From Incandescent lamps to leds: Three Revolutions in Lighting

Since humans learned to make fire by rubbing wood together, every breakthrough in lighting technology has profoundly changed the course of society. From incandescent lamps to leds, this technological innovation spanning a century has not only illuminated the darkness but also become a significant driving force for global sustainable development.

The First Revolution: Incandescent lamp - the dawn of electric lighting
In 1879, Edison successfully improved the carbonized cotton filament incandescent lamp, ushering in the era of electric lighting. Incandescent lamps emit light by heating tungsten filaments with electric current, but their energy efficiency is extremely low. Only 12% to 18% of the electrical energy is converted into light energy, and the rest is dissipated as heat energy. Moreover, their lifespan is less than 1,000 hours. Although halogen lamps were subsequently improved (in 1959), which extended their lifespan and increased their brightness, the problem of high energy consumption remained unsolved. Incandescent lamps laid the foundation for modern electric lighting, but their inefficient nature gave rise to the demand for subsequent technological innovations.

The Second Revolution: Fluorescent Lamps - An Initial Attempt at Energy Conservation and Environmental Protection
In the middle of the 20th century, fluorescent lamps achieved higher luminous efficiency (about 60-100 lumens per watt) and longer lifespan (15,000 hours) than incandescent lamps by virtue of electronic ballasts and trichrochrome phosphor technology. It generates ultraviolet rays by exciting mercury vapor with an electric current, which are then converted into visible light by phosphor, significantly reducing energy consumption. Mercury pollution, stroboscopic problems and the ceiling of luminous efficacy (up to approximately 103 lumens per watt) make it difficult to meet higher environmental protection standards.

The Third Revolution: LED - The Comprehensive Rise of Semiconductor Lighting
1. Mixing of blue LED and phosphor: In 1996, Nichia Chemical Corporation of Japan used GaN blue LED to excite YAG phosphor, achieving the first high-efficiency white LED for the first time. The luminous efficacy exceeded 80 lumens per watt and the lifespan exceeded 50,000 hours.
2. Exploration of Ultraviolet LED: By using ultraviolet leds to excite multi-color phosphors, the color rendering and luminous efficiency are further enhanced, laying the foundation for smart lighting.
3. Material and process innovation: The application of semiconductor materials such as monocrystalline silicon and gallium nitride (GaN) has driven the luminous efficacy of leds towards 150 lumens per watt.

Advantages of LED:
Ultra-high energy efficiency: The conversion rate of electricity exceeds 20%, and the energy consumption is only 1/10 of that of incandescent lamps.
Environmentally friendly and pollution-free: Mercury-free, with a recyclability rate of up to 95%, in line with the carbon neutrality goal.
Intelligent and controllable: Supports dimming, color temperature adjustment and iot linkage, empowering smart cities and homes.
As a practitioner of LED technology innovation, Yinshi International Co., Ltd. is committed to promoting the "solar energy as a service" model and empowering the global energy transition through efficient photovoltaic solutions. From home rooftops to smart cities, we use technology as our pen to paint a green future.