Please check out Tenkiv solar energy company. They use a more cutting edge technology, making their system work more efficiently.
I will be getting my system installed in October (they are backed up). I have to use a water softener and filter for our St. Louis Park, MN, awful water, but after October I will have distilled water from my Tenkiv system. I am told this system will pay for itself in saved heating costs. Very exciting. Don't have an "x" amount yet, but I think this is a good gamble.