i doubt it needs to be, we dont have to do it their way, we have typical stoner 'outside the box' thinking. whatever the exact temprature of our exhaust air, there is energy to be had and more than one way to harvest it. the spirit of the device is here the best tech to use in our enviroment is probably already possible, its just needs a eureka moment to appear...i say there will be something feasible to us by 2015.