Power factor describes how efficiently an LED driver uses electricity. It is the ratio of the real power that is used to do work and the apparent power that is supplied to the circuit. The power factor can get values in the range from 0 to 1. The closer to 1 the power factor is, the more efficient the driver is. A good power factor is 0.9 or above.
Power factor correction refers to a system of inductors, capacitors or voltage converters that adjust the power factor of electronic devices toward the ideal power factor of 1.0.
How does the generation of reactive power occur? It is caused by certain electronic components in the device, which first require the construction of a magnetic or electric field. This energy is needed to set up and dismantle the fields. This energy can be imagined as a component in the electricity network, which constantly oscillates back and forth between the generator and the electrical loads and is only responsible for maintaining the fields. The energy must nevertheless be generated and the power lines must be correspondingly larger in size. Two types of reactive power are distinguished: the inductive reactive power (magnetic fields caused by coils or transformers) and the capacitive reactive power (electric fields caused by capacitors).
Retrofit LED lamps with their electronic components, like many other household appliances, also belong to the capacitive consumers. This also makes the performance factor relevant to them. It is in most cases between the values 0.5 and 0.9. A higher value according to the above equation stands for a more efficient use of the provided energy. However, the performance factor does not say anything about the quality of a product in terms of life, lighting technology or durability.
Finally, an important piece of information about the power calculation: the power supply system must dimension its net power for the total apparent power, but calculates only the real power, ie the actual consumed power of its devices. The reactive power, on the other hand, is at the expense of the energy supplier.