According to this [1], the 2015-16 estimated average residential winter heating bills for a propane user ( the highest ) was $2,569. The cost of this system is

According to this [1], the 2015-16 estimated average residential winter heating bills for a propane user ( the highest ) was $2,569. The cost of this system is approximately equivalent to 7.8 years of heating costs. If this system saved 50% on the bill then it breakeven is about 15 years out. These numbers aren't too far from solar historically, if I recall correctly. [1] http://www.mass.gov/eea/energy-utilities-clean-tech/misc/household-heating-costs.html http://www.mass.gov/eea/energy-utilities-clean-tech/misc/hou... edit: these numbers were for Massachusetts specifically