Gas at $0.80/therm (cheap gas market, e.g., Texas or Oklahoma), 95% AFUE - Gas cost per BTU: $0.80 ÷ (0.95 × 100,000) = **$0.0000084/BTU** - Electricity at $0.14/kWh, heat pump COP 2.5 (winter average) - Heat pump cost per BTU: $0.14 ÷ (2.5 × 3,412) = **$0.0000164/BTU** - **Gas wins by a factor of 2