Solar water heaters have been around for hundreds of years. For over 50 years people have been using them to heat everything inside and outside the home. Over the years, these solar water heating systems have become much more efficient. If you are located in sunny areas of the country, you should look into buying a solar water system.
You should always have a lease transfer option if you lease the solar energy system versus purchasing it outright. If your home is sold, you will need to have this option handy. If you can transfer it to the new owners, you'll be fine.
If you reside in an area where temperatures drop to freezing, you have to take special care of your solar energy system. Every time the weather gets very cold, you need to turn the system off and drain it. This will help you keep your system working for a much longer time.
Free Hot Water with DIY Solar Batch Water Heater Pt 2.