STEM与日常科技·英语30篇（2）

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为什么LED灯比白炽灯更省电

LEDs produce light through electroluminescence, where electrons release photons directly in a semiconductor.
White incandescent bulbs heat a tungsten filament until it glows, wasting over ninety percent as heat.
Because LEDs avoid thermal radiation, they convert nearly ninety percent of energy into visible light.
A typical LED uses only eight watts to match the brightness of a sixty-watt incandescent bulb.
Their solid-state design lacks fragile filaments, making them far more durable and efficient.
Heat sinks manage the small amount of waste heat LEDs do generate near the chip.
Unlike older bulbs, LEDs dim smoothly without changing color temperature or efficiency.
They last twenty-five times longer, reducing both energy use and replacement frequency.
Even in cold environments, LEDs start instantly and maintain full output without power surges.
This fundamental physics difference explains why cities worldwide are switching streetlights to LED arrays.