Hey, i don't know much about physics but i have heard that gravitational energy is non efficient since it needs a lot of power. So this is what i had in plan.. Average household has 2 to 3 members with each waiting average 50 kilos. You would use their combined weight force to pull up a 1000 kilo weight up in the air 5 meters using a 1:5 lever, two pulleys, wheel and a cabel. About the force applied: 3 times 50 kilos if they stand on the lever, + they could use additional force pulling with their hands a rope that's tied to the ground. The system i am talking about is down on the picture. About the wheel: The levers on the wheel can move in one direction letting the lever on wich force is applied go down and pus the wheel again. Whats the use? So you have two small wind turbines.. two small solar collector.. And you are short of some extra power for your house to be fully independent. Can someone brainstorm this quickly with me, or do the "calc"?