A solar water heating system won't eliminate the need for a separate water heater. This type of system is often referred to as "solar thermal."
The most common type of solar thermal system is closed-loop like the one shown in the illustration. An antifreeze solution circulates between a solar collector and a heat exchanger located in a tank-type water heater.
When the antifreeze in the collector reaches a certain temperature, it's pumped through the heat exchanger to heat the water in the tank. When solar heat is limited or unavailable, electric heating elements take over. A solar water-heating system is a fairly expensive upgrade, but it can be worthwhile if you have strong sun exposure and plan to stay in your house for the next eight to 10 years.
Due to our lack of sunny days, the Cleveland area isn't as suited for solar units as other areas of the country. Be sure to evaluate your application's return on investment before investing in a solar installation.