When buying an LED lamp or luminaire one of the most important things to consider is the products efficiency, or the ability of the product to convert electrical energy into visible light. Lighting efficiency is represented as lumens (amount of light emitted or luminous flux) per watt (power consumed) or lm/w. The higher this figure is, the more energy efficient the product is.
With older lighting technologies such as incandescent, halogen and HID it was safe to assume that the higher the wattage was; the more light would be emitted. This is because the technologies’ efficiency of converting energy into light was similar across various products using the same technology.
LED lighting is different because LED lamps and luminaires can have vastly different efficiencies depending on the LED and driver components used by the manufacturer. Today, the variance can be from <80lm/w on low end products to 160lm/w+ on high end quality luminaires. That is a massive difference! A quality LED product can be twice as efficient as a poor quality LED.
Ie: Economy 100W 80lm/w LED Floodlight = 8000lm
Quality 100W 160lm/w LED Floodlight = 16000lm
As you can see, the economy floodlight only offers half the light output. The same lumen output could be achieved by a quality 50W 160lm/w floodlight.
Therefore, the wattage of LED lights should not be used as criteria for making a buying decision. ALWAYS look at the lumen output and the efficiency of the product to compare between different options and make an informed decision. A quality, highly efficient LED luminaire will provide more light and consume less power than an inefficient product and is, therefore, a much better option for customers.
Important note: The terms efficiency and efficacy are similar and often used interchangeably by suppliers. However, it is very important to distinguish if the lumen output in the product specifications indicates the efficiency of the LED Chip (sometimes stated as Raw Lumens, Lumens at Source or LED Luminous Flux) or the efficiency of the Complete Luminaire (sometimes referred to as Useful Lumens - this is the lumen output of the LEDs less the losses from the driver, reflector, lenses etc.). The efficiency of the complete luminaire is far more useful as this provides the actual figure of the lumens being provided out of the fixture.