Fluorescent gains
POOR power quality of lighting equipments has not yet become a great problem. But it has to be managed in the future. Compact fluorescent lamps (CFL) can provide high-quality light at a low power consumption level.
In 1991, a major environmental group in Sweden attacked the programmes sponsored by electric companies that promoted CFLS. The group claimed that a screw-based CFL consumes much more energy than what its rated power indicates, owing to its low power factor (PF). However, they had built their case around a misunderstanding.
'j, A 25 W CFL can replace a 100 w lamp with an equivalent light output. The 25w CFL with a typical PF of 0.5, will have an apparent power of 50 volt- amperes (VA). Since voltage multiplied byl. ampere normally equals watt, it would mean that the active power consumption of such lamps is 50 W. Although it is true that 50 VA is equivalent to 50 w of generating and distribution capacity, only the rated active power of 25 w will be consumed when the lamp is used. Thus the CFL with a PF of 0.5 will free about half rather than three quarters of the generating capacity. However, the lamp will still save about three quarters of the energy used for lighting.
The low power factor of conventional (electromagnetic) CFLS is due to the fact that their voltage and current are not in phase. Capacitors can be installed either on transformer substations or on the premises of large end-users to improve the power factor. If an electric company has an underground distribution network, the capacitance of the system itself will, to some degree, compensate for the energy lost due to the phase shift in CFLS. In fact, most electric companies charge large customers extra due to a low PF, hence, improving it is in their interest.