Sooner or later somebody was going to realize that you can harvest wind power from high altitudes while using just a fraction of the materials needed to build a conventional turbine, and it looks like the race is on between Google-owned Makani and a Dutch startup called Ampyx to see who can get there first.
Wind Power From The High Skies
Wind at higher altitudes blows stronger and steadier, which explains why conventional wind turbines keep getting bigger, with taller towers and longer blades.
That all translates into more materials and greater expense. A potentially more economical approach to wind power involves ditching the tower and floating a wind harvesting device in the air.
Tethered to a stationary platform by a cable, the drone-like device circles at high altitudes. The sticky wicket is transferring that motion into wind power generation.
The Ampyx system achieves the transference by guiding its drone in a figure eight pattern. As the drone moves along its pathway, it pulls the tether in and out. The end of the tether is connected to a winch drum system that generates electricity.
In the latest development for Ampyx, the involvement of E.ON has enabled the company to begin planning for an advanced, $3.7 million R&D facility and control center near Winchelsea, England.
The idea is to test the combined system of platform, drone and tether in a grid-connected environment.
Tiny Startup Has A Fighting Chance
Ampyx better act fast if it’s going to catch up to Google’s Makani, but the simplicity of its concept could give it an edge.
The Makani approach to high altitude wind power is somewhat more ambitious — as in, more complicated. The technology caught the eye of Google, which acquired the company in 2013. When CleanTechnica checked in on Makani in 2014, the company was still facing significant regulatory obstacles including wildlife preservation issues aside from the technological challenges.
Nevertheless, in May of this year Makani reported that its 600-kilowatt, eight-rotor “energy kite” produced power for the first time.
That sounds great, but the there’s one catch: according to our friends over at Renewables Now, the prototype was consuming more electricity than it produced.
Onwards And Upwards For High Altitude Wind Power
Not too long ago wind-harvesting kites were slotted into the oddball category of renewable energy technology, but as the science matures, A-list investors like Google and E.ON are willing to park their Benjamins there.
Makani and Ampyx are just two companies developing credible track records in the field.
Another up and comer is Kite Power Systems, which just nailed down a £2 million equity investment from the Scottish Investment Bank.
Keep your eye on Italy’s KiteGen Research, too. The company appears to be on track for production, based on a blog post last spring indicating that the wings of its airborne device will be produced in a newly opened composites manufacturing plant.
Where To Put Your New Airborne Wind Harvesting Device
For some of these new systems wildlife preservation issues could limit land-based applications, but carefully sited offshore platforms could resolve that problem.
Once the technology matures, small scale “energy kites” could also find homes in the oceangoing container shipping field.
Innovation in the airborne wind harvesting field has also revived interest in sail-powered seacraft.
Back in 2008, the US Navy chartered a “kite-powered cargo ship” that deployed a computer-controlled retractable sail on a 100-yard tether.
Fast forward to 2017, and we find Business Insider reporting on a “spinning sail” wind harvesting device that shipping giant Maersk is planning to install on one of its ships as a retrofit.
This device, from the company Norsepower, differs significantly from the ones described above. It sits on the ship like a tall smokestack without the smoke. The Rotor Sail creates a thrust as air passes through it, enabling the vessel to use less fuel.
The fuel savings is more than enough to make up for the relatively small amount of electricity needed to spin the device. Here’s an explainer from Norsepower:
The Norsepower Rotor Sail Solution is a modernized version of the Flettner rotor – a spinning cylinder that uses the Magnus effect to harness wind power to propel a ship. When the wind conditions are favourable, Norsepower Rotor Sails allow the main engines to be throttled back, saving fuel and reducing emissions while providing the power needed to maintain speed and voyage time.
Norsepower’s contribution does have something important in common with tether-based systems as well as conventional wind turbines: new, lightweight materials and advanced software that provide for greater efficiencies.
That’s something to keep in mind the next time you hear anybody scoff at “wind mills.”
Image: via E.ON.