When Interoil Corporation began to build a new staff housing village at their refinery complex outside of Port Moresby in Papua New Guinea, they knew that street light was going to be a challenge. Not only was the local electricity grid unreliable, it was also difficult to access. Something other than conventionally powered street lighting was required to do the job.
Interoil had previously used outdoor solar lights to illuminate remote work areas and surge ponds with great success and the simplicity of installing those lights plus the reliability that had been demonstrated, directed Interoil to consider solar street lighting for the staff accommodation village. Interoil went back to Orion Solar in Australia, the company which had supplied the previous lighting for the remote work areas.
Orion Solar proposed 16 solar street light including LEDway 40 lighting fixtures, pole top mounted solar engines, along with the poles and foundation cages. The lights were programmed to switch on automatically at dusk and off at dawn and stay on at the full intensity all night. An option would have been to have the lights dim at a specific number of hours after dusk and return to full brightness 2 hours before dawn. All of the controls, batteries, solar panel and lighting fixture are contained in a pole top enclosure making them vandal resistant and less affected by heat. Once the poles were installed, setting up the lights was a simple matter taking less than 30 minutes per light.
Solar street lights generally require very little maintenance with the batteries usually lasting at least 5 years. Other than that, the only maintenance requirements would be to ensure that the solar panels are kept clean. There are several products available to deter birds from landing on the panels and from fouling the solar cells.
Solar street illumination are customised for a given application. This takes into account the amount of sunlight which can be received based upon geographic position and the required number of days of autonomy, this being the days when the lights will operate at full strength even when sunlight is unavailable. It is also worth noting that solar street lights do not require full sunlight in order to charge their batteries. A lower level of charge will be achieved even on cloudy days.
The current generation of solar street lighting can match the levels of illumination provided by hard wired lighting fixtures all the way up to highway level lighting. No longer are solar street lights limited to low level lighting applications. The lighting distribution from solar street lights can be selected by the user and in the case of the accommodation village, the light would be directed along the roadway and not into the windows of the accommodation units. Since most solar street lights use LEDs in the lighting fixture, energy wastage is minimalised and the lights are what is considered "dark sky friendly". That means that no illumination is wasted by shining into the sky and causing a glow around the whole village.
In summary, Interoil achieved the lighting they required for the accommodation village at a lower cost than would have been the case with conventional lighting and they did so with reliability and availability of the lighting being far more satisfactory than could be achieved off the local electricity grid.
