I live in New York state and we're doing an extensive remodel. We're installing a 6.0kw solar electric system and would also like to do a solar thermal system. We can choose the kind of water heater to go with our solar thermal system, and have been told I have two choices: a tankless system that works along side the solar thermal company's preheat tank OR a standard water heater that works alongside the company's preheat tank. I'm wondering which option is better, and if tankless, if it's better to go with a gas or electric. Also, I understand that if our water is too hard, a tankless system doesn't work well.
Any information and thoughts on this would be great. Thanks.