With a blade diameter spanning more than two football fields, GE Renewables’ Haliade-X turbines are already the largest and most powerful in the world, capable of generating up to 14 MW of energy. The ability to 3D print the concrete base of the turbine on site, for direct transport to the final location at sea, will allow even larger systems to be built and deployed.
This approach is expected to allow for the production of much higher wind turbines because turbine producers will not be hampered by transportation limitations–today, the width of the base cannot exceed 4.5 meters for transportation reasons, which limits the height of the turbine. By increasing the height, the power generation per turbine can also be increased substantially: for example, a 5 MW turbine measuring 80 meters generates about 15.1 GWh per year. The same 160 meter turbine would generate 20.2 GWh per year, an increase of 33%. How this scale should become even bigger, with new turbines reaching heights of 260 meters and even more.
The first prototype of the Heliade X turbine went into operation at the Port of Rotterdam, in the Netherlands, just over a year ago. It became the first wind turbine to produce 288 megawatt hours of energy in 24 hours. That may have been enough to supply 30,000 homes in that area.
The new offshore turbine Haliade-X has a capacity of 14 MW, 13 MW or 12 MW, rotor of 220 meters, blade of 107 meters and digital resources. Not only is it the most powerful wind turbine in the world, but it also has a capacity factor of 60-64% above the industry standard. The capacity factor compares how much energy was generated with the maximum that could have been produced in continuous operation at full power over a specific period of time. Each incremental point in the capacity factor represents about $ 7 million in revenue for the turbine owner over the life of a wind farm.
In October, the machine, which is also the most powerful offshore wind turbine in operation today, produced 312 megawatt-hours of energy in a single 24-hour period. GE Renewable Energy engineers spent the past year collecting data on the Rotterdam prototype to obtain a complete “type certificate” for the machine – verification by an independent body, DNV GL, that the new turbine will operate safely, reliably and according to design specifications. DNV GL granted this certification to the offshore Haliade-X 12 MW.
“This is an important milestone for us, as it gives our customers the ability to obtain financing when purchasing Haliade-X,” said Vincent Schellings, who leads the turbine development for GE Renewable Energy. “Our ongoing goal is to provide them with the technology they need to drive the global growth of offshore wind energy as it becomes an increasingly affordable and reliable renewable energy source.” It’s a good deal to be in: The International Energy Agency has projected the cumulative investment in offshore wind energy at $ 1 trillion by 2040.
The type certification came shortly after a constituent part of the turbine – its 107 meter long blade, which exceeds the length of a football field – received its own component certification. The certification process for the Haliade-X 12 MW involved separate testing of its blades, at facilities in the United States and the United Kingdom, and testing involving the prototype in Rotterdam.
GE designed Haliade-X to generate 12 megawatts, but tests in Rotterdam revealed that it could surpass its original objectives, in the order of 13 megawatts. The new type certification specifically involves 12 MW; testing of the Rotterdam prototype at 13 MW is underway, with separate certification scheduled for the first half of 2021.
Next after that milestone? Installation. GE Renewable Energy signed the first contract for Haliade-X 13 MW, agreeing to supply 190 of the machines to Dogger Bank A and Dogger Bank B, the first two phases of what is expected to be the largest offshore wind farm in the world, located in the North Sea, about 130 kilometers off the coast of Yorkshire, England. Scheduled for completion in 2026, the farm was designed to be able to generate 3.6 gigawatts of electricity – enough to supply 4.5 million homes in the UK.
The challenges associated with producing larger wind turbines do not stop at the base. Blades over 100 meters long must also be produced as a single piece – they cannot be assembled in multiple sections – and the strength of fiberglass-reinforced plastics is reaching its physical limits in the face of increasing wind forces .
Today, blades are produced using extremely expensive advanced molds, which are not only extremely large, but also need to be very complex to allow effective cooling and curing of the fiberglass-reinforced blade. In the future, large format composite 3D printing technologies may allow for more economical production of these blade molds and – perhaps even direct production of carbon fiber reinforced blades over 100 meters in length. Clearly, these features are not available today, but companies like Ingersoll and Themrwood have demonstrated that there is no inherent limit to the size of large format composite 3D printing systems.
In 2018, the Office of Wind Energy Technologies and the Office of Advanced Manufacturing of the U.S. Department of Energy partnered with another large format composite 3D printing company, Cincinnati Inc, to apply additive manufacturing to the production of large blade molds of wind turbines.
3D printing was seen as a very attractive option for large products, such as wind turbine blades, which require a lot of labor, mainly made by hand to deposit large amounts of composite material, making the molds quite expensive and timely to make.
In the wind power industry, the use of additive manufacturing to produce customized blades directly from CAD can also mean tower-optimized wind turbine blades in a wind farm. This means that the blades of each turbine can one day be optimized for individual location, wind and turbulence patterns at each farm location and on each different farm. Additive manufacturing is the technology that makes all of this possible with a lower price and shorter delivery times.
It won’t happen anytime soon, so don’t hold your breath. AM still presents significant limits in terms of density and quality of the final material, process repeatability and costs. Not to mention that technologies to produce objects as large as a single component have not yet been developed. However, if the turbines get bigger and bigger (and they will), their production processes will necessarily have to include 3D printing.
