Page 45 - Industrial Plants 2014

Energy Savings for Offshore

Drilling Units Using LEDs

Nuova ASP technical illumination study for drilling infrastructures

Kim Fumagalli
R&D Manager, Nuova ASP

o better understand how it is possible
to achieve energy savings it is important
to firstly analyse different lighting
sources. All lamps currently on the
market can be placed, in accordance
T with the manner in which the light is
generated, into two major categories:
• incandescence: composed of a tungsten filament
which becomes incandescent and emits a certain
amount of visible radiation (light) when an electric
current runs through it;
• electrical discharge in gases: they emit light
through a discharge generated inside a gas. In materials to produce photons from the recombination Fig. 2 - Lighting
particular, among other categories, discharge of electron-hole pairs. When subjected to a direct efficiency trends over
light sources include traditional tubular fluorescent voltage, the electrons of the semiconductor’s time for the most
lamps (commonly, but erroneously, known as conduction band recombine with holes in the valence common types of
lamps
neon lamps) and compact lamps [1]. band, releasing enough energy to produce photons.
Due to the thinness of the LED chip, a reasonable
In addition to these two large categories of sources, number of these photons leave the chip and are
the new LED light power sources (figure 1) have emitted as light [2].
become more widespread in recent years. The following are the main characteristics that need to
LED uses the optical properties of semiconductor be considered for the use of light sources [2]:
• life-cycle: the duration of a lamp is equal to the
period of time that elapses between switching it
on and the moment the luminous flux produced is
equal to 70% of the initial value. A LED has a
longer life-cycle (˜30,000 hours) than any other
lamp: this regards both fluorescent (˜10,000
hours) and gas discharge (˜12,000 hours) lamps;
• lighting efficiency: figure 2 shows the figures
regarding the luminous efficiency trends of
different types of lamps used in the lighting
industry. The graph in figure 2 shows that the
luminous efficiency value of a white LED lamp
(120 lm/W) is slightly higher than that of a
Fig. 1 - Power LED fluorescent lamp;

IndustrIal Plants - May 2014
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