When she told me about it, I started thinking of different things you could add to your house to make it environmentally friendly, or self-sustainable.
I thought of having a rainwater cistern connected to your gutter system that you could use for your bath-, toilet- and dishwater.
Got a little silly and thought up a dishwashing machine, whose water pump and washing tower were powered by a connected exercise bike - not only energy-independent, but it would force you to exercise too, unless you washed the dishes by hand.

Anyway, I thought it would be cool to see what kind of things people could come up with. There aren't any limits, make it as elaborate as you like, as long as it's possible to use in a normal-sized home without having tons of land.
What could you think of to help make a home more efficient and/or eco-friendly?
