David Savastano, Contributing Editor10.11.21
Renewable energy is becoming increasingly important in our lives. Each of the main types of renewable energy – solar, wind, water and others – have their own unique requirements. In the case of wind power, wind turbines have very specific coating needs, as the turbines need to be protected from harsh environments.
As one of the world’s leading manufacturers and suppliers of protective coatings, Hempel offers corrosion protection to structures in some of the harshest conditions on the planet.
“We have been a partner to the wind energy industry since the very beginning and our coatings protect many of the world’s windfarms,” David Heal, global head of renewable energy & performance OEM segments at Hempel, noted.
Heal pointed out that commercial wind power was pioneered in Denmark in the 1970s and 1980s, and Hempel has been part of its development from the very start.
“With our headquarters and main R&D center in Copenhagen, we have been in a unique position among coating suppliers, able to immerse ourselves in the wind segment, to understand the needs of our customers and to collaborate with them to develop solutions tailored to the very specific requirements of the industry,” added Heal.
“This partnership approach continues today and, as the wind industry evolves, we evolve too,” he noted. “We continue to work closely with the key industry players, collaborating on projects to improve efficiency, reduce environmental impact and grow the segment globally.”
Heal estimates that Hempel’s protective coatings are used on approximately 50% of wind turbines across the globe. There’s more than the blades that need coatings though – Hempel provides coating solutions for the entire wind turbine, including the towers, blades, foundations and nacelles. And there’s more.
“Asset protection in the wind energy industry isn’t just about the turbine,” Heal observed. “A windfarm is very complex, with a wide range of structures, including substations, buildings and service infrastructure, as well as port equipment and vessels for offshore installations. We provide coatings for all these assets.”
The wind industry is rapidly growing in size and importance, which Heal noted makes it a very dynamic environment for coatings development.
“Wind turbine towers, for example, have traditionally been made of steel or concrete,” he added. “However, they are increasingly made from different substrates, including composites.
Our experience in other coatings segments, such as the yacht industry, is invaluable in developing coating solutions to protect these substrates from the harsh environment of a
working windfarm.
“The industry is also increasingly global,” Heal continued. “Windfarm projects are often multinational, with different elements constructed in different parts of the world. To ensure consistency in coatings supply and performance, as well as adherence to relevant standards, these projects require a global coatings supplier that understands the complexities and has globally coordinated local teams that can provide products, services and advice, as needed. With our experience and global presence, Hempel is uniquely placed to meet these needs.”
Key Aspects for Choosing Coatings
Not surprisingly, durability is the single biggest requirement that customers are looking for in a coating, as windfarms are located in hard-to-access locations, often out at sea or in remote inland areas. The greater the durability, the better.
“Taking a turbine out of action for repair is extremely costly,” Heal noted. “Therefore, structures in the wind industry are coated to ensure protection against corrosion for the longest possible time. Depending on the environment, a wind turbine is expected to last 25 years – and the coating system should require little or no maintenance during that time.
Discussions are now underway to increase this lifetime to 35 years for offshore installations.”
Heal observed that there is more to “durability” in the wind industry than meets the eye. Downtime is costly, and efficiency is key.
“The real requirement for wind turbine manufacturers, operators and owners is to find ever-more efficient solutions that bring down the total cost of wind energy per kilowatt hour to become as economically competitive as other energy industries, or more so,” he added. “This means wind turbine manufacturers, operators and owners must increase efficiency across the entire value chain.
“Durability, therefore, is about extending wind turbine lifetimes and reducing or eliminating maintenance – both of which improve return on investment. At the same time, efficiency gains during application – thanks to the use of lower DFTs, fast-drying systems and easier-to-apply, more tolerant coatings – increase productivity and reduce the production cost per unit. This all brings down the total cost of wind energy per kilowatt hour.”
Add to this sustainability requirements and standards such as ISO 12944, and choosing the correct coating can be complex.
“The challenges for onshore and offshore wind turbines also differ, and require specially formulated coating solutions,” Heal said. This is why it’s critical that OEMs work closely with their coatings suppliers to ensure that the most suitable coatings are applied at the point of manufacture. With the right coating applied, application costs and VOC emissions can be reduced during production, and protection against corrosive environments can be provided that will last for the lifetime of the asset.”
Heal gave two examples of how the right choice of coatings can make a huge difference for wind turbines.
“A recent inspection was carried out on the Thunoe Knob offshore windfarm outside Aarhus in Denmark, which was coated by Hempel in 1995,” said Heal. “One of the world’s longest serving installations, Thunoe Knob is testament to the importance of using the correct coating system. Four of the 10 turbines were chosen at random and evaluated through visual examination, photographic documentation and dry film measurement. Despite being more than 20 years old at the time, the inspection found that both the interior and exterior coating systems were in good condition and could be expected to remain so for at least another 10 years, demonstrating a practical coating lifetime of more than 30 years.
“In the same year, the Horns Rev 1 windfarm, located in the North Sea near the Danish city of Esbjerg, was also inspected. In this hostile location, the environment was classified under the ISO 12944-Part 2 standard as C5 M – a very highly corrosive marine environment with high salinity. Once again four wind turbines were chosen at random and evaluated.
The exterior and interior coated surfaces were found to be in prime condition and, from the overall results, it was estimated that the coating system would have a service life of at least 27 years.
“Both these examples demonstrate that the correct coating system can extend a windfarm’s service life and reduce maintenance, which lowers the overall cost of energy production over the windfarm’s entire lifetime,” Heal concluded.
Hempel Products for Wind Turbines
With all of the variety needed for wind turbines, Hempel has bespoke products for the wind industry, developed in partnership with leading businesses throughout the wind supply chain.
These include 4774D, a two-coat wind tower protection system that dries up to 30 percent faster than equivalent three-coat systems. This helps eliminate production bottlenecks, increases throughput and reduces drying hall costs. The two-coat system also means lower VOC emissions and less paint and waste, which all contributes to reducing the overall cost of wind tower production.
Offshore wind foundations hold a different challenge with extremely aggressive conditions in the splash zone (the area that cycles between being submerged and atmospherically exposed due to tides, waves and currents). Heal reported that Hampel’s products for these areas meet the most rigorous NORSOK M501 certification requirements while delivering key attributes that are important to applicators and owners alike.
“Hempadur 35620 is our solvent-free epoxy system, which provides outstanding corrosion protection but also offers environmental benefits as it is 100% volume solids with almost no volatile organic compounds (VOC),” Heal added. “Hempadur Multi-Strength 45703/45753 is a high solids epoxy system which also provides outstanding corrosion protection and has been applied on over one million square metres of offshore structures over the last 20 years. We are continuing to develop new products for all of the wind segments to increase productivity, reduce environmental impact and maximise longevity.”
As one of the world’s leading manufacturers and suppliers of protective coatings, Hempel offers corrosion protection to structures in some of the harshest conditions on the planet.
“We have been a partner to the wind energy industry since the very beginning and our coatings protect many of the world’s windfarms,” David Heal, global head of renewable energy & performance OEM segments at Hempel, noted.
Heal pointed out that commercial wind power was pioneered in Denmark in the 1970s and 1980s, and Hempel has been part of its development from the very start.
“With our headquarters and main R&D center in Copenhagen, we have been in a unique position among coating suppliers, able to immerse ourselves in the wind segment, to understand the needs of our customers and to collaborate with them to develop solutions tailored to the very specific requirements of the industry,” added Heal.
“This partnership approach continues today and, as the wind industry evolves, we evolve too,” he noted. “We continue to work closely with the key industry players, collaborating on projects to improve efficiency, reduce environmental impact and grow the segment globally.”
Heal estimates that Hempel’s protective coatings are used on approximately 50% of wind turbines across the globe. There’s more than the blades that need coatings though – Hempel provides coating solutions for the entire wind turbine, including the towers, blades, foundations and nacelles. And there’s more.
“Asset protection in the wind energy industry isn’t just about the turbine,” Heal observed. “A windfarm is very complex, with a wide range of structures, including substations, buildings and service infrastructure, as well as port equipment and vessels for offshore installations. We provide coatings for all these assets.”
The wind industry is rapidly growing in size and importance, which Heal noted makes it a very dynamic environment for coatings development.
“Wind turbine towers, for example, have traditionally been made of steel or concrete,” he added. “However, they are increasingly made from different substrates, including composites.
Our experience in other coatings segments, such as the yacht industry, is invaluable in developing coating solutions to protect these substrates from the harsh environment of a
working windfarm.
“The industry is also increasingly global,” Heal continued. “Windfarm projects are often multinational, with different elements constructed in different parts of the world. To ensure consistency in coatings supply and performance, as well as adherence to relevant standards, these projects require a global coatings supplier that understands the complexities and has globally coordinated local teams that can provide products, services and advice, as needed. With our experience and global presence, Hempel is uniquely placed to meet these needs.”
Key Aspects for Choosing Coatings
Not surprisingly, durability is the single biggest requirement that customers are looking for in a coating, as windfarms are located in hard-to-access locations, often out at sea or in remote inland areas. The greater the durability, the better.
“Taking a turbine out of action for repair is extremely costly,” Heal noted. “Therefore, structures in the wind industry are coated to ensure protection against corrosion for the longest possible time. Depending on the environment, a wind turbine is expected to last 25 years – and the coating system should require little or no maintenance during that time.
Discussions are now underway to increase this lifetime to 35 years for offshore installations.”
Heal observed that there is more to “durability” in the wind industry than meets the eye. Downtime is costly, and efficiency is key.
“The real requirement for wind turbine manufacturers, operators and owners is to find ever-more efficient solutions that bring down the total cost of wind energy per kilowatt hour to become as economically competitive as other energy industries, or more so,” he added. “This means wind turbine manufacturers, operators and owners must increase efficiency across the entire value chain.
“Durability, therefore, is about extending wind turbine lifetimes and reducing or eliminating maintenance – both of which improve return on investment. At the same time, efficiency gains during application – thanks to the use of lower DFTs, fast-drying systems and easier-to-apply, more tolerant coatings – increase productivity and reduce the production cost per unit. This all brings down the total cost of wind energy per kilowatt hour.”
Add to this sustainability requirements and standards such as ISO 12944, and choosing the correct coating can be complex.
“The challenges for onshore and offshore wind turbines also differ, and require specially formulated coating solutions,” Heal said. This is why it’s critical that OEMs work closely with their coatings suppliers to ensure that the most suitable coatings are applied at the point of manufacture. With the right coating applied, application costs and VOC emissions can be reduced during production, and protection against corrosive environments can be provided that will last for the lifetime of the asset.”
Heal gave two examples of how the right choice of coatings can make a huge difference for wind turbines.
“A recent inspection was carried out on the Thunoe Knob offshore windfarm outside Aarhus in Denmark, which was coated by Hempel in 1995,” said Heal. “One of the world’s longest serving installations, Thunoe Knob is testament to the importance of using the correct coating system. Four of the 10 turbines were chosen at random and evaluated through visual examination, photographic documentation and dry film measurement. Despite being more than 20 years old at the time, the inspection found that both the interior and exterior coating systems were in good condition and could be expected to remain so for at least another 10 years, demonstrating a practical coating lifetime of more than 30 years.
“In the same year, the Horns Rev 1 windfarm, located in the North Sea near the Danish city of Esbjerg, was also inspected. In this hostile location, the environment was classified under the ISO 12944-Part 2 standard as C5 M – a very highly corrosive marine environment with high salinity. Once again four wind turbines were chosen at random and evaluated.
The exterior and interior coated surfaces were found to be in prime condition and, from the overall results, it was estimated that the coating system would have a service life of at least 27 years.
“Both these examples demonstrate that the correct coating system can extend a windfarm’s service life and reduce maintenance, which lowers the overall cost of energy production over the windfarm’s entire lifetime,” Heal concluded.
Hempel Products for Wind Turbines
With all of the variety needed for wind turbines, Hempel has bespoke products for the wind industry, developed in partnership with leading businesses throughout the wind supply chain.
These include 4774D, a two-coat wind tower protection system that dries up to 30 percent faster than equivalent three-coat systems. This helps eliminate production bottlenecks, increases throughput and reduces drying hall costs. The two-coat system also means lower VOC emissions and less paint and waste, which all contributes to reducing the overall cost of wind tower production.
Offshore wind foundations hold a different challenge with extremely aggressive conditions in the splash zone (the area that cycles between being submerged and atmospherically exposed due to tides, waves and currents). Heal reported that Hampel’s products for these areas meet the most rigorous NORSOK M501 certification requirements while delivering key attributes that are important to applicators and owners alike.
“Hempadur 35620 is our solvent-free epoxy system, which provides outstanding corrosion protection but also offers environmental benefits as it is 100% volume solids with almost no volatile organic compounds (VOC),” Heal added. “Hempadur Multi-Strength 45703/45753 is a high solids epoxy system which also provides outstanding corrosion protection and has been applied on over one million square metres of offshore structures over the last 20 years. We are continuing to develop new products for all of the wind segments to increase productivity, reduce environmental impact and maximise longevity.”
