At the altitude of 800 meters, air has an average speed of 7,6 meters/second with a pressure equal to m1,14 Kg/cubic metre, an altitude sail expresses a power of 210 watt /square metre of surface.

The surface of the balloon is added to the surface of the wing and it contributes to increase the power of the push, but this does not enter into the calculation as it is used for the against the wind dragging of the other balloon with same dimensions.

The wing of the balloon has a surface equal to 200 square metres (similar to the one used by cargo ships with Ms Beluga Skysails) nd therefore it is able to generate a power of 50 Kw that, on yearly base, represents a value of 438 Mw/h .

Considering a 92% efficiency of electric generator on ground, the power on yearly base reaches a value of 400 Mw/h corresponding to 100 tons of oil used in a traditional thermoelectric plant and bringing in atmosphere 280 tons of CO2.

A wing of 200 square metres has a total weight of 320 Kg, while 800 linear metres of Kevlar cable (diameter 30 mm), able to support a traction of 40 tons, has a total weight of 640 Kgs; adding 40 Kgs for the wings opening and closing servomechanism, a total weight of 1000 Kgs is reached.

To be able to support a weight of one ton at an altitude of 800 metres, 12 meters diameter aerostatic balloons are sufficient.