Most people don't think about alternate power sources until the power goes out. Those who choose to live off-grid can think of nothing else. Let’s face it; most of us need electricity to be able to control the environment where we live and to have conveniences to make life more enjoyable. In emergency situations a lot of people opt for a gasoline powered generator. If you don't have adequate fuel storage you aren't going to run very long before you need to find more. Some alternate power sources don't require fuel. Solar, wind, and microhydro power systems operate from conditions present in your environment. Which system you choose depends on your particular location and available resources. In addition to supplying emergency power they can also off-set your day to day power costs.