arigram said:
If I manage to earn enough to rebuilt my grandfather's house
and go live in it, I would have liked to build an environment
friendly self-supporting system as to create art and live with
as less possible damage to our planet.
It's possible, but currently a bit on the expensive side. There are also a lot of caveats. For instance, if retrofitting an existing house, the ideal situation is to have a big south-facing roof with an angle that's not too far from the ideal for solar paneling. (That ideal angle varies with your latitude.) If your house, like mine, has a roof that faces east and west rather than north and south, each side will only catch the sun for half the day, which either greatly reduces the time during which the panels can work or doubles the cost (since if you put panels on both sides).
There are other options, but they're also expensive and are not always practical. Small wind turbines work in windy climates, for instance. (I've got a friend who has one of these.) I've even heard of small hydroelectric generators, if your property is on a river or by the sea.
The good news is that the cost of all of these devices is dropping and efficiencies are increasing. With any luck their costs will drop enough for their popularity to go up before too long.