 Emission intensity is the greenhouse gas emitted over the life of a generator per unit of electricity generated.Of the currently widely used methods of generating electricity the emission intensity of coal and oil is high, as they emit around 1000g of CO2eq for each kWh generated; natural gas is medium emission intensity at around 500g CO2eq per kWh; and all other methods are typically low emission intensity of under 100g per kWh.The emission intensity of coal varies with type and generator technology and exceeds 1200g per kWh in some countries.