CHALLENGE 4c1c1: Cape Town Rural and Urban Wind Challenge

This is Challenge 4c1c1 from CH4c: Community level circular products and services



Note: All our challenges are collaborative. Skype, email or contact us if you want to work with us in real-time! Let’s make a better world for everyone together!

Cape Town is a very windy city during the winter months (May to August). the author of this challenge experienced this for the first time on June 3, during the first big winter storm.

That there is significant potential energy that can be harvested in is the conclusion of a number of studies. There are, however, many ways to approach harnessing this energy other than standard large wind turbines, which are really not suitable for an urban environment.

One simple but intriguing idea is from physicist Carl Johnson, who proposes a community wind wall design, which his calculations show to be 1/10 the cost of normal wind turbine costs to achieve the same average power. Since the concrete building facades of urban centers already provide walls, is it possible to find areas of wind constriction where a simple vertical axis wind turbine can be installed to harness the increased speed of the wind? The sheer power of the wind through Cape Town’s streets could result in a lot of usable energy. Would it be possible to use the walls of the buildings by adapting additional structures around them to harness urban wind for renewable energy?

Another radical idea is to use pizeo-electric leaves attached to all the buildings. A number of engineers and architects are using this approach for urban wind.


Activity: Global brainstorm session and begin initial design

Explore the possibility of harnessing wind flowing through Cape Town’s urban landscape to generate urban renewable energy.


  • industrial design
  • engineering - hardware, software, mechanical
  • renewable energy - wind physics
  • urban design / planning
  • physics
  • computer simulation and modeling
  • applied mathematics

CH 4c1a:The renewable energy designs of physicist Carl Johnson
Pizeo-electric wind transducers for low speed urban wind
The Swedish Pizeo-electric strawscraper
Flywheel energy storage: Ryerson Centre for Urban Energy
Urban Wind Energy
Compressed Air Energy Storage
ABB urban wind project

This sounds interesting, is there any similar activity this year?

Yes, we are launching the OpenC Cape Town initiative. We are taking a systematic analysis of Cape Town to map out renewable energy to see where the best places for community level renewable energy systems in the city. We want to generate open data for various aspects of industrial metabolism…all open source. We would love to see where all the energy potential is in the city. The same goes for waste flows. Check out our OpenC challenge. Any city can set up a similar challenge and we can pool our resources onto one global geomapped database.