LED, simply understood, is a semiconductor light-emitting diode, which is the most advanced solid-state lighting technology in the world. LED lights are not the old face of filament and bulb, but a solid-state light source using semiconductor wafers as materials. It uses the movement of electrons to emit light, directly converting electrical energy into light energy. Therefore, the power consumption of the LED is lower and the service life is higher. When the general high-quality energy-saving lamps can be used for about 1 year and can recover the cost, the maintenance cost of high-power LED light sources is low, and the return on one-time investment is more obvious.
Although most energy-saving lamps are more energy-saving than incandescent lamps, they are essentially fluorescent lamps. They emit light by irradiating rare earth tricolor phosphors through low-pressure mercury vapor discharge. At present, they can only be made into double-ended slender tubes. Moreover, the mercury contained in many energy-saving lamps is harmful to the environment. If the lamps are discarded at will, it is easy to save energy and not protect the environment. Semiconductor solid-state light sources such as LEDs are fundamentally different from fluorescent lamps in terms of process. Semiconductor lighting uses cold light sources, which do not need to be inflated, glass shells, or mercury added. It can be described as the whole process from production to use to scrap No pollution. In addition, LED lighting also has the characteristics of good color rendering, no flicker, and soft light.
In order to achieve the goal of energy saving, foreign countries have issued many policies and regulations to encourage the production and use of energy-saving lamps. It is understood that the latest energy law passed by the US Congress has set a timetable for the elimination of traditional light bulbs. At present, incandescent lamps are no longer sold in the EU market. EU countries not only compensate companies that develop low-cost, long-life energy-saving lamps , and also compensate families with difficulties in purchasing energy-saving lamps. The efficiency of lamps developed based on LED lighting technology is expected to increase by more than 1 to 2 times in the next 10 years.
The performance of a light source, known as energy efficiency, can be measured by the ratio of its power to the brightness it produces, expressed in lumens per watt (lm/W). An ordinary Philips 60W frosted incandescent lamp can produce 890 lumens of brightness, so the energy efficiency of this light source is 15.8lm/W. Depending on the type of bulb package, the actual performance of the lighting fixture may be significantly reduced. For example, if a standard incandescent lamp is placed in a recessed light source and a reflector is used to reflect the light source, we end up with only 50% lighting efficiency due to the loss of the reflector. The energy efficiency of the entire lighting device becomes 7.5lm/W.
We often see some LED manufacturers claim to have further improved the lm/W performance of LED lighting sources. For example, the research plan formulated by the DOE is to increase the efficiency of SSL light sources in the commercial lighting field from the current 30lm/W to more than 150lm/W. Based on the current draft ENERGY STAR program for SSL recessed lighting fixtures, we can calculate the overall energy efficiency of an SLL lighting fixture constructed from existing components, for lighting with an aperture slightly larger than 4 inches and a correlated color temperature (CCT) of 3000K device, it has a minimum brightness of 500lm and a minimum light source efficiency of 35 lumens per watt.
The performance of cool white LEDs has doubled in the past two years. If there is a similar improvement in the energy efficiency of warm white LEDs, we could see warm white LEDs with 80lm/W in the near future.
The selection of isolated driver ICs also plays an important role in improving the energy efficiency of the entire lighting installation. Right now it’s a trade-off between price and performance. The price of linear driver IC is the lowest, but its energy efficiency is in the range of 50% to 60%. The energy efficiency of the switching driver IC is the highest, generally between 80% and 85%. To achieve higher energy efficiency, more complex circuits are required, so the cost of the driver IC is higher.