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Apparently this cart settled some longstanding physics dispute... Would there be a way to think of something similar using solar wind? *no clue*

the counterintuitive aspect in my view is not the travelling against he wind but the faster than wind travelling with the wind, where the simple trick of having the wheels power the propeller flips the mind to understand it easily ... (http://www.wired.com/autopia/2010/06/downwind-faster-than-the-wind/)

But from that point of view it should also be counter-intuitive that it travels against the wind at twice the speed of the wind...

additional information: http://atelierdna.com/?p=144

isn't this a bit of a contradiction: on the one hand: "Based on rough estimates, said Núñez-Ameni the output would be comparable to that of a conventional wind farm covering the same area" and on the other: "After completion, a Windstalk should be able to produce as much electricity as a single wind turbine, with the advantage that output could be increased with a denser array of stalks. Density is not possible with conventional turbines, which need to be spaced about three times the rotor's diameter in order to avoid air turbulence. " still, very interesting concept!

Using a sophisticated weather model, environmental engineers at Stanford have defined optimal placement of a grid of four wind farms off the U.S. East Coast. The model successfully balances production at times of peak demand and significantly reduces costly spikes and zero-power events.

What he found was that wind turbines "could disrupt a hurricane enough to reduce peak wind speeds by up to 92 mph and decrease storm surge by up to 79%."

It seems the topic is getting more and more popular and is no longer considered fringe research, as this is a paper from nature climate change!

With extreme precision, the possibility of getting information from the perturbations gives nice side effects

They say it will not replace current wind speed dropsondes which have a ten times better wind speed accuracy, but they could definitely provide a much more extensive view of cyclone wind speeds - at a very low cost!

It could be interesting to compare the accuracy and spatial resolution of the GPS method compared to what can be achieved using L-Band SAR data (e.g. SMOS mission)...

In Spain, 53% of the energy demand could be supplied by wind farms (during one weekend with quite strong winds)!!!!

Indeed! they have also among the biggest wind farms in Europe. For instance, if you drive from Algeciras (and Gibraltar) to Tarifa, you can see them rotating like hell!!

"The old model is no longer valid for the ocean's overturning, not because it's a gross simplification, but because it ignores crucial elements such as eddies and the wind field. The concept of a conveyor belt for the overturning was developed decades ago, before oceanographers had measured the eddy field of the ocean and before they understood how energy from the wind impacts the overturning,"

After previously investing in the company, Google has now acquired Makani Power, a green energy startup that is currently building airborne wind turbines. The acquisition was first reported in Brad Stone's Businessweek story about Google X, and judging from Stone's story, the team will join Google X.

some biomimicry used in energy systems... maybe it sparks some ideas

not much new that has not been shared here before ... BUT: we have done relativley little on any of them. for good reasons?? don't know - maybe time to look into some of these again more closely Energy Efficiency( Termite mounds inspired regulated airflow for temperature control of large structures, preventing wasteful air conditioning and saving 10% energy.[1] Whale fins shapes informed the design of new-age wind turbine blades, with bumps/tubercles reducing drag by 30% and boosting power by 20%.[2][3][4] Stingray motion has motivated studies on this type of low-effort flapping glide, which takes advantage of the leading edge vortex, for new-age underwater robots and submarines.[5][6] Studies of microstructures found on shark skin that decrease drag and prevent accumulation of algae, barnacles, and mussels attached to their body have led to "anti-biofouling" technologies meant to address the 15% of marine vessel fuel use due to drag.[7][8][9][10] Energy Generation( Passive heliotropism exhibited by sunflowers has inspired research on a liquid crystalline elastomer and carbon nanotube system that improves the efficiency of solar panels by 10%, without using GPS and active repositioning panels to track the sun.[11][12][13] Mimicking the fluid dynamics principles utilized by schools of fish could help to optimize the arrangement of individual wind turbines in wind farms.[14] The nanoscale anti-reflection structures found on certain butterfly wings has led to a model to effectively harness solar energy.[15][16][17] Energy Storage( Inspired by the sunlight-to-energy conversion in plants, researchers are utilizing a protein in spinach to create a sort of photovoltaic cell that generates hydrogen from water (i.e. hydrogen fuel cell).[18][19] Utilizing a property of genetically-engineered viruses, specifically their ability to recognize and bind to certain materials (carbon nanotubes in this case), researchers have developed virus-based "scaffolds" that

Siemens is using neural networks to improve operation of wind turbines, reducing maintenaince needs and improving output by one precent. It seems even that Siemens has quite a large neural network study group, probably linked to german universities, with various examples in practice (see websie)

Australian government approved the construction of one of the biggest wind farms of the world

Following a discussion with Oisin maybe a kite type wind turbine would be an interesting alternative on Mars

Maglev) wind power generator

Interesting to see the size of the tree doesn't influence the amount of wind it can stand against. Of particular interest to know when you can have a tree falling in your house/car here in the Netherlands

http://youtu.be/hbPXXpaW5ws Andrés: I am sure you remember Tiago's project for the Azores ... cheers Leopold

I hate scorpions, but this could be a nice subject for a future Ariadna study! This north African desert scorpion, doesn't dig burrows to protect itself from the sand-laden wind (as the other scorpions do). When the sand whips by at speeds that would strip paint away from steel, the scorpion is able to scurry off without apparent damage.

Nice research, though they have done almost all the work that we could do in an Ariadna, didnt they? "To check, they took further photographs. In particular, they used a laser scanning system to make a three-dimensional map of the armour and then plugged the result into a computer program that blasted the virtual armour with virtual sand grains at various angles of attack. This process revealed that the granules were disturbing the air flow near the skeleton's surface in ways that appeared to be reducing the erosion rate. Their model suggested that if scorpion exoskeletons were smooth, they would experience almost twice the erosion rate that they actually do. Having tried things out in a computer, the team then tried them for real. They placed samples of steel in a wind tunnel and fired grains of sand at them using compressed air. One piece of steel was smooth, but the others had grooves of different heights, widths and separations, inspired by scorpion exoskeleton, etched onto their surfaces. Each sample was exposed to the lab-generated sandstorm for five minutes and then weighed to find out how badly it had been eroded. The upshot was that the pattern most resembling scorpion armour-with grooves that were 2mm apart, 5mm wide and 4mm high-proved best able to withstand the assault. Though not as good as the computer model suggested real scorpion geometry is, such grooving nevertheless cut erosion by a fifth, compared with a smooth steel surface. The lesson for aircraft makers, Dr Han suggests, is that a little surface irregularity might help to prolong the active lives of planes and helicopters, as well as those of scorpions."

What bugs me (pardon the pun) is that the dimensions of the pattern they used were scaled up by many orders of magnitude, while "grains of sand" with which the surface was bombarded apparently were not... Not being a specialist in the field, I would nevertheless expect that the size of the surface pattern *in relation to* to size of particles used for bombarding would be crucial.

The Global Warming Policy Foundations has warned policy makers that wind energy is an extraordinarily expensive and inefficient way of reducing CO2 emissions.

Vertical windmills based on fish fins and school swimming behaviour