At the Western Power Head Office and the Office of Energy in Perth, Western Australia, retrofits reduced lighting energy consumption by up to 50% while, at the same time, increasing lighting levels and improving color rendition. Both retrofits made use of low cost white power-coated reflectors rather than more common and more expensive specular reflectors.
A
trial was conducted using white powder-coated reflectors and single
tri-phosphor tubes to replace the existing double and triple fluorescent tubes.
The trial achieved a 30% reduction in lighting energy consumption and a 37%
improvement in lighting levels. Other options explored were perimeter dimming,
ultra low brightness parabolic diffusers and film-coated silver reflectors; all
exceeded a three-year payback period.
At
Western Power, energy savings were 391,600 kWh/year with lighting levels
increasing around 37%. They had a simple payback period of 11.8 months with a
cost of $32,000 and energy savings of $32,400/year.
At
the Office of Energy, standard ballasts were replaced with more efficient, low
loss ballasts, decreasing ballast losses from 19W for two standard ballasts, to
5W for the single, low loss ballast (for one tri-phosphor tube instead of two
fluorescent tubes). They had a simple payback period of 2.7 years with a cost
of $23,000 and energy savings of $8,100/year.