Hello. This is not a purely gravity design. Imagine scenario: At 50.000 meters there is 0.1% of an Atm. If i close 1000m3 in a sealed box,inside there are about 1.3KG of air. Now i exchange inside thermal energy with 0(1-2-3)°K and i accumulate about 100% of thermal energy of gas. Pression inside of the container falls,tending 0 Pa. I let atmospheric pression act on the container bringing it to 1dm3. All the energy gave by atmosphere is converted in calour and re-put in atmosfere. Now this 1dm3 containere falls till the ground producing 1,3*50000*9,81 J. At the soil we expand container using same enegy we managed to use when the container was compressed. We re-put inside the container all energy extracted with Carnot cycle,to allow air inside container,now 1m3,to become at same temperature and pression of the soil. We created 1,3*50000*9,81 J. :)
I designed an apparathus that works using this method. It is for private sale...if you are interested or know who could be,you will divide with me the prize... you know,i like to dream... (it can produce from 1 to 300 Kw of free energy,day and night)
I think costruction of this machine can be estimated in 10.000 euros,enough to prove that it works... perhaps then we can win the OU prize..