When it comes to solar water heaters, be realistic. They're typically only 30% more efficient than any other form of water heater. Second, don't think that just because you shower in the dark means you'll have to deal with cold water. Water heated by solar power should stay warm for 24 hours.
Solar Power World provides information and tips for the technology, design, development and installation of solar power and its projects.
Check into all of your potential rebates. You know there are rebates, correct? The government (in certain states) has a bunch of ways that they'll reward you for taking the solar energy plunge. And there are also benefits during tax season. Look into them all so you'll get every penny coming back to you.