Producing Energy with … Drones?!

Drones can be used in lots of ways. They can shoot great videos. They can patrol borders and monitor gas pipelines. They can help with mapping and precision agriculture. Amazon experiments with a drone delivery service.

Surprisingly, drones can also produce energy. Wind energy to be precise.

How?

Producing wind energy with drones is simple, just follow the instructions:

  • Take a fully autonomous plane-like drone.
Yes, I am a drone and yes, I produce wind energy. © Ampyx Power
  • Attach the drone to a tether and fly the drone in the wind like a surf kite. Fly in circles to collect large amounts of wind energy.
Wind Drones: electricity generation in the air (first picture) and on the ground (pumping mode, second and third picture) © Daidalos Capital
  • Mount mini wind turbines and generators on the drone and produce the energy in the air (first picture). The electricity will be conducted to the ground via a power cable that is built into the tether.
  • Alternatively, produce electricity on the ground. Let the drone pull on the tether (blue arrow, second picture). On the ground, the tether is wound around a drum which is connected to a generator. When the drone pulls on the tether, the tether unwinds from the drum, turns the generator and produces electricity.
  • When the tether is fully reeled out, let the drone nosedive towards the ground station and quickly reel in the tether (third picture).
  • Let the drone fly until you have fully replaced coal, oil and gas as energy sources and have solved our climate crisis. Then relax and enjoy life.

For the last step you will need more than one Wind Drone. But one for every 500 people will do the trick.

This is all the magic behind Wind Drones.

If it’s so simple, why haven’t we done it long ago? Right, we did not have the drone.

OK, we now have drones and can use them to produce wind energy, but why should we? Are they any better than wind turbines?

They are better in reaching the winds at higher altitude. Winds at higher altitude are stronger and steadier. So we want to go as high as possible to produce wind energy. That is the reason why towers of wind turbines have grown and grown.

Building tall towers is possible. But it’s expensive. If you don’t believe me, try buying a penthouse on the top of a tall tower.

Currently, wind turbines towers are on average around 100 meters / 300 feet tall and max out at 150 meters / 450 feet. That is already pretty high. I could not afford a penthouse there.

Wind Drones don’t need tall towers to reach high altitudes. All they need is a longer tether.

Let’s see what doubling altitude from wind turbine height of 100 m / 300 feet to 200 m /600 feet brings in terms of wind energy. This is the picture for Germany:

Good wind sites (> 350 W/m²) in Germany at 100 meters / 300 feet and 200 meters / 600 feet altitude © IRENA: Global Atlas, Map data: DTU 2015, OpenStreetMap contributors

At wind turbine height only the coastal areas of Germany are windy enough to be good wind sites (green to brown color). At 200 meters / 600 feet almost all of Germany becomes a good wind site.

It is not just Germany: Google calculated that less than 16% of all the United States is suitable for energy production with wind turbines. For Wind Drones this figure more than quadruples to 66%. Pretty much any site can be used.

And if we go higher at an already good wind site? Let’s see, this is wind power above London:

Wind speed (grey line) and wind power (blue columns) above London, data: University of Reading, UK

The wind power (blue columns) within reach of Wind Drones at 500 meters / 1500 feet is 4 times stronger than at wind turbine height of 120 meters / 360 feet. That high above London the wind is stronger than at the best wind parks of the world, including all offshore wind parks.

The strong and steady high altitude winds also help answering the one big question for renewables: intermittency. The question is: what happens if the wind doesn’t blow and the sun doesn’t shine?

This is much less of an issue if the wind blows most of the time, which is the case at higher altitude. Wind Drones can produce 50% to 100% more energy than wind turbines with the same power, simply because they don’t stay idle and produce at full power for most of the time. Because they solve the intermittency problem, Bill Gates called them the possible “magic solution” for our climate crisis.

Oh, and Wind Drones will be cheaper to build than wind turbines, too.

Why?

It is just cheaper to build a light, flying wing on a tether than the massive tower, blades and foundation of a wind turbine which are made of hundreds of tons of steel, laminate and concrete. A Wind Drone needs 90% less material than a wind turbine with the same rated power. Remember building the tower? We can replace that by a tether that is 2,5 centimeters / 1 inch thick. You do the math.

So, let’s recap: Wind Drones can be built on low-wind sites, produce more energy on high-wind sites, provide more reliable power and also cost less than wind turbines.

Sounds a little too good to be true? If it was really that great, wouldn’t everybody rush to build them?

Yes, and they do: dozens of startups worldwide are building Wind Drones. And corporates including Softbank, 3M, ABB, Honeywell, E.ON, Shell, and others have invested.

Institutions that invested in Airborne Wind Energy research or startups

The biggest investor by far is Google/Alphabet. Its project Makani is also the most advanced player in the field that is most often called Airborne Wind Energy. Google Makani presented a working prototype of their “energy kite” in 2013. They recently completed their first scaled-up product, the M600 with a wingspan of 25 meters / 85 feet and an output of 600 kW. It is currently being tested and will be installed in Hawaii.

Google Makani M600 Wind Drone Prototype © Alphabet [X]

So how big is the potential for this technology? The environmental impact cannot be overestimated. Airborne Wind Energy could become the cheapest, most widely available and most reliable source of renewable energy.

And the business case? Let’s see, we will get rid of fossil fuels in the next 20 to 30 years and renewables will take over. The USD 5 to 10 trillion energy market is awaiting its complete makeover. The only renewables that are available on the required scale are solar and wind. And when it comes to wind energy it is either building towers or flying drones. You do the math.

Drones will soon become part of our daily life. They will power the world, too.

Google Makani energy kite prototype in flight