In an integrated design system, ultra-modern buildings can harness multiple energy sources for cooling, heating, electricity and water. When natural heating and cooling is used, together with energy optimized appliances, generating power from natural forces is inexpensive because a much smaller energy system is needed. The design of the home is the key factor in this equation, and aesthetics need not be sacrificed. You can warm a house by capturing the heat form the sun (through south-facing windows), in a massive object such as a tile floor or a wall of water. Adding a green roof helps keep indoor temperatures constant, as do strategically placed trellises or trees. You can capture breezes by creating open floor plans, and by encouraging cross breezes. You can add a ventilation cupola that creates a "thermosiphoning" effect through the house. Some designers use clerestory windows to allow sunlight to penetrate deeply into a house. Manual shutters can be used to close windows from the sun, and insulate the house at night.
Some amounts of supplemental heating and cooling may be needed. If so, you can use natural heating sources like super-efficient wood burning stoves, biomass heaters (corn or wood pellet stoves) or biofuel heaters.