Floating wind turbine development
Energy trend towards renewables
Floating wind turbines are a relatively new concept to comply with the society's growing demand for energy. While the energy market is still dominated by non-renewables, such as oil (30%) and coal (28%), a shift is occurring towards more renewable types of energy.
This shift in the energy trend can best be explained by three reasons:
This shift in the energy trend can best be explained by three reasons:
- The available oil and gas fields are slowly getting depleted, resulting in the necessity of finding an long term alternative solution.
- Studies linking the large increase of emission gases in the atmosphere (due to the conventional energy sources) to the global warming phenomena have further put pressure on the industry to find more sustainable alternatives.
- Technological innovations have increased the efficiency of wind turbines (and the other various renewables) to a level that it is a feasible economical option for large scale energy production.
Wind turbines: Onshore to Offshore
In order to meet the increasing demand for sustainable energy ever since the 1980s, large onshore wind farms have been installed at numerous places. The world's first wind farm was 0.6 MW, consisting of 20 wind turbines rated at 30 kilowatts each, installed in southern New Hampshire in December 1980. Onshore placement seemed the most sensible choice, since the production/installation/maintenance is favorable due to the turbine being easily accessible.
The production of onshore wind farms continued steadily until the late 1990s, when the first problems arose. With the increasing occupation of land onshore, wind turbines would have to be placed closer to existing living areas. This unwanted development caused societal groups to get a 'Not In My Backyard' (NIMBY) attitude regarding the closing in by the onshore wind turbines.
To find alternatives for this public matter, tests were conducted to build wind farms offshore. This would not only be a good solution to counteract the NIMBY attitude, but at sea the wind generally blows faster at a higher consistency, which results in a higher energy production. The main downside of the transition to offshore wind turbines is that the CAPEX and OPEX are higher than the onshore equivalent.
The production of onshore wind farms continued steadily until the late 1990s, when the first problems arose. With the increasing occupation of land onshore, wind turbines would have to be placed closer to existing living areas. This unwanted development caused societal groups to get a 'Not In My Backyard' (NIMBY) attitude regarding the closing in by the onshore wind turbines.
To find alternatives for this public matter, tests were conducted to build wind farms offshore. This would not only be a good solution to counteract the NIMBY attitude, but at sea the wind generally blows faster at a higher consistency, which results in a higher energy production. The main downside of the transition to offshore wind turbines is that the CAPEX and OPEX are higher than the onshore equivalent.
In 2000, the first major European investments in offshore wind farms were done and it soon proved to be a serious alternative within the renewable energy industry. Future optimizations to improve the efficiency of wind turbines substantiate the choice of offshore wind turbines even more, since the steady winds at sea use that extra efficiency to the fullest.
Currently innovations focus on the improvement of the turbine blades, new or optimized drive systems and the infrastructure to export the energy to shore, where it is distributed.
Currently innovations focus on the improvement of the turbine blades, new or optimized drive systems and the infrastructure to export the energy to shore, where it is distributed.
Wind Turbines: Fixed to Floating
Even though the concept for floating wind turbines was introduced in 1972 already (by Prof. W.E. Heronemus - University of Massachusetts Amherst), it would take another 20 years before the offshore wind technology had grown maturely for the research community to further invest possibilities for the floating variety.
The use of floating wind turbines would also enable placement of wind farms at deep-water wind resources, which are extremely abundant in subsea areas worldwide. Bottom founded wind turbines are limited to shallow waters only and generally become economically unfeasible w.r.t. floating turbines for waters deeper than 50 meter. Two-thirds of the North Sea is between 50 and 220 meters deep, so many opportunities are to be exploited with regards to strategic high efficiency wind farm placement.
It has other environmentally beneficial points too. Floating turbines avoid the risk of damaging fragile seabed ecosystems. And thanks to their location out of sight of land, they avoid being shot down by the 'visual impact' campaigns which are getting increasing support as the number of onshore/near-shore wind turbines grows.
While current general wind turbine developments continue, the main challenge for further optimizing the floating turbines is the issue of stability and mooring. The deep-water wind prone areas are generally subjected to harsher sea states than the near-shore fixed wind turbines. Combined with the (desired) strong wind conditions, the stabilization of the floating systems are required to withstand these rough environmental conditions. This has resulted in a variety of different stabilizing and mooring mechanisms, which are each engineered to be used in a specific range of environmental conditions, such as the water depth and the wave height.
These technologies are explained into more detail in the Technology page.
While current general wind turbine developments continue, the main challenge for further optimizing the floating turbines is the issue of stability and mooring. The deep-water wind prone areas are generally subjected to harsher sea states than the near-shore fixed wind turbines. Combined with the (desired) strong wind conditions, the stabilization of the floating systems are required to withstand these rough environmental conditions. This has resulted in a variety of different stabilizing and mooring mechanisms, which are each engineered to be used in a specific range of environmental conditions, such as the water depth and the wave height.
These technologies are explained into more detail in the Technology page.