May 5, 2014
will the energy saved by bikers not riding cars equal or exceed the energy required to run the wind generators? Seems like a neat trick but not practical.
May 16, 2014
It seems that the tunnels and the associated infrastructure will be very energy and material intensive and hence construction may cause a significant amount of CO2 emissions again. Could exisiting infrastructure such as old unused pipes be converted to be used as bicycle wind tunnels? That would save a lot of material and energy. New built tunnels might be feasible in very specific situations though, e.g. in highly polluted cities. Did you think of a specific location where you would like to see this project being initiated?
Aug 5, 2014
The concept would likely have little impact on GHG emissions but is interesting. The greatest benefits would likely come from reduced obesity and shorter commuting times in congested cities. Pumping air through tubes for bikes would likely be net thermodynamic negative. The air would have significant flow losses and the gain from the bikes would be negligible.