The lighting industry generates over $70 billion per year and accounts for 8% of all energy and 22% of all electricity used worldwide. A U.S. Department of Energy study has indicated that switching to SSL lighting could reduce our lighting energy requirements 25% by 2030, which is the equivalent of eliminating 1499 terrawatt hours, or 24 1000MW power plants, and preventing the emission of 246 million metric tonnes of CO2. This significant increase in efficiency could save municipalities, businesses, and homes approximately $15 billion in energy costs.
Are LEDs cost-effective?
The costs of LED lighting products vary widely. Although good-quality LED products currently carry a significant cost premium compared to standard lighting technologies, their costs are declining rapidly. Recent industry roadmapping indicates prices for warm white LED packages have declined by half, from approximately $36 to $18 per thousand lumens (kilolumens, or klm) from 2009 to 2010. Prices are expected to decline significantly, to approximately $2/klm by 2015. It is important to compare total lamp replacement, electricity, and maintenance costs over the expected life of the LED product. Learn more about cost-effectiveness trends.
How long do LEDs last?
Unlike other light sources, LEDs usually don’t “burn out”; instead, they get progressively dimmer over time (a process called lumen depreciation). LED useful life is typically based on the number of operating hours until the LED is emitting 70 percent of its initial light output. Good-quality white LEDs in well-designed fixtures are expected to have a useful life of 30,000 to 50,000 hours. Learn more about lifetime of white LEDs. A typical incandescent lamp lasts about 1,000 hours; a comparable CFL lasts 8,000 to 10,000 hours, and the best linear fluorescent lamps can last more than 30,000 hours.
A primary cause of lumen depreciation is heat generated at the LED junction. LEDs do not emit heat as infrared radiation like other light sources, so the heat must be removed from the device by conduction or convection. Thermal management is arguably the most important aspect of successful LED system design. Learn more about thermal management.