With the data posted these are very well worth looking into. Storage or larger volume of DHW is a benefit, where weather might be inconsistent. Also using just one small panel to recover 100 or more gallons would ensure enough reserve on low output days. But with the data it seems the panels make some serious water at some low outdoor temps. I like it, just would like to know more specs to size and calculate options. Thanks Greg for sharing.
Super store heaters are awesome, quote one on every job. It's the last heater you'll ever need to buy. I see their 30 tube collectors do 7-9 million btu/year output. Save a lot of cords of wood right there. HTP evac panels started at $2375 , and there is a 30% fed tax credit with no limits for solar water heater systems. Expires Dec. 2016. They have some output charts and 10 year warranty details.