LONDON – If there is one word that can be associated with wind energy, it is “big”. From business worth billions to huge wind farms that can power a million households, the industry has seen massive expansion in recent years.
According to a recent report by the Global Wind Energy Council, the sector installed 93 gigawatts (GW) of new capacity in 2020, a record high that represents a jump of more than 50% from the previous year. In the past ten years, the global wind power market has almost quadrupled.
As the industry grows, so do the turbines that power it. In Europe, figures from the industry association WindEurope show that the average capacity of the offshore turbines installed in 2020 was 8.2 MW, which corresponds to an increase of 5% compared to the previous year.
In the past few years, several original equipment manufacturers or OEMs have announced plans to develop new large turbines for the offshore sector – and the size of these new machines is considerable.
For example, GE Renewable Energy’s Haliade-X turbine will have a top height of 260 meters, 107-meter blades and a 220-meter rotor. The output can be configured to 12, 13 or 14 megawatts (MW). A prototype of the Haliade-X in the Netherlands has a top height of 248 meters.
Details on GE’s Haliade-X were released in March 2018. In recent years, other large companies in the industry such as Vestas and Siemens Gamesa Renewable Energy (SGRE) have introduced designs for similar sized turbines.
“You could see a quantum leap in the technology architecture and technology specifications of the turbines,” said Shashi Barla, principal analyst at Wood Mackenzie, CNBC in a telephone interview.
Competition within the industry is sure to intensify. In February Vestas announced plans for a 15 MW turbine. A prototype is to be installed in 2022 and production is to be expanded in 2024.
For its part, SGRE is working on a 14 MW model, the SG 14-222 DD, which can also be increased to 15 MW if necessary.
Here, too, the dimensions of these turbines are large: the Vestas turbine will have a blade length of 115.5 meters and a rotor diameter of 236 meters. SGRE’s design includes 108-meter blades and a rotor diameter of 222 meters.
The nuts and bolts
The size and scope of these new designs may be impressive, but they also have a practical purpose.
For example, when it comes to altitude, a taller turbine can take advantage of faster wind speeds and produce more electricity.
A primer recently released by Bank of America Global Research found that turbine blades “have grown much longer in the past 5 to 6 years, giving turbines a larger” swept area “and thus more wind capture”.
“Larger blades also allow wind turbines to run better in locations with low wind, which opens up more locations for installations,” the note added.
The size of the rotor is also critically important, a point Wood Mackenzies Barla was keen to highlight. Increasing the diameter of the rotor of a turbine has a bigger impact than increasing its height, he argued, “because the area swept increases and (when) the area swept increases, you’re using more energy.”
The size of these components is not for illustrative purposes only. It is hoped that larger turbines will help reduce Levelized Energy Costs (LCOE), an economic assessment of the total cost of a power generation system over its lifetime.
Logistics, logistics, logistics
It’s all well and good to build huge turbines, but getting massive blades, towers, and rotors where they need to be can be a huge headache.
Transporting a tower’s components can often be hampered if they are too large to fit under freeway flyovers or bridges, according to the DOE.
Blades, for example, are a potential sticking point when it comes to logistics.
“Once a blade is fully constructed, it can no longer be bent or folded,” says the DOE. This “limits both the route a truck can take and the radius of turns it can make, and often requires longer routes to avoid urban roadblocks.”
In a telephone interview with CNBC, Feng Zhao, Head of Strategy and Market Information at the Global Wind Energy Council, briefly summarized the challenge. “If you can’t get the components to the site, you won’t be able to build.”
Wood Mackenzies Barla made a similar point. “The biggest limiting factor in scaling the technology is not the technology itself, but the logistics,” he said.
“As you increase component size, logistics costs go up dramatically, especially for … components like blades and towers.”
As the planet seeks to reduce its dependence on fossil fuels and use renewable energies, wind power will play an important role.
The Biden government aims to expand US offshore wind capacity from just 42 MW today to 30 GW by 2030, while the European Union is aiming for at least 60 GW by the end of the decade and 300 GW by 2050.
And when it comes to turbines, they only get bigger, especially offshore.
“The peak heights of next-generation offshore turbines will rise to 300 meters over the next decade,” Wood Mackenzie’s Barla told CNBC via email.