Loadshedding has communities, the private sector and even government municipalities searching for affordable and reliable solutions. For municipalities, the most important areas of concern are public street lighting and public spaces such as recreational parks.
Until now, solar offerings have been pushed aside due to the size and weight of the panels and battery packs. “Due to technological advances in the field of energy storage and generation recently, solar street lights have been making head way into the public eye with great success,” explains Ian Marais, Systems Engineer at Genlux. But is there a reason that lighting using solar high mast solutions has seen little to no adoption in the same period?
During the design phase of the lighting system, it is important to consider the weight of the solar panels, batteries and extra bracketry, as well as the efficiency of the solar panels. “Even more important, is the capacity of the existing high masts sufficient?” asks Marais. Public lighting design in South Africa is governed by the lighting standard SANS 10389-1, which specifies the minimum average maintained illuminance for different types of areas. By reducing the total high mast floodlight power to 40%, from 1,500W to 600W, the solar panels can be smaller and the batteries lighter. This increasing the feasibility of a mechanically sound high mast.
To ensure that the batteries are small enough to be charged and will not overburden the mast, the 600W LED floodlight power is further reduced by utilising light dimming profiles to 300W during the night cycle. “The cost of this design choice, by abandoning the specifications as prescribed in the SANS standard, is that not nearly enough light reaches the ground,” explains Marais, who adds, “Spacing and luminance requirements are designed to ensure a good level of uniformity between masts. Having light only illuminating the base of the mast serves no practical purpose.”
Solar high mast lighting solutions are an attractive option for the upliftment of informal settlements and townships that are home to some of South Africa’s poorest communities, which are estimated to be made up of 90% black South Africans. Should the deployment of solar power high mast with poor lighting performance be realised, it would mean that the marginalised poor black communities in South Africa are again being neglected and denied basic human rights to a safe and secure environment.
The wide adoption of 6-to-8-metre solar street lights have seen great success in secure areas where the risk of vandalism and theft is lower. These street lights are designed to provide sufficient illumination according to the SANS specifications while using smaller solar panels and batteries, making them a more sensible option.
“We are guaranteed continuous advances in technology that will soon allow for a SANS-compliant solar high mast to exist. Unfortunately, low-powered LED floodlights have no practical use being mounted on high masts,” says Marais.
Enquiries: www.genluxlighting.co.za
