Comparing Energy Costs

Electricity

Water/Air HP

(COP 3)

(Cents/kWh)

Fuel Oil

Regular

(60% Eff.)

($/gal.)

Propane

Regular

(92% Eff.)

($/gal.)

Natural Gas

Regular

(75% Eff.)

($/therm.)

Natural Gas

Super Efficient

(92%) Eff.)

($/therm.)

Geothermal or Ground-Source heat Pump 300% Efficient
.0625 0.51 0.51 0.45 0.56
Air-to-Air Heat Pump 200% Efficient
.0625 0.76 0.77 0.68 0.84
Electric Resistance 100% Efficient
.0625 1.53 1.54 1.37 1.68

 

Fuel Btu Heat Content Annual Season Operating Efficency
Electricity  3,413  Btu/kWh    100%, 200%, 300%
#2 Fuel Oil   140,000  Btu/gallon 60%
Propane  91,600 Btu/gallon 92%
Natural Gas 100,000 Btu/thermal  75%, 92%
Wood   16,000,000 Btu/ton  60%


Formulas:
Alternate fuel price to electric rate conversion formula:
            (Fuel Price) / (Fuel Eff.) x (3413 x Elec. Eff.) / (BTU Content) = Electric Rate
           
            Example of $1.48/gallon propane to electricity with a super-efficient furnace:
                        (1.48) / (0.9) x (3413x100) / (91,600) = 6 cents per kWh
 
Electricity rate to alternate fuel price conversion formula:
            (Electric Rate) x (Fuel Eff.) x (Btu Content)  /(3413xElec. Eff.) = Fuel Price
 
            Example of 6.4 cents/kWh Electric Rate to #2 Fuel Oil with a regular furnace:
                        (6) x (0.6) x (140,000) / (3413x100) = $1.47 per gallon