Yes this is our preferred method of heating as it is the most cost effective. You can heat the water by adding a solar pre-heat tank before your existing tank and use your hot water tank to supplement the solar heat (i.e. your existing tank’s heater will kick in when the solar cannot fully supply the demand). This is the most efficient way of heating. Alternatively if you have an electric hot water heater you can add a special solar conversion valve (supplied by GALEX) .