ascent, the rope pulls on a winch with a generator. Once at the top, the kite is turned out of the wind and brought back with less energy, starting a new power generation cycle. The technology is being tested in cooperation with Europe’s largest coal company, RWE.
As Germany aims to phase out coal power by 2030 under a new commitment by the incoming coalition, wind-generated electricity will, with solar, become the biggest source of power. The trend is set to continue in other countries as well.
In the last three decades, wind power has grown exponentially. In 1991, 50 wind turbines with a capacity of 100 kilowatts were built in Germany. In 2001, another 2000 turbines had been added to the grid with a capacity of 1300 kilowatts.
When maintained well, these small-scale plants can operate for more than 30 years and can now be found in many countries.
Due to their long lifetime, only few old plants have yet been shut down and deconstructed. But by 2050, up to 50,000 plants will need to be replaced by newer and much more efficient wind power technology.
This will require the disposal of lots of concrete found in the foundation, steel in the tower and gear box,and a compound of plastic with glass- or carbon fiber used in the rotor blades.
The concrete can be crushed and used in road works. The precious steel can be recycled into new steel. Also other valuable metals like copper and aluminum can be reused.
Recycling the rotor blades made from plastic composites is more difficult. In the US, old rotor blades have so far ended up in disposal sites. In Europe, they have mostly been used as alternative fuel in cement kilns and waste incinerators.
The first recyclable rotor blades for large offshore plants are currently being produced in Denmark. From 2030 onwards, the plant constructor Siemens Gamesa plans to only sell recyclable rotor blades: from 2040 the production of the company’s wind power plants shall be completely carbon neutral.
Overall, a rapid expansion of wind power will help reduce CO2 emissions, helping to slow global warming and biodiversity loss.
Yet, some environmentalists demand that wind power plants not be installed in natural reserves or in migratory bird stopover sites so as not to endanger animals.
To combat this impact, an increasing number of large-scale wind power plants are also equipped with cameras and software technology that aim to avoid collisions with birds by switching off the turbines before they come too close.
Whales, seals and fish have also been disturbed by noisy construction works on the seabed when the foundations for offshore wind plants are built.
From a technical point of view, this problem has largely been solved via a ring of tiny air bubbles used during constructions activities that dampens noise by around 90%.
Offshore wind plants can even have a positive effect on sea animals since the respective area can no longer be used for trawl fishery, allowing fish stocks to recover. Moreover, the plants’ foundations become colonized by sea creatures such as mussels.
While warm summers are often windless, many places are stormy in the colder months and during winter.
Yet, this does not mean that wind power is threatened by climate change. Researchers believe that rising temperatures are not going to significantly lower global wind power.
While the jet stream located eight to twelve kilometers above sea level is slowed down by global warming, this does not affect the year-round energy yield of wind power plants.
Ultimately, wind capacity will be balanced out by rising temperatures: summers will be less breezy while future winters are predicted to be windier.
Wind power has been used for centuries. It pumps water, grinds grain, saws wood and brings sailing ships to their destination. In Europe, there were hundreds of thousands of wind turbines in the 19th century. The Dutch mainly used them to drain marshes. Today, wind power generates clean electricity and is central to meeting climate targets.
Wind turbines often generate the cheapest energy. Electricity from a new coal or nuclear power plant costs two to three times more today. Wind power generated on land is particularly cheap. According to forecasts, the cost of wind power will drop even further, to €0.03 ($0.04) per kilowatt hour (kWh) by 2030 in good wind locations.
A large wind turbine installed near Wilhelmshaven in northern Germany generates 6,000 kilowatts of power and covers the household electricity needs of 10,000 people there. Older models dating back 25 years, only achieved 500 kilowatts — enough for about 500 people. Modern turbines now stretch up to 180 meters into the sky. The taller they are, the more wind they catch.
At sea, the wind is reliable and strong. About 5% of the world’s wind power comes from offshore parks like this one off the Dutch coast. Turbines such as these have an output of up to 10,000 kilowatts. From 2025 their capacity is expected to rise to as much as 15,000 kilowatts and provide electricity for more than 40,000 people.
Half of all new wind turbines worldwide are currently installed in China. In 2020 alone, the country built new turbines with a capacity of 52 gigawatts of wind power. That is equivalent to the output of 50 nuclear power plants. The pioneers in wind expansion are Denmark and Germany. Denmark already covers about 50% of its electricity needs with wind power, while Germany achieves 25%.
About 1.3 million people work in the wind industry worldwide. About 550,000 of them are in China, 110,000 in the USA, 90,000 in Germany, 45,000 in India and 40,000 in Brazil. Installing and operating wind turbines is more costly than coal-fired power, so the expansion of wind power is creating more and more jobs.
In densely populated regions, wind power is often met with resistance. But this can change when citizens get involved in local projects. In Starkenburg, near the German city of Frankfurt, for example, many residents favor an expansion of wind power. They are investing in new turbines — and profit from the sale of electricity.
In the past, sailing ships carried freight all over the world, but then diesel engines took over. Now, modern sails are coming back into play. With additional wind propulsion, the energy consumption of freighters can be reduced by up to 30%. In addition, ships will be able to use green hydrogen as fuel in the future.
There is enough space in the sea for wind power. But in many places the water is too deep for a foundation in the seabed. Floating turbines on buoys are an alternative. They are fixed to the seabed with long chains. Floating wind farms already exist in Europe and Japan, and remain stable even during storms.
The 147-meter-high Strata SE1 skyscraper in London is an eye-catcher with futuristic wind turbines. But such rooftop installations are usually not economical, because the wind in cities is generally too weak. Photovoltaic systems on roofs are almost always the more efficient alternative.
Within 3 to 11 months, wind turbines generate the energy required to build them. No CO2 is produced in the electricity generation process but they do alter the landscape. Still, compared to other energy sources, they come off best in the environmental balance sheet. According to Germany’s Federal Environment Agency, their environmental cost is 70 times lower than that of coal-fired power.
Wind and solar power plants together can meet the world’s energy needs. Wind turbines generate electricity at wind speeds of 10 km/h and above. In regions with a lot of sun, photovoltaics is the cheapest energy source. A little further north and south of the equator, it is usually a mix of wind and solar power. In particularly windy areas, wind power can become the most important source of energy.