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