Wind turbines are unlikely to last much longer than this because of the extreme loads they are subjected to throughout their lives. This is partly due to the structure of the turbines themselves, since the turbine blades and the tower are only fixed at one end of the structure and therefore face the full force of the wind.
Of course, as the wind speed increases, so do the loads that turbines are subjected to. This can reach levels almost times greater than the design loads at rated wind speed, which is why many turbines are designed to shut down to protect themselves at higher wind speeds. One of the primary factors that determine the lifespan of a wind turbine are the environmental operating conditions faced by the wind industry. These conditions are site specific and include average wind speeds, turbulence intensities and for offshore wind farm operators the cyclic loading of foundations, jacket structures, and monopiles caused by waves.
In addition to these environmental factors, there are the usual concerns for any structure based around fatigue failure from use over the lifespan of the asset.
These include a variety of different parts and components, from wind turbine blades to wiring and hydraulic systems. Wind turbine blades need a special mention, as they are particularly prone to damage. As a moving component, the rotor blades are subject to higher levels of loading and fatigue, and can also suffer damage from birds or other objects striking them as well as the impact of high wind speeds or lightning strikes. The lifecycle of a turbine can be extended through careful monitoring and maintenance.
This requires the condition of the asset to be assessed and compared with the expended lifespan of the turbine, based upon the expected loads and fatigue as well as environmental factors for the wind energy site. These assessments will determine whether continued operation is possible and when any components may need replacing to extend the life of the overall structure.
This is known as a lifetime extension assessment and includes both theoretical and practical analysis, such as on-site inspections and the evaluation of design load data. A status report will detail the maintenance requirements, from which an accurate estimate of the cost of wind turbine lifetime extension can be generated.
This allows operators to determine the continued operational costs and risk of failure against the cost of replacement or even decommissioning. As mentioned above, the actual amount of maintenance required to keep a wind power asset in operation will vary depending upon factors including specific operating conditions and the materials used.
However, wind turbines generally require preventative maintenance check-ups two or three times per year. The need for these check-ups may need to increase as the turbine ages and also requires more maintenance to keep it in operation.
Offshore power generation assets face their own set of particular challenges to maintain. The challenges faced by onshore assets are often exacerbated by the offshore operating conditions while also adding their own specific problems. These challenges include corrosion, erosion and biofouling alongside the usual materials, fatigue and wind-based factors. As the reliance on offshore renewable energy sources grows, it will become increasingly important to address these challenges to maintain operational availability.
In order to maintain safe operation, it is important to establish the structural stability of wind turbines. Safety devices, braking systems and turbine control systems all require testing in order to verify the structural stability but there is also a need to compare the design conditions loads to the actual loads the turbine has been exposed to. This loading information can be obtained from computer simulations representing design conditions after type testing alongside environmental operating conditions.
The environmental operating conditions include site-specific wind conditions, such as average wind speeds, turbulence, and any extreme weather events. 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.
Scientists are trying to find better ways to separate resins from fibers or to give small chunks new life as pellets or boards. In the European Union, which strictly regulates material that can go into landfills, some blades are burned in kilns that create cement or in power plants.
But their energy content is weak and uneven and the burning fiberglass emits pollutants. In a pilot project last year, Veolia tried grinding them to dust, looking for chemicals to extract. One start-up, Global Fiberglass Solutions , developed a method to break down blades and press them into pellets and fiber boards to be used for flooring and walls. It plans another operation in Iowa. Until then, municipal and commercial dumps will take most of the waste, which the American Wind Energy Assn.
California ditched coal. Southern California Gas is engaged in a wide-ranging campaign to preserve the role of its pipelines in powering society. It pointed to an Electric Power Research Institute study that estimates all blade waste through would equal roughly 0. In Iowa, Waste Management Inc.
The largest U. Another model being seen more in the U. Many existing models and new ones being introduced reach well over feet in total height. See the specs for several models at AWEO. How are the wind turbine components transported?
Transport of such large items and the cranes needed to assemble them often presents problems in the remote areas where they are typically built. Roads must be widened, curves straightened, and in wild areas new roads built altogether.
What kind of platform is a wind turbine set in? The steel tower is anchored in a platform of more than a thousand tons of concrete and steel rebar, 30 to 50 feet across and anywhere from 6 to 30 feet deep. Shafts are sometimes driven down farther to help anchor it. Mountain tops must be blasted to create a level area of at least 3 acres. The platform is critical to stabilizing the immense weight of the turbine assembly. How much do wind turbines weigh? In the GE 1.
The corresponding weights for the Vestas V90 are 75, 40, and , total tons; and for the Gamesa G87 72, 42, and , total tons. What is the nacelle?
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