New developments can reduce costs eg. single mooring point around which a floating turbine swivels to catch the wind. The narcelle does not rotate, so no yaw drive or motor, the various floating foundations, some with tension structures are up 4 to 8 times lighter than most current spar and semi-submersible floating foundations . There are number of EU programs to see if this is worthwhile, cost reductions, varying wind and wave directions, reduced output, etc.
Hexicon TwinWind 2 x 3-15 MW innovative (6-30MW) floating twin turbine with one point mooring (no yaw control/motor) https://www.hexicongroup.com/twinwind/
Mingyang OceanX 2 x 8.3MW (16.6MW) floating offshore wind turbine with tensegrity structure and one point mooring (no yaw control/motor) but 2 blades broke before it was installed !!
Touchwind single horizontal/tilted rotor with now semi-submersible, probably tension leg 3 point mooring floating foundation (no yaw control/motor) https://touchwind.org/
The extraction of wind energy in such a large scale will change the weather and climate. Since extracting energy from the airflow reduces inevitable the air flow. Therefore the transport of moisture from the sea to the continents and the balancing of temperature differences is reduced. Probably it will even change the atmospheric current pattern, air flow is preferred, which circumvents the energy sink of the wind turbines. So a large scale energy generation by wind turbines will inevitable result in more droughts and more weather extremes. So large scale wind energy generation will result in a human-caused climate change. A detailed calculation of the maximum extractable wind energy can be found in the publication from Axel Kleidon: "Physical limits of wind energy within the atmosphere and its use as renewable energy: From the theoretical basis to practical implications" Meteorol. Z. (Contrib. Atm. Sci.), Vol. 30, No. 3, 203–225 (2021). According to this publication only 0,6 W/m² wind energy can be generated (average over large area). Independent of the construction of the wind turbines. And is obvious, that the influence on the atmospheric circulation will increase as the local energy extraction converge to this limit. Therefore I would estimate that the energy extraction should be blow 5% in order to limit the climatic impact of the wnd energy generation. Which corresponds to an energy generation of about 0,03 W/m² or about 67 TWh/year for GB, which is far below energy demand of an industrialized GB.
Your claims of climate effects from wind power are not supported by the academic paper that you cite below and are not supported by the sceince. As for limitations in wind energy, local wake effects are already well known. These are taken into account by the wind industry and I am confident about the accuracy of the projections for offshore wind that I quote in the blog post. Offshore windfarms, of which there is an increasing quantity, are profitable and increasingly cheaper.
In the mentioned publication describes the atmospheric circulation as a heat engine. According to this calculation the resource potential is only about 0,5 -0.6W/m². You can find the detailed calculation in the mentioned publication of A. Kleidron.
This publication does not directly discuss the effect of the wind energy extraction on the climate. However the mentioned effects can be directly derived from thermodynamics. The energy of the atmospheric circulation is generated be the energy flow between the hot and the cold zones of the earth (Thermodynamic heat engine). And the generated mechanical energy is dissipated be the surface friction of the airflow. The corresponding (local) equilibrium determines the speed of the airflow. If some of the wind energy is extracted by wind turbines there is less energy available to overcome the surface friction. Therefore the speed of the airflow is reduced. By this way heat energy transfer is reduced, which inevitable increases temperature differences. Furthermore, as the airflow transfers moisture from the sea to the continents, a reduced airflow will result in lower precipitation and more droughts. As an example the weather data of Germany show these effects. Between 2000 and 2022 the wind energy generation increases by about 6 TWh per year, while the precipitation decreases by about 8 mm and the temperature increases by about 0,04 K per year. In contrast, between 1880 and 2000 temperature and precipitation were positively correlated. This observations are in good agreement with the above mentioned climate effects which can be expected from large scale wind power generation. Regarding the influence of the wind energy extraction on large scale circulation patterns the issue is more complicated, as the weather pattern is basically chaotic. Nevertheless large scale wind energy extraction should favor circulation patterns which reduced energy loss due to the wind turbines (in addition to the influence of the landscape). But that could not discussed within a few lines.
well you'd better tell all of these increasing number of companies operating offshore windfarms that they are shouldn't be getting the electricity production that are doing
The Kitegen Powerwing 3MW model is relatively simple with a :
- ground based generator
- ground based control (2 tethers)
- large semi-flexible rigid wing to withstand high forces (soft fabric wing only up to 1MW)
- multiple units can be stacked in time and space to maximise output
- 400 metre altitude proposed but higher is better (power cube law)
- but requires some breeze at ground to launch so it uses a telescopic revolving arm to launch and fans in low wind speeds
So
- no kite attached controls
- no electric cable from kite to ground
- no ultra high speeds (and stresses) required to turn propellers (Manaki and others)
With the development of drone technology you can with a small rechargeable battery and folding props self launch, recharge and retrieve eg Skypull but it seems to have fallen by the wayside.
The floating platform/hull can be combined with a wave / tidal generator eg Wello Penguin in hull pendulum / WaveSwell improved Oscillating Water Column device / tidal device Orbital Marine O2 .
Thanks Dave. I aim to attend online in person hybrid lecture by Prof Atilla Incecik Glasgow 14th January. A lot hanging on further development of floating offshore WT!
New developments can reduce costs eg. single mooring point around which a floating turbine swivels to catch the wind. The narcelle does not rotate, so no yaw drive or motor, the various floating foundations, some with tension structures are up 4 to 8 times lighter than most current spar and semi-submersible floating foundations . There are number of EU programs to see if this is worthwhile, cost reductions, varying wind and wave directions, reduced output, etc.
X1 Wind floating turbine with one point mooring https://www.x1wind.com/x1wind-technology/
Aerodyn Nezzy 2 x 7.5 MW innovative (15MW) floating twin turbine with one point mooring (no yaw control/motor) http://aerodyn-engineering.com/scd-technology-scd-nezzy/
Hexicon TwinWind 2 x 3-15 MW innovative (6-30MW) floating twin turbine with one point mooring (no yaw control/motor) https://www.hexicongroup.com/twinwind/
Mingyang OceanX 2 x 8.3MW (16.6MW) floating offshore wind turbine with tensegrity structure and one point mooring (no yaw control/motor) but 2 blades broke before it was installed !!
https://reneweconomy.com.au/mingyangs-two-headed-floating-wind-turbine-begins-operations-despite-fractures-in-giant-blades/
Touchwind single horizontal/tilted rotor with now semi-submersible, probably tension leg 3 point mooring floating foundation (no yaw control/motor) https://touchwind.org/
The extraction of wind energy in such a large scale will change the weather and climate. Since extracting energy from the airflow reduces inevitable the air flow. Therefore the transport of moisture from the sea to the continents and the balancing of temperature differences is reduced. Probably it will even change the atmospheric current pattern, air flow is preferred, which circumvents the energy sink of the wind turbines. So a large scale energy generation by wind turbines will inevitable result in more droughts and more weather extremes. So large scale wind energy generation will result in a human-caused climate change. A detailed calculation of the maximum extractable wind energy can be found in the publication from Axel Kleidon: "Physical limits of wind energy within the atmosphere and its use as renewable energy: From the theoretical basis to practical implications" Meteorol. Z. (Contrib. Atm. Sci.), Vol. 30, No. 3, 203–225 (2021). According to this publication only 0,6 W/m² wind energy can be generated (average over large area). Independent of the construction of the wind turbines. And is obvious, that the influence on the atmospheric circulation will increase as the local energy extraction converge to this limit. Therefore I would estimate that the energy extraction should be blow 5% in order to limit the climatic impact of the wnd energy generation. Which corresponds to an energy generation of about 0,03 W/m² or about 67 TWh/year for GB, which is far below energy demand of an industrialized GB.
Your claims of climate effects from wind power are not supported by the academic paper that you cite below and are not supported by the sceince. As for limitations in wind energy, local wake effects are already well known. These are taken into account by the wind industry and I am confident about the accuracy of the projections for offshore wind that I quote in the blog post. Offshore windfarms, of which there is an increasing quantity, are profitable and increasingly cheaper.
In the mentioned publication describes the atmospheric circulation as a heat engine. According to this calculation the resource potential is only about 0,5 -0.6W/m². You can find the detailed calculation in the mentioned publication of A. Kleidron.
This publication does not directly discuss the effect of the wind energy extraction on the climate. However the mentioned effects can be directly derived from thermodynamics. The energy of the atmospheric circulation is generated be the energy flow between the hot and the cold zones of the earth (Thermodynamic heat engine). And the generated mechanical energy is dissipated be the surface friction of the airflow. The corresponding (local) equilibrium determines the speed of the airflow. If some of the wind energy is extracted by wind turbines there is less energy available to overcome the surface friction. Therefore the speed of the airflow is reduced. By this way heat energy transfer is reduced, which inevitable increases temperature differences. Furthermore, as the airflow transfers moisture from the sea to the continents, a reduced airflow will result in lower precipitation and more droughts. As an example the weather data of Germany show these effects. Between 2000 and 2022 the wind energy generation increases by about 6 TWh per year, while the precipitation decreases by about 8 mm and the temperature increases by about 0,04 K per year. In contrast, between 1880 and 2000 temperature and precipitation were positively correlated. This observations are in good agreement with the above mentioned climate effects which can be expected from large scale wind power generation. Regarding the influence of the wind energy extraction on large scale circulation patterns the issue is more complicated, as the weather pattern is basically chaotic. Nevertheless large scale wind energy extraction should favor circulation patterns which reduced energy loss due to the wind turbines (in addition to the influence of the landscape). But that could not discussed within a few lines.
well you'd better tell all of these increasing number of companies operating offshore windfarms that they are shouldn't be getting the electricity production that are doing
More radical is kite wind power which can substantially reduce the quantity of concrete and steel.
See an EROEI analysis by Euan Means from 2016
kite based wind turbines >300, much better than standard HAWT (Horizontal Axis Wind Turbines) at ~ 20 http://euanmearns.com/the-eroei-of-high-altitude-wind-power/
The Kitegen Powerwing 3MW model is relatively simple with a :
- ground based generator
- ground based control (2 tethers)
- large semi-flexible rigid wing to withstand high forces (soft fabric wing only up to 1MW)
- multiple units can be stacked in time and space to maximise output
- 400 metre altitude proposed but higher is better (power cube law)
- but requires some breeze at ground to launch so it uses a telescopic revolving arm to launch and fans in low wind speeds
So
- no kite attached controls
- no electric cable from kite to ground
- no ultra high speeds (and stresses) required to turn propellers (Manaki and others)
With the development of drone technology you can with a small rechargeable battery and folding props self launch, recharge and retrieve eg Skypull but it seems to have fallen by the wayside.
The floating platform/hull can be combined with a wave / tidal generator eg Wello Penguin in hull pendulum / WaveSwell improved Oscillating Water Column device / tidal device Orbital Marine O2 .
Thanks Dave. I aim to attend online in person hybrid lecture by Prof Atilla Incecik Glasgow 14th January. A lot hanging on further development of floating offshore WT!