Are you looking for a way to bond with your neighbours? Buy a hot air balloon and generate energy for all your new friends with the balloon engine. Ian Edmonds’ balloon engine traps solar energy in a greenhouse and inflates a giant balloon with the heated air. The balloon pulls a earthbound tether while it rises, spinning a generator to generate electricity. Once the balloon has ascended 3 kilometers it automatically release its air to lose buoyancy. In the descent less energy is needed to pull the balloon back down again, resulting in a net power gain. Edmonds estimates the average power output on 50kW for a commercially available balloon (with a volume of 45,000 cubic metres, equivalent to a sphere of diameter 44m). He predicts that the costs of his balloon engine par with that of wind power. That would be great for sunny places where the wind rarely blows.
Via: NewScientist.com
Link to more information and the concept of operation: Balloon Engine
