“Lubrication has an impact on the bottom line and an operator’s capacity to produce energy profitably,” explained Travil Lail, ExxonMobil’s Americas Industrial Marketing Advisor.
Oil drainage intervals, he noted, can vary greatly between operators and are mostly determined by the location of a turbine and the number of hours it has been in operation. He claims that a totally synthetic wind turbine lubricant, such as ExxonMobil’s, can lengthen the time between oil changes by up to three years. He said, “We have documented documentation of up to 40,000 hours.”
“The remoteness of wind turbines is a major barrier,” said Felix Guerzoni, a Shell Global Solutions product application specialist. A wind turbine may be inspected and maintained once every six months at most, with the chance to sample gearbox oil for testing or relubricate or grease spots.
Shell Lubricants unveiled a line of lubricants for wind turbine hydraulic systems, blades, gearboxes, and yaw and pitch drives in May.
Gearbox micropitting, which is caused by factors such as case hardening and the surface roughness of the gear teeth, is a key source of reliability concern. Micropitting is less likely if the surface roughness is kept to a minimum, he says. Specialized gear oils can help lower the risk of mircopitting even more. Anti-foaming is a crucial gear oil quality due to the size of the gearbox and the possibility of air entrainment in the system. Excessive foam can cause a lubricant’s viscosity to drop, reducing its capacity to protect against micropitting and bearing failure.
Guerzoni said there is a trend for the recommended amount of filtration to drop from 10 microns to 3 microns to assist prevent bearing failure. This improves the purity of the oil and extends the life of the bearings.
Shell offers a variety of lubricants, including:
- The hydraulic fluid Tellus Arctic 32 is used in extreme-climate wind turbines. Svendborg Brakes and wind turbine manufacturers such as GE Wind, Voith Wind, Vestas, Dongfang Wind Turbines, Sinovel, RePower, Nordex, and DHI promote or list the product.
- At temperatures as low as -55oC, Shell Rhodina BBZ is designed to prevent blade bearings from fretting corrosion, moisture contamination, and false brineling.
- Shell Omala HD 320 synthetic gear oil protects against micropitting and bearing wear, two common failure mechanisms.
Shell Lubricants also supplies Shell Tivela S 150 and 320 synthetic gear oils for yaw and pitch drives, as well as Shell Albida EMS 2 electric motor bearing synthetic grease, Shell Stamina HDS main bearing grease, and Shell Malleus GL & OGH top quality open gear grease.
Shell stated that while cost is an issue whenever synthetic oil is discussed, its benefits become more obvious when lifetime running and maintenance expenses are considered. One significant benefit is that a synthetic’s extended life minimizes the number of times maintenance employees must climb the turbine tower. Synthetics can also lower the likelihood of a gearbox requiring repair or replacement owing to lubrication concerns. Synthetics may also provide an advantage over conventional fluids, which have limited fluidity at low temperatures, given the wide temperature range that wind turbines must function in.
Another excellent practice, according to Lail, is to have a continuous oil monitoring program in place. A service like this can keep track of things like viscosity, metal wear, thermal and oxidative stability, and water contamination, among other things.
“Water contamination affects the life of the bearings and the oil filter for many clients,” he stated.
These things can have a big impact on operations.
He claims that the industry has placed a higher emphasis on oil purity and particulate measurement in the last year. Despite the fact that turbine makers need testing as part of their warranty requirements and lubricant suppliers guarantee their oil for a specific cleanliness, he added there are currently no industry-wide standards for particulate counting. Dilutants used to pretreat an oil, he claims, can assist prevent water intrusion. Furthermore, ultrasonic treatment can eliminate oxygen, which has a significant impact on cleanliness.
In general, a competent oil analysis program, according to Lail, can provide insights into equipment health and assist operators in making condition-based maintenance decisions rather than calendar-based maintenance decisions.
Dow Chemical, a new player in the wind turbine lubricant business, launched a polyalkalene glycol lubricant in May after 18 months of product testing. Initial sales will be concentrated in Europe and Asia, with North America following. Instead of a variety of viscosities, the Dow product only offers one: 320. According to Brian Goldstein, worldwide marketing manager for UCON Fluids and Lubricants, the objective is to offer a high viscosity index, which allows for a wider range of viscosity. “He claims that it enables for an all-season product.
Sludging and varnishing, the gooey film that builds up and causes stickiness, friction, and heat transfer, all decrease efficiency and can lead to failure in high-load equipment like wind turbines, and the polyalkalene glycol lubricant can help.
Talk to Aaron Sage, chief operating officer of Sage Oil Vacuum in Amarillo, Texas, for a practical look at what goes into a regular wind turbine oil change. Since the mid-1990s, the company has specialized in wind turbine servicing. An oil change typically requires two maintenance employees, one on the ground and the other in the nacelle. Just under the gearbox, a 330-foot hose is dragged up into the nacelle’s yaw deck. Through a ball valve, the hose is connected to the gearbox. An air pressurizer on the ground is used to create a vacuum. Sage estimates that draining the roughly 80 gallons of oil from the gearbox at a pace of four to six gallons per minute will take around 30 minutes. Filling the gearbox can take another 30 minutes, making the entire fluid exchange process take up to two hours from start to finish.
A single two-person crew can perform up to four oil changes each day using Sage Oil’s equipment, which comes with either a 250-gallon or a 390-gallon tank. Since 2008, Sage Oil has installed 20 oil exchange systems throughout the United States. The majority of them are in Texas and Iowa, which have the most installed wind capacity. Depending on the choices, a system might cost anywhere from $40,000 to $65,000. Systems can be purchased outright or leased by an operator or service provider.
Lubrication and related services appear to be on the rise in the next years. For one thing, the number of wind turbines in operation continues to rise. For example, products are no longer covered by the manufacturer’s warranty. According to Lail, operators have the chance to work with service providers who have lubricant knowledge and experience to help maintain equipment for long-term availability and performance.
“According to him, customers have a great opportunity to assess items and procedures in order to increase efficiency.
In wind turbines, what kind of lubricant is used?
Lubricants come in a variety of forms. The synthetic lubricants used for wind turbine maintenance, which are mainly polyalphaolefin-based, can be further separated into hydraulic fluid, grease, and gear oil, which is the most essential synthetic lubricant for wind turbines.
What role does hydraulics play in wind turbines?
Hydraulic systems are critical for wind energy generating. Wind turbines rely on hydraulics to generate the required air density for energy generation. Hydraulics are applicable to all types of wind technology, making them a versatile solution for wind energy plant power needs.
Modern wind turbines use hydraulic systems for brake control, blade rotation regulation/setting, and spinning the blades to increase wind speed. A hydraulic powertrain with a rotor and blades is created via a hydraulic system consisting of hydraulic hoses and hose assemblies. The rotor blades of small turbines are usually fixed, whereas bigger turbines require blades with a pitch. The precise pitch of the turbine’s blades is ensured by a hydraulic reservoir, motor, pump, and other equipment. Hydraulic pitch control and a hydraulic battery can operate without the use of external power, saving energy. This results in a faster stopping time and a wider working temperature range.
Hydraulic systems are becoming more and more common in wind technologies across the industry as a more lightweight, more powerful, and less expensive alternative to electricity.
In wind turbines, what chemicals are used?
Europe has 106 gigawatts (GW) of installed wind turbine capacity by the end of 2012, enough to generate 231 terawatts of electricity in a normal year, or 7% of Europe’s demand. Between 210 and 230 GW of installed capacity is planned by 2020.
One of the most crucial aspects of wind turbine technology, the blades that transform wind into energy, is made of chlorine chemistry. The blades are light and flexible, yet sturdy enough to survive extremely high gusts, especially in offshore wind farms where winds are greater than onshore. They are made from layers of polyester, a chlorine-based substance.
The blades’ lightness is extremely significant. If the blades are heavy, it takes more wind energy to get them spinning and create electricity. This lowers the turbine’s total efficiency. Polyester is a lightweight and cost-effective option.
Versatile Epoxy Resin
Blade makers often utilize epichlorohydrin (EPI), an incredibly versatile chemical produced from chlorine that is used in a wide range of applications, to bind the layers of polyester together. Epoxy resins consume more than three-quarters of the world’s EPI output.
Epoxy resins, often known as structural or engineering adhesives, are utilized in applications that demand strong adhesion strength. The adhesives’ specific qualities can be customized to practically any application, allowing them to bond almost any material.
Epoxy resins work well as electrical insulators as well. They are employed in the generator, switches, and insulators of wind turbines because of this feature.
In a wind turbine, how much hydraulic oil is there?
At the moment, the average wind farm has 150 turbines. Each wind turbine requires 80 gallons of oil for lubrication, and this isn’t vegetable oil; this is a PAO synthetic oil based on crude… 12,000 gallons. Once a year, its oil must be replenished.
To power a city the size of New York, it is estimated that about 3,800 turbines would be required… For just one city, that’s 304,000 gallons of refined oil.
Now you must compute the total annual oil use from “clean” energy in every city across the country, large and small.
Not to add that the huge machinery required to construct these wind farms runs on gasoline. As well as the tools needed for setup, service, maintenance, and eventual removal.
Each turbine has a footprint of 1.5 acres, so a wind farm with 150 turbines would require 225 acres; to power a metropolis the size of NYC, 57,000 acres would be required; and who knows how much land would be required to power the entire United States. Because trees form a barrier and turbulence that interferes with the 20mph sustained wind velocity required for the turbine to work correctly, all of this area would have to be cleared (also keep in mind that not all states are suitable for such sustained winds). Cutting down all those trees is going to irritate a lot of tree-huggers who care about the environment.
A modern, high-quality, highly efficient wind turbine has a 20-year lifespan.
They can’t be reused, reconditioned, reduced, repurposed, or recycled on a budget, so guess what? They’re heading to specialized dumps.
What’s more, guess what else…? They’re already running out of space in these dedicated landfills for blades that have outlived their usefulness. Seriously! The blades range in length from 120 to over 200 feet, and each turbine has three of them. And this is despite the fact that wind energy currently serves only 7% of the country. Imagine if the remaining 93 percent of the country was connected to the wind grid… in 20 years, you’d have all those useless blades with nowhere to put them… Then another 20 years, and another 20 years, and so on.
I almost forgot to mention the 500,000 birds killed each year by wind turbine blade collisions, the most of which are endangered hawks, falcons, owls, geese, ducks, and eagles.
Smaller birds appear to be more agile, able to dart and dodge out of the way of the spinning blades, but larger flying birds appear to be less fortunate.
How much oil does it take to run a wind turbine?
For lubrication, each wind turbine requires 80 gallons of oil, which is not vegetable oil but a PAO synthetic oil based on crude 12,000 gallons. That oil must be replaced once a year.
Do turbines necessitate the use of oil?
According to Rushton, keeping a wind turbine’s gearbox properly oiled is critical to extending its life. Harnex 320, a wholly synthetic oil developed by Petro-Canada for use in wind turbine gearboxes, is designed to endure the harsh circumstances that wind turbines may face, such as severe temperatures or the risk of corrosion from saltwater for offshore wind turbines.
The type of oil used in a turbine’s gearbox, as well as all other sections of the machine, is usually specified by the original equipment manufacturer. One of the most important distinctions is whether the oil is synthetic or mineral.
For wind turbine gearboxes, Shell Global Solutions US Inc. offers both synthetic and mineral-based oil. Felix Guerzoni, a Shell Global Solutions Device Application Specialist and Team Lead, said one of the things the business considers when creating products is whether or not consumers can rely on the product to last a long period without requiring extra service.
“Because of the remoteness of these units, they’re only serviced every six months at best in terms of regreasing,” he said.
Customers want to utilize the gear oil and have it last anywhere from three to five years without having to change it, because there are some major expenditures associated with replacing the gear oil as well as having to change the gearbox out if the gearbox fails. The expense of renting specialty cranes is also significant.
However, the gearbox isn’t the only portion of the turbine that needs to be lubricated. The generator also needs to be lubricated, and the blades include lubrication sites. Wind tower blades are equipped with bearings that effectively feather the blade, allowing operators to adjust the blade angle to match the wind speed. The primary shaft bearing, as well as the drivetrain and yaw and pitch drives, all require grease for lubrication. The turbines additionally have a hydraulic system that may be utilized for hydraulic pitch control on the blades as well as providing a braking mechanism for the unit.
Multiple products may be necessary to maintain a single turbine due to all of these different elements requiring lubrication. Shell tries to make goods that may be used for various purposes when it is possible to do so without sacrificing quality, according to Guerzoni.
“We’re trying to optimize it as much as possible,” he said, explaining that the fewer lubricants a service engineer has to apply, the better. “Some firms will try to do a single solution, but you have to consider the unit’s overall reliability rather than trying to reduce the number of goods.” When it comes to greases, a product that is specifically created for that use will provide far higher performance and reliability. As a result, there’s a bit of a tradeoff.
ExxonMobil’s Americas Industrial Marketing Adviser, Travis Lail, said his business uses a similar approach to specializing lubricants for different elements of a wind turbine, but also tries to produce multifunctional products when quality isn’t a concern. Mobilgear SHC XMP 320 for turbine gear boxes, as well as Mobil SHC Grease 460 WT for main, pitch, and yaw bearings and Mobil SHC 524 lubricant for hydraulic systems, are among the company’s products for wind turbines.
He explained, “Our approach to the industry is to provide solutions that are tailored for certain uses.” “Of course, we endeavor to help customers satisfy their lubrication demands with the fewest number of right lubricants feasible.”
Companies don’t just focus at increasing the amount of potential applications while generating the greatest quality product in their research and development process. As turbine technology advances and corporations create larger wind turbines, lubricant manufacturers must likewise develop lubricants to stay up with the industry.
Larger turbines, according to Lail, require oil that can withstand the greater stress induced by their larger size.
“The gearbox actually adds to the load, and the end result is that it tests the oil’s ability to maintain a suitable film strength,” he explained. ” To ensure that you can enhance your oxidation resistance while maintaining low temperature fluidity, you must increase your additive packages and base oils.
Working directly with original equipment manufacturers is one approach to guarantee products are optimized for different wind turbines, according to Guerzoni.
“At this point, we have a very well-proven and successful product line,” he added, “but as these turbines grow in size, with higher towers, longer blade lengths, and higher megawatt classes, that’s introducing new issues and putting more stress on the unit and more stress on the oil.” “As a result, specifications are continuously changing, especially on the gear oil side, and as an oil provider, we’re continually looking at updates and changes in design trends and bringing out new solutions to suit those criteria.”
Turbine lubrication, on the other hand, is only one aspect of the equipment maintenance procedure at wind farms. According to Dennis Pruett, who manages GE Renewable Energy’s Services Global Operations, planned maintenance can include services like filter replacement and bolt torqueing, while unplanned maintenance can include electrical component failures and part replacements.
“Wind turbine maintenance is critical for the same reasons that regular car maintenance is critical,” he explained.
A turbine is a complicated equipment with a lot of moving components that has to deal with a lot of high loads, pressure, and stress on a daily basis.
Maintenance is necessary to keep the wind turbine operating at maximum capacity and efficiency.
GE Renewable Energy is a manufacturer of wind turbines as well as a provider of maintenance services. Many of GE Renewable Energy’s customers sign service agreements at the same time they buy their new units, and when the turbine is no longer under warranty, it goes through a post-warranty inspection, after which the owner decides whether to continue with the OEM as their service provider, use a third-party service provider, or self-perform maintenance, according to Pruett.
According to Pruett, GE Renewable Energy has more than 22,000 units deployed around the world, with around 6,000 of them still under warranty. Wind power generation in the United States has increased dramatically in recent years, owing to the present production tax credit. According to the American Wind Energy Association, 183 wind power projects were developed in 2012, resulting in 13 GW of new wind generating capacity. This is nearly double the 103 wind power projects that were completed in 2011.
“A wind turbine’s usual warranty is two years,” Pruett added, “so there will be a big number of turbines coming off warranty in the next several years.”
UpWind Solutions’ vice president of sales and marketing, Robert Bergqvist, anticipates the turbine repair sector to grow in the next years. UpWind Solutions, which manages over 13,000 turbines, is one of the third-party operations and maintenance businesses that turbine owners can choose to contract with instead of the original equipment manufacturer.
Asset management requirements for wind projects, according to Bergqvist, differ slightly from those for gas-fired or coal-fired plants.
“You’re going to have a pretty substantial expense associated with that replacement if you have one turbine down for unscheduled maintenance,” he said.
In terms of asset management, the difficulty in the wind sector is to be able to eliminate unscheduled repairs.
Bergqvist stated that his company considers grouping together different sorts of maintenance in order to avoid leasing cranes or other equipment on a long-term basis. If operators can identify ten units that are likely to fail at the same time, they can arrange a proactive replacement of those units at the same time.
He added that monitoring the equipment is a vital component of avoiding costly and unneeded repairs. UpWind Solutions provides operators with condition-based monitoring solutions that include obtaining oil samples, measuring gearbox vibrations, and employing software to continuously analyze unit performance based on oil temperature, rotation speed, and other data.
According to him, the combined results enable the organization to build “an intelligent, predictive analysis identifying anomalies and what will most likely break down.”
“You can extend the life of the unit if you can take care of problems before they become serious problems,” Bergqvist noted.