[Exeric]

I think you answered your own question about paying that price for 30 year old panels. But that's far from the end of the story. You need to do your homework before deciding between solar hot water and solar PV. A lot of us (well... me) think your best bet is PV since you live in cold Minnesota. Even if you are snowed in on a cold winter day and are getting zero solar energy to speak of, you can still use the banked credits from the PV power from spring, summer, and fall to subsidize the shortfalls in solar energy you will experience in winter. That's a big deal.

The alternative is to get an enormous solar hot water system that still might not meet all your heating needs in winter. Then you would have this similarly enormous supplus of hot water in spring, summer, and fall that you couldn't use and would just be throwing away. Not very economic compared to a correctly oriented and sized solar PV system. I'm speaking just for a primarlily heating climate like you live in. This wouldn't necessarily be true for a mixed climate.