Power (electrical power), indicates the energy quantity that the electrical devices consume unit of time. The unit of power is Watt and represented by W.
Lighting equipment consumes some energy as all electrical devices. This consumes of energy expressed in Watt. The Watt indicates the amount of energy a lamp uses to produce light.
Low power consumption devices which have low watt value spend less energy. However, brightness issue is very important here. Reducing in power consumption may lead derogation of lighting conditions.
A lighting equipment can provide both low power consumption and high light. In other words, two lamps with same lumen value can have a different power consumption than another one. The important issue here is Lumen/watt efficiency. The important thing is how many lumens light is produced for spent 1 W energy.
Especially in commercial buildings, energy consumption due to lighting has a large share of total energy consumption. Therefore, it is important to use energy efficient lighting solutions in such areas.
If we compare today’s technology, we can say that light sources used in the past produce little light according to the amount of energy it consumes. High-efficiency lighting technologies have begun to enter our lives with technological developments.
High power generally means brighter light. However, this is not a correct theorem when compared these different technologies.
In past, watt was used to indicate the light power of a lamp. However, today the light efficiency increasing constantly. Therefore, lumen value becomes important in selection of lighting devices. Costumers should focus on lumen value instead of watt when choosing lighting devices.
First of all, the requirement of lumen value should be determined in a lighting project. After that, the most efficient light source which offered the lowest power consumption with this lumen value must be preferred. LED and energy efficient lamps may offer high lighting performance with low power consumption.
Measuring devices called Wattmeter can be used to measure the power of an electrical device from the mains. These devices show the power consumption in a wide range by measuring voltage and current with high precision. Power supplies with alternating current have its own internal power meter.