Wind energy is booming in the United States; the country’s renewable energy capacity has more than tripled in the last nine years, thanks mostly to wind and solar power. Businesses now want to harvest even more wind energy at a reduced cost, and one of the most cost-effective methods to do so is to build larger turbines. That’s why, with a height of 500 metersnearly a third of a mile and 57 meters higher than the Empire State Buildinga group of six institutions led by University of Virginia experts is designing the world’s tallest wind turbine.
Turbines are much bigger now than they were 15 or 20 years ago. Wind farm towers vary in size, but most are roughly 70 meters tall and have blades that are about 50 meters long. Their power production varies depending on size and height, but it usually falls between one and five megawattsenough to power around 1,100 households on the higher end. “The drive to go to larger wind turbines is largely economic,” says John Hall, an assistant professor of mechanical and aerospace engineering at the University of Buffalo, S.U.N.Y. Wind blows stronger and more persistently at higher elevations, which makes huge turbines more cost-effective. As a result “According to Eric Loth, project head of the enormous turbine project, which is sponsored by the US Department of Energy’s Advanced Research Projects AgencyEnergy (ARPAE), “you capture more energy” with a taller structure.
Another reason why bigger is better, according to wind experts, is that longer turbine blades capture the wind more efficiently, and taller towers allow for longer blades. The power of a turbine is proportional to its size “According to Christopher Niezrecki, a professor of mechanical engineering and head of the University of Massachusetts Lowell’s Center for Wind Energy, “swept area” refers to the circular area covered by the blades’ rotation. And, as Niezrecki shows, this relationship is not linear: if blade length doubles, a system can produce four times as much energy. He points out that larger turbines have a lower efficiency “The wind speed at which they can begin generating energy is known as the “cut-in” speed.
Loth’s team hopes to create a 50-megawatt system with blades that are 200 meters long, which is substantially larger than current wind turbines. The researchers predict that if they succeed, the turbine will be ten times more powerful than current equipment. However, the researchers are not simply enlarging existing designs; they are radically altering the turbine construction. The ultralarge machine will have two blades rather than the typical three, reducing the structure’s weight and slashing costs. Although lowering the number of blades would normally make a turbine less efficient, Loth claims that his team’s sophisticated aerodynamic design compensates for those losses.
According to Loth, the team also envisions these massive structures standing at least 80 kilometers offshore, where winds are greater and people on land cannot see or hear them. But when powerful storms hit such locationsfor example, off the east coast of the United States in the Atlantic Oceanteam Loth’s was faced with the challenge of designing something large while remaining relatively lightweight and sturdy in the face of hurricanes. The researchers used one of nature’s own design ideas to solve the problem: palm plants. “Palm trees are very tall, but physically they are very light, and the trunk can bow if the wind blows hard,” Loth notes. “We’re attempting to use the same notion by designing our wind turbines to be flexible, bending and adapting to the flow.”
The two blades are situated downwind of the turbine’s tower in the team’s design, rather than upwind as they are on standard turbines. Like a palm tree, the blades change shape in response to the direction of the wind. “You don’t need to construct the blades as heavy or sturdy when they bend back at a downwind angle, so you can use less material,” Loth explains. This design also reduces the risk of a spinning blade being bent toward its tower by heavy winds, potentially bringing the entire structure down. “At high speeds, the blades will adjust and begin to fold in, reducing the dynamic stresses on them,” Loth explains. “In non-operational conditions, we’d like our turbines to be able to handle winds of more than 253 kilometers per hour.” The system would shut down at 80 to 95 kilometers per hour, and the blades would bend away from the wind to survive powerful gusts, according to Loth.
The 500-meter turbine still confronts difficulties, and there are valid reasons why no one has attempted to build one of this size: “How do you produce blades that are 200 meters long? What’s the best way to put them together? How do you build such a tall structure? Cranes can only reach a certain height. “There are additional challenges with offshore wind,” Niezrecki adds. The team’s idea features a segmented blade that could be constructed on-site from sections, but Niezrecki points out that the wind industry has yet to find out how to segment blades. “He says, “There are a lot of research questions that need to be answered.” “It carries a significant risk, but it also has the potential for a great payout. Those issues, in my opinion, are not insurmountable.” Hall also wonders if such a huge turbine is the best size. “We’ve discovered that bigger is better. The question is, how much larger will it be? He continues, “We need to find that sweet spot.” “This project will teach us a great deal.”
Loth and his team have yet to test a prototype; they are now designing the turbine’s structure and control system, and this summer they will build a model that is about two meters in diameter, much smaller than the actual thing. They intend to build a larger version with two 20-meter-long blades that will generate less than a kilowatt of power and will be tested in Colorado next summer. Loth himself is unsure whether his team’s massive turbine will become a reality, but he believes it is worth a shot. “There are no promises that this will succeed because it is a fairly novel concept,” he explains. “But if it succeeds, offshore wind energy will be transformed.”
What is the height of a wind turbine’s base?
The hub height of a wind turbine is the distance from the ground to the center of the rotor. Since 19981999, the hub height of utility-scale land-based wind turbines has climbed by 59%, to around 90 meters (295 ft) in 2020. That’s around the same height as the Statue of Liberty! In the United States, the average hub height for offshore turbines is expected to rise even higher, from 100 meters (330 feet) in 2016 to around 150 meters (500 feet) in 2035, or roughly the same height as the Washington Monument.
How big are the feet of a wind turbine?
In any case, the goal is to keep making turbines bigger and bigger. When it comes to land-based (onshore) turbines, the process runs into a number of non-technical roadblocks, including transportation and infrastructure bottlenecks, land-use considerations, concerns about views, huge birds, and shadows, among other things.
However, wind power is increasingly moving out to sea, particularly in Europe. And out in the middle of the ocean, where land is barely visible, the only restriction to size is engineering. As a result, offshore turbines are now growing at a higher rate than onshore turbines over the last decade.
In March of this year, a clear example of this pattern emerged (when I first published this story). GE Renewable Energy said that it will invest $400 million in the development of a new monster turbine called the Haliade-X, which will be the world’s biggest, tallest, and most powerful turbine (at least until the next big announcement).
It’s a remarkable engineering achievement, but the significance of increasing turbine size goes far beyond that. Turbines that are larger gather more energy and do so more consistently; the larger they are, the less variable and predictable they become, and the easier they are to integrate into the grid. On wholesale energy markets, wind is already outcompeting traditional sources. It won’t even be a competition after a few more generations of expansion.
What wind turbines are getting up to
Let’s start with some comparisons to get a sense of the size of this new GE turbine.
To gather the most up-to-date information on wind turbine sizes, I called Ben Hoen, a research scientist at Lawrence Berkeley National Laboratory. (He emphasizes that these are early data; LBNL will release a report on this in a few months, but he does not expect the figures to change significantly, if at all.)
In 2017, the average overall height (from base to tip) of an onshore US turbine was 142 meters, according to Hoen (466 feet). The median turbine height was at 152 meters (499 feet). In fact, according to Hoen, the median is getting close to the maximum. In other words, onshore wind turbines in the United States appear to be gradually approaching that height. Why? Because if you build higher than 499 feet, the FAA demands certain more steps in their clearance process, which most developers don’t seem to think is worth the trouble.
The Hancock Wind project in Hancock County, Maine, houses the world’s tallest onshore wind turbines. Those are around 574 feet tall Vestas V117-3.3s, if you must know.
So that’s all for the onshore. What about a trip to the islands? So far, the US has only one operational offshore wind farm, the Block Island Wind Farm off the coast of Rhode Island. Its turbines reach a height of about 590 feet.
How does the Haliade-X stack up against all of that? It will be 853 feet tall, according to GE.
That would be the world’s tallest wind turbine, as far as I’m aware. The previous record holder, as far as I can gather from searching (as I said, these things change frequently), is an 809-foot onshore turbine in Germany.
Bigger turbines mean more power, more often
However, height isn’t the only factor to consider. There are a few other accolades for the Haliade-X.
The whole sweep of the turbine’s blades is measured by the rotor diameter (the diameter of the circle they define). When all other factors are equal, a larger rotor diameter means the turbine can capture more wind.
According to Hoen, the average rotor diameter of US wind turbines was 367 feet in 2017. The rotor diameter of the Haliade-X will be 722 feet, which is almost double the average. The blades will be massive, measuring 351 feet in length each, longer than a football field and longer than any other offshore blade to date, according to GE.
The Haliade-X will have a very high capacity factor because to its huge rotor diameter, steady offshore wind, and 12MW turbine (onshore averages approximately 3MW; offshore around 6MW).
The following excerpt from the 2016 Wind Technologies Market Report by the Department of Energy illustrates how wind capacity factors have changed over time: “The average 2016 capacity factor for projects completed in 2014 and 2015 was 42.5 percent, compared to 32.1 percent for projects completed between 2004 and 2011, and just 25.4 percent for projects completed between 1998 and 2001.”
In 2016, the nuclear fleet in the United States had an average capacity factor of roughly 92 percent. (Nuclear is only economically viable in today’s markets when it is used as a baseload generator.) Coal and natural gas accounted for 55 and 56 percent of the total. (Natural gas is so cheap because it is routinely ramped up and down to match demand swings.) Coal used to be close to 80 percent, but it is becoming increasingly uneconomic to operate coal plants.)
So, in the United States today, wind energy accounts for 42.5 percent of total energy consumption, whereas natural gas accounts for 56 percent. According to GE, the Haliade-X would have a capacity factor of 63 percent. Though it wouldn’t be the highest in the world, the floating offshore turbines in the Hywind Scotland project just surpassed 65 percent.
When you add it all together, each Haliade-X will produce roughly 67GWh annually at a “typical German North Sea location,” according to GE, “enough clean power for up to 16,000 people per turbine, and up to 1 million European households in a 750 MW windfarm configuration.” (It goes without saying that the number would be lower for energy-sipping American households.) That’s it “It generates 45 percent more electricity than any other offshore wind turbine on the market today,” the business claims.
In Rotterdam, the Netherlands, the first Haliade-X is now being built. In April, GE said that it would start producing electricity later this year.
Bigger turbines that run more often are going to crush all competitors
This 2015 piece by energy researcher Ramez Naam on the ultimate potential of wind power is one of my favorites. “Even at today’s price per kwh, wind at 60% capacity factor would be considerably more useful than it is currently, with fewer constraints to how much of it we might utilize,” he wrote.
- The more volatile a source is, the more backup is required to solidify and ensure its reliability. (At the moment, backup is mostly provided by natural gas plants, however batteries are becoming more common.) Higher capacity factors lower backup costs by making wind less variable and more reliable.
- Renewable energy that is variable (sun and wind) has a tendency to “eat its own lunch.” The next increment of capacity added lowers the clearing price for all the other increments since it all produces energy at the same time (when the sun shines or the wind blows). The lower the price, the more energy comes online at once. A turbine with a 60 percent capacity factor blunts and reduces this price-suppressing effect by spreading its energy out over a longer period about twice the 32 percent of 2011-vintage turbines.
Although a capacity factor of 60% or above isn’t precisely “baseload,” it does appear to be less variable. Even if the price of wind energy remained constant, turbines like the Haliade-X would be more valuable.
It won’t stay the same, though; it’s down 65 percent since 2009. According to a recent NREL analysis, advancements in wind power technology (including larger turbines) could reduce it by another 50% by 2030. (University of Virginia researchers are working on a design for an offshore turbine that will be 1,640 feet taller than the Empire State Building.)
Assume that by 2025, new wind turbines in the United States have an average hub height of 460 feet, which is substantially in line with current forecasts. According to NREL research, such turbines may have capacity factors of 60 percent or higher across more than 750,000 square miles of US land and 50 percent or higher across 1.16 million square miles.
With expected developments in wind technology, that much wind, at that capacity factor, will create power cheap enough to demolish all competitors. And the year 2025 isn’t all that far away.
How much concrete do I need for the foundation of a wind turbine?
Democrats envision a civilization powered entirely by wind and solar farms, as well as large batteries. Realizing this dream would necessitate the world’s largest mining expansion, as well as massive amounts of waste.
“The term “renewable energy” is misleading. Nonrenewable resources are used to construct wind and solar machines and batteries. They also wear out. Decommissioning old equipment generates millions of tons of garbage. According to the International Renewable Energy Agency, solar goals set for 2050 in accordance with the Paris Accords will result in old-panel disposal accounting for more than double the current worldwide plastic waste volume. Consider the following depressing figures:
A single battery for an electric vehicle weights around 1,000 pounds. To make one, more than 500,000 pounds of raw materials must be dug up, moved, and processed somewhere on the earth. What’s the alternative? To deliver the same amount of vehicle miles over the battery’s seven-year life, use gasoline and extract one-tenth as much overall weight.
When electricity is generated by wind or solar machines, each unit of energy produced, or mile traveled, necessitates significantly more materials and area than when it is generated by fossil fuels. That physical reality is plain to see: A wind or solar farm that stretches to the horizon can be substituted by a few gas-fired turbines the size of a tractor-trailer.
A wind turbine requires 900 tons of steel, 2,500 tons of concrete, and 45 tons of non-recyclable plastic to construct. Solar energy necessitates much more cement, steel, and glass, as well as other metals. According to the International Energy Agency, global silver and indium mining will increase by 250 percent and 1,200 percent over the next two decades, respectively, to produce the materials needed to build the required number of solar panels. To fulfill the Paris green objectives, global demand for rare-earth elements will climb 300 percent to 1,000 percent by 2050. Scarce-earth elements aren’t rare, but they’re rarely mined in America. Demand for cobalt and lithium will more than 20-fold if electric vehicles replace conventional cars. This does not include backup batteries for wind and solar grids.
A study commissioned by the Dutch government last year indicated that the Netherlands’ green goals would absorb a significant portion of world minerals on their own. “With today’s technologies and annual metal production, exponential increase in renewable energy production capacity is not achievable,” it concluded.
Mines in Europe and the United States are unlikely to meet the demand for minerals. Instead, much of the mining will be done in countries with harsh labor laws. 70% of the world’s raw cobalt is produced in the Democratic Republic of the Congo, while China controls 90% of cobalt refining. The Institute for a Sustainable Future in Sydney warns that a global “gold rush” for minerals could lead to miners entering “certain distant wilderness areas that have retained high biodiversity because they haven’t been disturbed yet.”
To manufacture enough wind turbines to supply half of the world’s electricity, almost two billion tons of coal and two billion barrels of oil would be needed to make the concrete and steel, as well as two billion barrels of oil to make the composite blades.
What is the diameter of a wind turbine’s base?
Many people visualize little machines behind someone’s house when they think about wind turbines. According to National Wind Watch, industrial wind turbines are gigantic pieces of technology with blades that can easily stretch hundreds of feet.
Wind turbines generate energy at a lower cost due to economies of scale, therefore larger turbines can generate more electricity.
Components for wind turbines are frequently carried by road.
Turbines are secured in steel and rebar platforms that easily exceed 1,000 tons in weight and rest 6 to 30 feet in the ground once they are built. Turbines must then be outfitted with lights so that they can be seen. On average, per megawatt, they take up around 50 acres of land.
Wind turbines generate energy at a lower cost due to economies of scale, therefore larger turbines can generate more electricity. Furthermore, larger turbines are more efficient and therefore better suited for use offshore. Smaller turbines, on the other hand, are quicker to construct and produce less energy fluctuation.
Wind turbines, regardless of their size, are a striking addition to the environment. The rotor diameter of a wind turbine with a 600-kW generator is typically around 144 feet. You may acquire four times the power by doubling the diameter. Machines are frequently modified to cater for local wind conditions. Many extant models reach heights of over 400 feet, with extra-long towers and larger and longer blades.
Vestas, Gamesa, and General Electric are the most prevalent turbine manufacturers in the United States, however some older facilities still use NEG Micon and Zond turbines. The GE 1.5-megawatt model, for example, has 116-foot blades on a 212-foot tower, but the Vestas V90 has 148-foot blades on a 262-foot tower. The GE 1.5-megawatt variant is almost 164 tons in weight, with the tower alone weighing roughly 71 tons. The Vestas V90 has a total weight of around 267 tons.
Continue reading for a list of the most common wind turbines now in production or set to start soon, as well as their sizes.
In feet, how tall is a wind turbine tower?
Industrial wind turbines are significantly larger than those found in a playground or behind a home.
For example, the widely used GE 1.5-megawatt model has 116-foot blades atop a 212-foot tower, for a total height of 328 feet. The blades cover just under an acre of vertical airspace.
On a 262-foot tower, the 1.8-megawatt Vestas V90 from Denmark has 148-foot blades (sweeping more than 1.5 acres) and a total height of 410 feet.
The 2-megawatt Gamesa G87 from Spain, with 143-ft blades (just under 1.5 acres) on a 256-ft tower, totaling 399 feet, is another model that is becoming increasingly popular in the United States.
What is the steel content of a wind turbine foundation?
Steel alone accounts for 150 metric tons for reinforced concrete foundations, 250 metric tons for rotor hubs and nacelles (which house the gearbox and generator), and 500 metric tons for the towers in a 5-megawatt turbine.
What is the weight of a wind turbine blade?
A typical rotor blade for a 0.75-MW turbine has a length of 80 ft to 85 ft (24m to 25m) and weighs around 5,200 lb/2,360 kg, according to some of the metrics provided for this market assessment. Blades are expected to cost around $55,000 each at this size, or $165,000 for a three-blade set. The amount of reinforcing grows in a logarithmic progression as the blades grow larger. Typical blades for a 1.5-MW turbine should be 110 ft to 124 ft (34m to 38m) long, weigh 11,500 lb/5,216 kg, and cost between $100,000 and $125,000 each. A turbine’s blades are around 155 ft/47m long, weigh about 27,000 lb/12,474 kg, and cost between $250,000 and $300,000 apiece when rated at 3.0 MW.
Using the aforementioned guidelines, wind turbine manufacturers produced around 441 million lb or slightly more than 200,000 metric tonnes of final blade structures in 2007. This makes wind turbine blade manufacturing one of the world’s largest single applications of engineered composites. Surprisingly, the astonishing volume in 2007 is about 38 percent more than in 2006 and nearly double that of 2005.
- 182 million lb Thermoset resins (mainly epoxy and vinyl ester) (82,550 metric tonnes)
The value of the blade market is sometimes calculated as a percentage of the market for turbines. Blades are thought to account for 15 to 20% of the total cost of a wind turbine. During 2007, the market for entire wind turbine systems was estimated to be somewhat more than $26 billion. Based on this, the composite blade market is anticipated to be worth between $3.9 and $5.2 billion. We believe that a more precise estimate of the composite blade market is $4.3 billion, based on current material prices and our estimates of production and overhead expenses (as previously mentioned). This represents a 43 percent increase over expected 2006 blade sales and a 114 percent increase over 2005. Blade producers should ship more than $5.9 billion worth of gear this year, based on predicted industry growth. This is a 38 percent increase in monetary value, while new installed capacity (MW) is predicted to increase by 26 percent. Although rising raw material prices (as petroleum and other chemical feedstocks become more expensive) can account for some of the disproportionate growth in blade value, product availability/shortages and the trend toward larger turbines with more expensive rotor systems are more relevant considerations.