How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream

Prototype wind turbines whirl at a testing site in Osterild, near the northern end of Denmark’s Jutland peninsula. By Rasmus Degnbol

OSTERILD, Denmark — At the northern end of Denmark’s Jutland peninsula, the wind blows so hard that rows of trees grow in one direction, like gnarled flags.

The relentless weather over this long strip of farmland, bogs and mud flats — and the real-world laboratory it provides — has given the country a leading role in transforming wind power into a viable source of clean energy.

After energy prices spiked during the 1973 oil crisis, entrepreneurs began building small turbines to sell here. “It started out as an interest in providing power for my parents’ farm,” said Henrik Stiesdal, who designed and built early prototypes with a blacksmith partner.

The initial windmills made by small operations had quality problems. Blades — then just 15 feet in length — would break or fall apart.

Now, they are giants, made by global players pulling off enormous feats of engineering.

Technicians reach the roof of these enormous wind turbines either via an internal elevator or, if the turbine is installed offshore, by helicopters that lower them into the fenced-off area. By Rasmus Degnbol

The biggest turbines in Osterild stretch more than 600 feet high. The largest rotor blades can reach 270 feet in length, comparable to the wingspan of an Airbus A380, the world’s largest commercial plane. The price tag: Up to 10 million euros, or more than $12 million.

The monstrous scale has helped turn wind into a mainstream form of power.

Larger turbines harness more wind, creating more energy. The biggest modern offshore turbines produce nearly 20 times as much power as ones developed three decades ago.

The larger the size, the lower the cost of generating energy. In parts of northern Europe, wind is now a major power source. It accounts for 4 percent of overall global energy supply, according to the International Energy Agency.

Blades for wind turbines lie outside a factory, waiting to be transported to wind farms. By Rasmus Degnbol

From those early Danish innovators, the industry has grown to be dominated by companies like Vestas Wind Systems and Siemens Gamesa Renewable Energy.

The heart of the Siemens Gamesa business lies in Brande, a small Jutland town. It was there in the early 1980s that an entrepreneur named Peter Sorensen founded a wind business called Bonus with a couple of workers from his father’s irrigation company.

Siemens bought Bonus in 2004, and today, Brande is home to large engineering, training and maintenance hubs.

Staff sitting at consoles there can monitor wind farms around the globe. Often, when a problem shuts a turbine down, they can restart it electronically without needing to send a maintenance team.

At a cavernous workshop, technicians build custom turbine models and facilities for testing whether components are robust enough to last two decades or more. Inside, the towers are so big that elevators haul engineers up and down. Passengers must wear a climbing harness in case they fail.

The rotors are connected to the windmill tower by a nacelle — a large enclosure the size of a trailer, with plenty of room inside to walk around.

Looming over the top deck outside are the rotors. When they whirl, the whole column sways like a ship at sea.

Making these blades is difficult and labor-intensive.

Teams of workers gradually fill a mold with strips of fiberglass interlaced with balsa wood for strength. They then inject resins and other chemicals into the container to form the hardened structure.

The huge size of the blades, and the complexity of the process, mean completely automating it does not make economic sense. Around 1,300 people work in the factory, and making a single blade can take about three days.

It’s a difficult balance for manufacturers to achieve both size and efficiency.

The largest blades already weigh around 30 metric tons, and making them longer adds to their weight, fast. Overweight blades might lead to turbines being worn down faster, and would put enormous stress on other components.

A group of workers prepare a mold for a wind turbine blade. They fill the mold with fiber glass cloth in a process that loosely resembles making a surfboard. By Rasmus Degnbol

Designers are testing tweaks to the shape and size of a blade, experimenting with the changes in wind tunnels or on computers. They have found that gluing various add-ons to the blades can substantially boost performance.

One fix — a combination of serrated teeth and combs that reduced the sound of the blades — was inspired by the wing feathers of owls.

Many of the big turbines that are designed at the facility will eventually make their way to the open water, where there is more space and the wind is more powerful.

Their huge components, difficult to transport on roadways, can be loaded at ports onto special boats, which take them to sprawling wind farms in the sea.

The enclosures which connect the blades to the wind turbine’s tower are readied to be loaded onto ships. By Rasmus Degnbol

The first offshore wind farm was built using a barge that had a crane mounted on a truck. Companies today have developed specialized vessels to carry these offshore turbines to their floating platforms.

They must contend with a variety of challenges, including the corrosive impact of saltwater. To service wind farms far from the shore, maintenance crews sometimes live on special ships.

It’s a complicated calculus.

In the early years, building an offshore wind farm was fantastically expensive, and governments offered generous subsidies to help the industry develop. But prices have been falling, and government support has “melted away,” according to Andreas Nauen, the chief executive of Siemens Gamesa’s offshore wind division.

Lower costs, though, have also made wind power more appealing elsewhere. Once mostly concentrated in northern Europe, Mr. Nauen is optimistic that new markets will emerge in Asia and the United States.

“This is real,” he said.

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Zaha Hadid’s Desert Think Tank: Environmental Beauty and Efficiency

A small, jewel-perfect mosque at the desert end terminates the long, central courtyard, its ceiling covered by a filigreed, computer-generated pattern that recalls traditional arabesque motifs. The mosque is among the few anywhere designed by a woman.

A talent at least equal to her male competitors and a feminist role model for women, especially in the Arab world, Hadid represented a progressive wing of Arab culture. In a country where most women wear the veil and abaya in public, Hadid was more partial, actually, to fashions by Issey Miyake and Yoshii Yamamoto. Her victory in the competition dovetailed with the agenda of a king who, in 2009, founded the coed King Abdullah University of Science and Technology in Jeddah, where men and women mixed freely on an environmentally green campus, attending classes together.

Susan Kearton, a research center spokeswoman, said the center’s mission to find the most productive use of energy for economic and social progress aligns with “Vision 2030,” which the kingdom’s heir apparent, Crown Prince Mohammed bin Salman, recently put forward to diversify and develop the economy away from oil.


A central courtyard view, with the entrance in the distance. Credit Hufton+Crow

The research center was Hadid’s first design to be entirely driven on the basis of sustainability, but she did not surrender her design passport when she entered the competition. In a culture where architectural traditions can separate the sexes, Hadid used her characteristically fluid spaces to break down barriers and encourage social mixing. During Design Week last fall, women and men, students and princes mingled freely, sharing food and conversation in common spaces. Veils were optional.

When the project started in 2009, King Abdullah was already 85 and ailing, and there was strong pressure to complete the project in his lifetime. The research center leased a floor in an office building in central London, where at peak production 50 architects, 80 engineers and 20 members of the center’s staff worked together. The engineers crunched numbers as everyone produced thousands of drawings.

“Decisions were made very quickly,” Mr. Kang said. “We’d generate a system and give the design to engineers to simulate wind flows and sun penetration in many feedback iterations. The design was shaped as much by the environment as by the basic will of the designer.”

The King Abdullah Petroleum and Research Center was conceived as a legacy project for the king, but, sadly, it proved to be a double legacy, the king’s and Hadid’s. If the building achieves the stature King Abdullah wanted, it was not just another trophy in Hadid’s gallery of triumphs. Always open to change, she had moved on from her successes into new territories. In Riyadh, already in her 60s, she changed direction, becoming an architect she had never quite been, creating a design she had never quite done. Architectural beauty and sustainability were not mutually exclusive. Like her building, she adapted.

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Geothermal Energy Grows in Kenya

Across all of East Africa, there’s potential for some 20,000 megawatts of geothermal energy, according to a report from agencies including the Infrastructure Consortium for Africa and the United Nations Environment Program.

But Kenya and the surrounding region face many challenges to harnessing its full geothermal potential. Lack of funding and technical expertise, poor governance, and corruption often hobble big infrastructure projects in developing countries.

And though geothermal is considered renewable energy, it does have pitfalls. While the Earth will most likely supply heat for millions of years, the underground water necessary to produce steam can be depleted if not recharged.

Yet from a geological perspective, Kenya’s geothermal conditions are ideal.

“The amount of volcanism is amazing,” Mr. Suemnicht said. “It’s in the center of the action.”

The East African Rift is one of the world’s largest rift valleys, about 3,700 miles in length and 30 to 40 miles across. It is slowly splitting the African continent apart at the rate of several millimeters each year.

“Rift settings have very high potential for geothermal,” Mr. Suemnicht said. “Most geothermal development occurs in tectonically active areas on Earth.”

Kenya is by far Africa’s geothermal leader, but nations such as Tanzania, Uganda, Rwanda, Djibouti, Eritrea and Comoros have done preliminary exploration and Ethiopia generates about 7 megawatts of geothermal power.

Tapping geothermal energy is a long and expensive process that requires special expertise. From start to finish, it can take years from site-scouting to construction to connection to actually generating electricity — and revenue.

To find suitable spots for drilling steam wells, scientists do geological, geochemical and geophysical surveillance, a process that can take three months, said Xavier Musouye, a geologist with KenGen. When suitable spots are found and assessed, drilling begins using the kind of tall rigs commonly seen at oil wells. Except for periodic maintenance breaks, these drills pound into the earth 24 hours a day for nearly two months.


Bathing in a natural spa that draws its mineral-rich water from condensed steam at the Olkaria geothermal power generation complex in the East African Rift. Credit Amy Yee

At a new well site in Hell’s Gate, the noise was deafening as gargantuan machinery pummeled the ground. The well will eventually reach a depth of almost two miles, joining the nearly 300 others already in place in the park.

It can cost about $6 million for a single well, and even with all the planning and testing there is still a risk of drilling an empty well. Two geothermal wells were explored in neighboring Rwanda but were unsuccessful, noted Dr. Meseret Zemedkun, energy program manager for the United Nations Environment Program.

Although it is a time-consuming process, there have been advancements to speed things along. KenGen recently started using a new kind of small power plant directly on the well head that can get up and running more quickly. These generate 7.5 megawatts compared with the large power stations that each generate 45, 105 and 140 megawatts.

Kenya, the first African country to tap geothermal power, began its programs in the late 1970s and early 1980s through funding primarily from the World Bank and guidance from the United Nations Development Program. But funders pulled out in the early 1990s amid government instability before returning toward the end of that decade.

The growth since then has been dramatic, and continues. KenGen is in the process of building a new 140-megawatt plant, financed by a $400 million loan from JICA, Japan’s development agency, that is expected to start running by 2018.

Although geothermal power has led to rapid expansion of electrical service here, there are environmental trade-offs. There is the conundrum of drilling in Hell’s Gate, a 26-square-mile area that is one of the country’s smaller parks but has been designated a Unesco world heritage site. Some environmentalists are critical of extracting geothermal energy here. They complain that pipes and power plants are environmentally disruptive and an eyesore.

Elizabeth Mwangi-Gachau, chief environmental officer for KenGen, said the company conducts environmental assessments and tries to mitigate impact. It considers wildlife migration and behavior in its development plans. Ms. Mwangi-Gachau added that KenGen has refrained from drilling in parts of Hell’s Gate that would compromise the flora and fauna, even where there is major geothermal potential.

Ms. Zemedkun of U.N.E.P. pointed out that environmentally friendly geothermal projects have been developed around the world — even within national park areas, including in the United States, Italy, Iceland, New Zealand and Japan.

At Hell’s Gate, the otherworldly network of geothermal pipes can be an attraction for some tourists. KenGen has even opened a geothermal spa, following the lead of an Icelandic power company that opened the Blue Lagoon spa, a signature attraction that uses water harnessed by a nearby geothermal power plant to warm its pools.

On a sunny afternoon, groups of Kenyans basked in the spa’s azure water. They weren’t fazed by the sight of steel pipes at a nearby geothermal wellhead. Overhead, odorless white steam floated into the air to mingle with the clouds streaking the Kenyan sky.

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