The designers say that the turbine is based on models produced by Hetronix, although the blades are obviously designed to rotate about a central axis within the cylinder housing. Much of the T-box would be below ground level with only the vent showing, and even though the wind produced by passing trains may only come in short bursts, installing them along a busy route should result in a decent amount of energy being produced.
Of course, keeping these babies clean and safe could be a problem. In addition to the dust and debris kicked up as the train speeds along or grime and grease deposits escaping from underneath, protecting such shiny boxes from the destructive hands of vandals could prove somewhat tiresome.