Physics: Why LED Bulbs Dissipate Far Less Energy

Efficiency is the ratio of useful output energy to total input energy, expressed as efficiency = useful output / total input × 100%. In lighting, this ratio reveals why bulb choice matters: an incandescent bulb rated at 60 W converts only 5% of its electrical input into visible light, wasting the rest as heat, while an LED delivering the same light output draws just 8 W. The same illumination, a fraction of the power. That difference scales far beyond a single fitting. Because power is energy transferred per second (P = E/t), each bulb's wattage determines how much electrical energy a household consumes over time. Multiply the saving across millions of homes, and the effect becomes societal: reduced demand on fossil-fuel power stations, lower greenhouse gas emissions such as CO2, and cheaper electricity bills. Efficiency, in other words, is not just a number — it links everyday choices to environmental and economic consequences.