The coal-to-gas switching price is the allowance price at which a given gas plant and a given coal plant have the same marginal cost:
उदाहरण
Example 7.8 (Where gas beats coal)
With gas at of fuel, coal at , efficiencies of 55% and 40%, and emission factors of 0.202 and 0.341 tonnes per MWh of fuel (illustrative round numbers), a MWh of electricity emits 0.367 t from gas and 0.853 t from coal, and the switching price is . At and power at the clean spark spread is and the clean dark spread : gas is just ahead.