World Changing


We have illustrated how the laws of physics in combination with sensors, chips and smart algorithms can replace the tons of steel and concrete wind turbines are made of. This can make wind drone power cheaper than electricity from fossil fuels. Their ability to harvest stronger winds higher up in the air gives wind drones the potential to provide power where it is needed irrespective of the existing wind resource. Cost-effective electricity made by wind drones could even provide the basis for the clean synthetic fuels of the future. And this fuel could be available at less than today’s oil price.

A lack of wind will no longer be a problem. We have seen how the wind resource dramatically increases by doubling the altitude. But this is only the first humble hop of wind drones into the air. Once these altitudes are mastered, it will be tempting to gradually go higher, until they reach the jet stream at 10 km/33,000 ft. Before, many technical and legal problems will have to be solved. But it will be attempted. The wind resources at this altitude are simply too enticing. The median energy density over New York at this height is more than 10 kW/m² [12] of which about 5 kW/m² can be used [13]. The total energy consumption per person in the US amounts to 10.5 kW. This includes all electricity use, heating, car and aviation fuels, and even industrial energy consumption. This means that harvesting wind in an area of 2 m² (22 sq ft) per person, the size of an open front door, could on average provide all our energy. If 10 wind turbines with today’s dimensions were installed in that altitude over New York, they could have the same rated power as an average nuclear power plant, over 1 GW [14]. High-altitude wind energy is not only an extremely concentrated source of energy, it is also abundant. It can provide about 100 times of today’s global energy consumption [15]. High altitude wind energy could allow us to live a greener lifestyle without the need to reduce our use of energy. For the energy sector this could mean nothing less than finally solving the conflict between economy and ecology.

Burning fossil fuels started the industrial revolution. It enabled the advances of mankind in the last 200 years. Without fossil fuels feeding 7 billion people on this planet would be impossible. But fossil fuels also destroy and pollute nature, poison our cities and homes and cause an ever more dangerous climate change. Furthermore, our reliance on fossil fuels leads to unjustified wealth and power imbalances, to wars over their control and to undemocratic regimes.

When mankind started to burn fossil fuels 200 years ago it made a huge leap forward. When it stops to burn fossil fuels, it will make another big step towards a better world. Drones will help to bring this day much closer than most of us believe today.
 


1. Additional Operations & Maintenance costs are 20% of total costs. Source capital costs breakdown: IRENA International Renewable Energy Agency, Working Paper Renewable Energy Technologies: Cost Analysis Series, Volume 1: Power Sector Issue 5/5 Wind Power, June 2012
2. All data is for the MHI Vestas V164-8WM, currently the largest wind turbine prototype of the world.
3. Calculated for 8 MW power and flight altitude of 250 meters. M. Diehl. Airborne Wind Energy, Airborne Wind Energy: Basic Concepts and Physical Foundations. Springer, 2013.
4. A detailed explanation of the higher efficiency of the wind drone wings is beyond the scope of this article. For an introduction to the physics of wind drones see M. Diehl. Airborne Wind Energy, Airborne Wind Energy: Basic Concepts and Physical Foundations. Springer, 2013.
5. Wind Data source: Christian Geiss, Technical University Chemnitz, Studies on the vertical wind profile in Saxony (Untersuchungen zum vertikalen Windprofil in Sachsen), 2012.
6. A doubling of power output is also roughly expected from average offshore compared to average onshore sites: IRENA International Renewable Energy Agency, Working Paper Renewable Energy Technologies: Cost Analysis Series, Volume 1: Power Sect or Issue 5/5 Wind Power, June 2012.
7. IRENA International Renewable Energy Agency, Working Paper Renewable Energy Technologies: Cost Analysis Series, Volume 1: Power Sect or Issue 5/5 Wind Power, June 2012.
8. Draft Guidance Material 1 (GM1) Standardized European Rules of the Air SERA.3138(a) paragraph (b) in: NPA 2014-09.
9. Global Wind Energy Council, Global Wind Report 2013.
10. International Energy Agency, World Energy Outlook 2013.
11. 0,3% in 2011: Wind 434 TWh, Total Energy Demand: 13.070 Mtoe (= 152,000 TWh), International Energy Agency, World Energy Outlook 2013.
12. C. Archer, K. Caldeira; Global Assessment of High-Altitude Wind Power, Energies 2009, 2(2), 307-319; doi:10.3390/en20200307.
13. The theoretical maximum is the Betz limit 16/27 or 59%. Modern wind turbines are very close to this with efficiencies of about 50%, including losses in generators, drivetrains etc.
14. The Vestas MHI Vestas V164-8WM with a blade lengt of 82m features a swept area of 21,124 sqm. With 10kW/sqm and 50% efficiency, this results in 105 MW per Turbine or over 1 GW for 10 turbines.
15. K. Marvel et al. Geophysical limits to global wind power, Nature Climate Change, Vol. 2 no. 9 September 9, 2012; M. Jacobson and C. Archer. Saturation wind power potential and its implications for wind energy. Proceedings of the National Academy of Sciences, 2012 (doi:10.1073/pnas.1208993109).
 


Udo Zillmann
Udo Zillmann is the founder and managing partner of Daidalos Capital GmbH, a fund management company that specialized in investing in airborne wind energy companies since 2010 and is currently raising its second special airborne wind energy fund. Mr. Zillmann is author of Financing Strategies of AWE Companies in the book Airborne Wind Energy (Springer, 2013) and a regular speaker on airborne wind energy. Mr. Zillmann holds degrees in law and business.


Images: Skywalk From Outside Ledge by Complexsimplellc CC BY 2.5;
Wind turbine near Sweetwater, Texas by Drew Stephens CC BY-SA 2.0;
Top image: Google’s Makani flying wind turbine.