The SPP-30 is highly efficient (92%), and resistant to normal environmental stresses including 1” hail.  These solar water heaters and controllers provide up to 40,000 Btu’s per day per panel.  Each panel can heat 50 gallons of water to 150 degrees on a sunny day.  These high efficiency panels collect energy even on cloudy days with typical collections of 13,000 to 23,000 Btu’s.  A two panel system provides sufficient hot water for a typical family of four.  We estimate that energy savings will pay for the system in less than 5 years, with a maximum payback time of 10 years.  These estimates assume a hot water usage of ~100 gallons per day, gas or propane prices using 2008-9 heating season, and 5% inflation for fuel prices.