Europe needs ports to help fulfill its ambitious plans for increasing the production of offshore wind energy — and Esbjerg is one of the biggest. The Danish city is becoming a model of well-planned energy production.
On-shore wind turbines are being tested near the Danish port of EsbjergImage: Oliver Ristau/DW
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May 18, 2022, was a memorable day for Jesper Frost Rasmussen. It was the day four European heads of state and the president of the EU Commission came to Esbjerg to sign a strategy paper on the expansion of offshore wind energy.
Together, the countries want to increase wind energy production in the North Sea to 65 gigawatts (GW) by 2030, rising to 150 GW by 2050. A framed copy of the Esbjerg Declaration— signed by German Chancellor Olaf Scholz, Danish Prime Minister Mette Frederiksen, and the prime ministers of Belgium and the Netherlands, Alexander de Croo and Marc Rutte — hangs on the wall in Rasmussen's office.
Rotor blades on the quays
Rasmussen is the mayor of Esbjerg. He knows that his city has a key role to play in the plans. Esbjerg is one of the few European ports that serve the offshore wind industry. Industry giants such as Vestas and Siemens Gamesa ship wind turbines from here, and the electricity producer Örsted supplies around 25 offshore wind farms with spare parts like gearboxes, generators and hubs. The parts can each weigh several tons.
Jesper Frost Rasmussen, the mayor of Esbjerg, knows that his city has a key role to play in Europe's wind energy plansImage: Oliver Ristau/DW
The quays are big enough — even for the massive turbine rotor blades, which are stacked and waiting to go. Without infrastructure like this, Europe's high-flying offshore dreams would never become reality.
German ports, on the other hand, are languishing in the doldrums. In Bremerhaven, a dispute over the development of an offshore wind port lasted for years, ending up in court. Meanwhile, some companies in the sector, such as Prokon, Senvion and Windreich, went bankrupt. Not much is happening at other German ports, either. Only the much smaller Dutch port of Eemshaven is involved. Foundations for the giant offshore turbines are already being shipped from here.
'We're all pulling together'
Esbjerg has picked the right moment. For decades, energy generation in the North Sea was dominated by the construction of oil and gas platforms. Now, wind energy is taking over. One in nine jobs in Esbjerg is already directly dependent on wind power — that's around 5,000 in total.
Siemens rotor blades and mast elements for wind turbines at a storage facility in EsbjergImage: Christian Charisius/dpa/picture alliance
"We're all pulling together on wind energy," says Mayor Rasmussen, a member of Denmark's Liberal Party. "As a city, we make sure the industry gets the sites it needs." As an example, he explains that the municipality recently decided to extend the harbor by 500,000 square meters (5.4 million square feet), to a total of 4.5 million square meters. Environmental groups were also involved in the planning: "There was no dissent on the issue."
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Gigawatt hydrogen plans
Planning is well underway for sites that will produce green hydrogen. Part of the steadily growing volume of wind power that arrives in Esbjerg via submarine cables will be used for the electrolysis of hydrogen. For example, the Swiss project developer H2Energy plans to build a 1 gigawatt (GW) electrolyzer on the outskirts of the port by 2024, which will split water into its component elements, hydrogen and oxygen. This electrolyzer would be one of the largest in the world.
And there's more. The Danish investment company CIP plans to build another 1 GW plant nearby. When it goes online, it will use wind-generated hydrogen to synthesize 600,000 tonnes of "green" fertilizer per year.
World's biggest marine source heat pump
Meanwhile, Christian Udby, CEO of local utility company DIN Forsyning, is already thinking of the next step in the renewable energy chain. "In future, we want to use the waste heat from the electrolyzers for district heating," he says. His company needs to take action, because the port's coal-fired power plant, which until now has supplied around half the city's heating, is due to be taken off grid on April 1, 2023.
Esbjerg is building the world's biggest marine source heat pump, which will extract heat from seawaterImage: Oliver Ristau/DW
A broad mix of alternatives is set to take over. The main one, in addition to biomass, is a 50-megawatt (MW) marine source heat pump, which is currently under construction in the port. The largest of its kind in the world, it will draw water from a harbor basin, extract heat, then discharge the water back into the North Sea, farther off. The technology is being supplied by German companies MAN and Volkswagen.
It will be the first time this innovation has been launched commercially in Denmark, and will have taken barely five years, from the initial idea until the start of operations. Hamburg also has ambitious plans to replace a coal-fired power plant: River source heat pumps have been under discussion there for far longer. However, it will take a few more years before the project is implemented there.
The future of wind power
Wind is becoming increasingly important for electricity generation — and turbines are getting bigger, taller and more efficient. About 7% of the world's electricity already comes from wind power. What's next?
Image: Jan Oelker
Then and now
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.
Image: picture-alliance/ImageBroker/J. Tack
Wind beats coal
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.
Image: picture alliance / Zoonar
20 times more electricity
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.
Image: Ulrich Wirrwar/Siemens AG
Giants in the sea
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.
Image: Siemens Gamesa
China leads the way
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.
Image: Paul Langrock/Siemens AG
Citizens want to profit
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.
Image: Energiegenossenschaft Starkenburg eG
Sails save diesel
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.
Image: Skysails
Floating wind farms
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.
Image: vestas.com
Wind power for homes
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.
Image: picture-alliance/Global Warming Images/A. Cooper
Most environmentally-friendly energy
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.
Image: picture-alliance/dpa/J. Tack
Where to put wind 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.
