An Energy Efficient home should engage all of the principles of a Solar Passive home with the addition of energy producing or energy saving devices. For example solar power system, heat pumps or solar hot water systems will all contribute to lowering the homes reliance on the mains supply ultimately reducing its carbon footprint.
Simply put, an energy efficient home is one that uses minimal energy to run. In that regard the home uses natural resources such as the sun and wind to warm the home, provide power, hot water and so on. We are very lucky in Perth as we have plenty of beautiful sunshine all year round and in summer great afternoon and evening breezes. It is also very fortunate that our sun shines in from the north and our summer breezes blow in from a southerly direction. As a designer you could not ask for better conditions to be able to design a home that requires minimal energy to run.