“A greenhouse traps solar energy, providing hot air to fill the balloon. As the balloon rises, it pulls a tether, which turns a generator on the ground.”
Balloon power should be cost competitive with wind turbines and other solar energy methods.
Australian inventor Ian Edmonds lists the balloon engine’s advantages at his own balloon engine page:
“The marked cost difference between an updraft tower engine and a balloon engine is due to three factors. (1) A tower is a steel or concrete structural component. The material and assembly cost is high and increases rapidly with height. A balloon envelope is formed from thin, relatively low cost material which is essentially self supporting in operation. (2) The balloon engine operates at about three times higher efficiency than an equivalent output tower engine therefore the glazed collector can be much smaller in size. (3) The balloon engine utilizes components sourced from well established industries. Namely the recreational hot air ballooning industry, the rope industry and it utilizes a high torque, low frequency drive train between the windlass and generator similar to that used by wind turbines. Much of the drive train technology for wind turbines in the 10 kW to 1 MW range should be directly transferable to balloon engines in the same power range.”