For a home you care about (could be the one you grew up in, the one you live in now, the one you hope to live in in the future, etc...), calculate the cost and benefit of using the following technologies. A google search will turn up a number of calculators, just try to pick one that is somewhat unbiased (a company selling solar panels is going to give you a best-case scenario). Post all 3 of your results to the discussion forum and include anything you are skeptical about.
Off-grid Solar Photovoltaic (this will include storage costs)
Grid-tied Solar Photovoltaic
Solar Water Heating (be sure to include any rebates)
For more information
Here are some energy innovation ideas related to solar energy: