Converting from a Propane furnace to Zoned Electric Heating

A customer gave us data about their savings from converting their entire house to electric comfort heat (every room, controlled to only heat the rooms being used, when they are using them.)  They have an electric dryer, propane water heater, propane range and central air conditioning.  They are a family of 6 with a ranch house in Lower Michigan with 1,375 square feet on the main level.

06/2007-05/2008 bills:
Electric $1,002 @ 12 cents kwh
Propane $1,455 @ $1.92 per Gallon
Total $2,457

06/2008-05/2009 bills:
Electric $990 @ 12 cents kwh
Propane $1,883 @ $2.07 per Gallon
Total $2,873

The electric heat was installed in late October of 2009 at a cost of $780, which was paid for by the savings in the first year:

06/2009-05/2010 bills:
Electric $1,357 @ 12 cents kwh
Propane $703 @ $2.57 per Gallon
Total $2,060

06/2010-05/2011 bills:
Electric $1,808 @ 12 cents kwh
Propane $811 @ $2.00 per Gallon
Total $2,619

The customer estimates that with the old system, the total bills would now be up to $3,100 because the family has grown from 3 to 6 since 2007.  A savings of $500 per year is sustained now. The customer is also considering future advances in wind power, fuel cells and solar power to supply the house with free electricity to power the heaters, etc.