Is it possible to use solar energy to power a tankless water heater?

I am assuming a gas fired unit. Yes you can some don't require electricity or run on batteries, one took two D cells for controls and igniter. I would look for one that doesn’t need power before I started looking for a solar option. If you do go with a 120v unit you would likely need a 1000w inverter ($150), deep cycle marine battery ($100), charge controller ($100) and a depending on location and power needed solar panels from 80 to 240 watts ($400-$1300).

We are in AZ near Casa Grande with a off grid 3500 watt system.

 

I just installed a 19 gallon, 110 volt water heater from Lowes and it works well for the two of us.  We plug it in betwen 10 and 2 on non cloudy days and it works very well on a limited basis.  Base cost is 215 bucks from lowes.