Combustion efficiency refers to how effectively a fuel is converted into energy during the combustion process. It is measured by the amount of useful energy produced compared to the total energy content of the fuel. Higher combustion efficiency means more energy is extracted from the fuel, leading to reduced waste and lower emissions. Factors affecting combustion efficiency include the type of fuel, the design of the combustion system, and the operating conditions. For example, natural gas typically has higher combustion efficiency than coal due to its cleaner burning properties. Improving combustion efficiency can lead to cost savings and environmental benefits.