How long are windmill turbine blades

Turbine blades can last up to 20 years, but many are taken down after just 10 so they can be replaced with bigger and more powerful designs. Tens of thousands of aging blades are coming down from steel towers around the world and most have nowhere to go but landfills. In the U. Europe, which has been dealing with the problem longer, has about 3, coming down annually through at least , according to BloombergNEF.

To prevent catastrophic climate change caused by burning fossil fuels, many governments and corporations have pledged to use only clean energy by Wind energy is one of the cheapest ways to reach that goal. The electricity comes from turbines that spin generators. Modern models emerged after the Arab oil embargo, when shortages compelled Western governments to find alternatives to fossil fuels.

The first wind farm in the U. The first models were expensive and inefficient, spinning fast and low. After , when Congress passed a tax credit, manufacturers invested in taller and more powerful designs. Their steel tubes rose feet and sported swooping fiberglass blades. A decade later, General Electric Co. But the fiberglass blades remain difficult to dispose of.

With some as long as a football field, big rigs can carry only one at a time, making transportation costs prohibitive for long-distance hauls. The power rating of the turbine is about eight megawatts. This turbine has a rotor diameter of about feet. It is one of the largest onshore turbines in production. Development toward serial production of this Chinese turbine has been a bit slow, but the design is very compact and features just two blades.

The prototype is about feet in diameter, and the company is also working on larger variants. With an output of about six megawatts, the design features blades specifically designed in Germany. The other main parts are built in China. The prototype turbine has a rotor diameter of about feet, while the current model spans about feet.

The company says the longer blade length will increase yield and will improve the operating life of the turbine by about five years. With a rotor diameter of about feet, the turbine has been chosen to power projects located off the coast of France and in the North Sea near Germany. The six-megawatt unit features a rotor diameter of about feet, but an extended version of the turbine spans about feet.

Many scientists project that in the coming decades, the size of wind turbines could dwarf those of today. At this point, no extra power will be generated no matter how much faster the wind blows.

The cutoff speed for most turbines is at 55 miles per hour, where the rotors shut off to prevent damage to the internal components. Denser air is heavier and carries more mass, which creates more lift on the blades.

Regions with denser air are more valuable for potential wind farms. The density of the air is a function of temperature, elevation, and air pressure. Cold air is denser than hotter air, lower elevations are denser than higher ones, and high-pressure systems are denser than low-pressure systems.

The denser air at sea level provides more energy for the same wind speed compared to winds at higher altitudes. In , GE unveiled its massive Haliade-X offshore wind turbine. This gargantuan machine has a rated capacity between 12 MW and 14 MW. The tower is meters tall, but from base to blade tip, the turbine is a whopping meters tall. The Haliade-X can power a home for two days with just one rotation, and a single turbine can generate 74 GWh of electricity annually. The blades on the Haliade-X measure about meters long.

It would take Hussein Bolt, who holds the world record for the fastest running speed, about ten seconds to run from end to end. The blades of the Haliade-X may just be among the single largest machine components ever built. Compared to other turbines in its class, it can begin generating power at lower wind speeds. Its low rotational inertia allows the rotor to continue spinning even when strong winds die down. With turbines like the Haliade-X pushing the envelope of turbine size, one must ask: is there a limit?

The blades can only get so long before it starts to bend and flex, risking a possible collision with the tower. At some point, the laws of physics will put a cap on the maximum turbine size. Ambitiously large turbines are being designed as we speak. These analytical calculations are used to create a statement citing any immediate actions that are required for continued operation, along with those that will need to be scheduled for a later date, such as the replacement of parts or a full inspection.

All of these simulations need to be backed up by on-site inspections. This has traditionally been undertaken in-person by an inspector, but is increasingly being done remotely using robots and technologies such as the BladeSave system.

Find out more about the BladeSave Project. The condition of a wind turbine is assessed through an on-site inspection that is informed by the analytical assessment.

This allows for specific weaknesses, defects or potential problems to be checked. Physical monitoring also looks for unusual wear or damage to components and equipment. Load-bearing and safety critical components require particular attention, with some types of wind turbine having their own design flaws or production issues that could lead to premature defects. Physical checks are performed on the turbine blades, the supporting structure and the foundation to look for signs of corrosion and cracking or to audibly listen for suspicious or unusual noises from the gear and bearing assemblies.

Significant damage can lead to the immediate shutdown of an asset, often incurring costly downtimes ahead of maintenance or repair. However, these checks tend to locate minor damage caused by corrosion, fatigue or weathering, allowing the defect to be fixed before it gets any worse. Different parts require different levels of monitoring and maintenance, with turbine blades and cables requiring higher levels of inspection and care.

Physical monitoring also refers to monitoring the surrounding environment, and how this may influence the turbulence and wind speeds used in the analytical assessment.

Manufacturers are working on new designs to help reduce these costs by creating turbines that require fewer service visits and, consequently, less downtime. However, costs for repair and replacement parts are more difficult to ascertain as they can be influenced by the age and condition of the turbine, frequently increasing as the asset ages. In addition, as very few turbines have reached the end of their life expectancy, there is little data on these costs later on the lifecycle, while many older turbines are smaller than those currently on the market.

Wind farm operators are faced with business decisions as their assets age — whether to continue operation, repower or to decommission. These decisions are affected by the physical condition compared to the theoretical lifetime of the turbines. On-site inspections and monitoring tools help evaluate these factors to ensure wind farms operate safely within their design lifetime. This lifetime can be extended or shortened, depending on damage caused by environmental factors and fatigue.