Been living for 2 weeks in Gaia, an ecovillage about 2 hours outside of Buenos Aires, Argentina. They have 50 acres of land, 9 permanent members living there, a range of volunteers and visitors which swell from a few to 40 each day, and a foundation dedicated to developing and teaching permaculture, a system of farming, construction, and placement of sustainably livable and practical environments.
They utilize many technologies to create their utopia. They demonstrate that the principals are largely old and simple, just the knowledge has been lost over time. Some of these technologies include:
*Batteries which provide electricity for the whole community. These are charged by 2 solar panels and three wind generating propellers.
*Hot water showers powered by individual solar panels.
*Metallic reflectors, much like a satellite dish, that boil water by focusing sunlight.
*Woods boxes to trap heat, allowing for food to finish cooking with half of the energy used.
*Dry toilets that separate liquid and solid waste, designed to be emptied, filtered, and converted into fertilizers.
*Houses with walls of made of mud and wood and roofs of thatch and living grass. They keep the space cold during the summer and the warm in during winter. They look like Smurf houses.
*Suaves placed in front of each house. These are basically dry lakes that fill up with water when it rains. They reflect sunlight and heat the house during the winter.
*Gardens, trees, and plants placed in strategic scattered locations (not in long homogenous rows) to be used as food, oils, and natural medicines.
http://www.gaia.org.ar/