Public Lighting

Securing and sustaining smart energy savings

Public lighting is a crucial visual aid. It reduces road accidents, increases safety and security, and may ultimately attract investment and growth within a municipality. However, it may also significantly contribute to a municipality’s electrical consumption and must be appropriately managed. By Danielle Petterson

First introduced in 1878, public lighting has become an important part of most municipal master plans or town planning development strategies. Bjorn Smidt-Hart, senior engineer: Power and Energy, SMEC South Africa, describes it as a

Bjorn Smidt-Hart, senior engineer: Power and Energy, SMEC South Africa service with the power to indirectly promote stimulus into the economic growth, and a state of well-being, within a municipality.

While public lighting may assist in generating revenue indirectly for a municipality, it also adds to the electrical consumption and operational costs. Smidt-Hart stresses the importance of implementing energy-efficiency initiatives, which assist in reducing energy consumption by municipalities, thereby saving money and alleviating strain on the electrical grid.

Energy efficiency

Energy-efficiency initiatives focus on replacing existing non-efficient luminaires with modern energy-efficient LED luminaires, as well as specifying LEDs for new installations. According

The Mt Edgecombe Interchange in Durban

to Smidt-Hart, LEDs have a longer operational life, providing consistent and affordable public lighting infrastructure with reduced maintenance and operational costs. In fact, it is estimated that South African municipalities could save 40% of their total public lighting expenditure per annum by switching to quality LED luminaires.

SMEC South Africa was appointed by the South African German Energy Programme (SAGEN), implemented by the German International Development Cooperation Agency (GIZ) with funding from the Swiss government through SECO, to develop and implement

A well-lit pedestrian bridge on the N1 in Botlokwa improves visual safety at night

a minimum energy performance standard document for street and area lighting to be used in pilot projects.

Lucky Maduna from GIZ SAGEN emphasises the importance of building capacity in municipalities to select energy-efficient lighting options. “We at GIZ feel the minimum energy performance standard technical document will enable municipalities to procure the highestquality lighting with the best potential energy savings,” he says.

The initiative has resulted in the roll-out of pilot Energy Efficient Street Lighting Retrofit Projects (EEStLRP) at five municipalities located in the Eastern Cape, Free State, Gauteng and KwaZulu-Natal. The pilot projects will see around 2 900 fittings replaced with energy-efficient LEDs. The old luminaires and lamps, some of which contain mercury, are to be environmentally conservatively and safely crushed and disposed of.

Using conventional non-efficient luminaires, the five municipalities were consuming nearly 8 million kWh per annum for public lighting, at a cost of approximately R11 million per annum. Following the implementation of the energyefficiency initiatives, the energy consumption could be reduced significantly to 4.8 kWh per annum. This may result in an annual saving of R5.9 million across all five municipalities, excluding operational maintenance, repair and security expenditure – a saving of around R1 900 per fitting per annum.

Another example of savings is demonstrated by the Mt Edgecombe Interchange, where SMEC South Africa was appointed by the South African National Roads Agency Limited (SANRAL) to develop a street lighting solution in addition to the overall upgrade of the interchange itself. Because it is a free-flow interchange, good-quality lighting is essential for motorists travelling at speed. SMEC South Africa opted to light the graded interchange with lighting along the bridges themselves, which provides safer, uniform lighting for motorists on all levels of the interchange, which is not necessarily provided by high-mast lighting. A total of 510 LED luminaires were installed, equating to a saving of around 282 tonnes of CO 2 per annum compared to traditional non-efficient luminaire lighting installation.

The LEDs are estimated to consume 401 500 kWh per annum and generate approximately 433 tonnes of CO per 2 annum versus 662 475 kWh per annum and 716 tonnes of CO per annum for 2 a conventional, inefficient lighting system for the interchange. The annual energy saving is 260 975 kWh – enough to power approximately 30 households per annum.

Combating vandalism

Unfortunately, the lighting system at the Mt Edgecombe Interchange is facing severe vandalism problems. Poles have been cut down and removed, and luminaires and cables stolen. SANRAL has plans to install more secure systems, poles and masts to try to prevent vandalism.

This is not a unique challenge being experienced by SANRAL alone. Vandalism is a long-standing problem in South Africa. Measures such as tagging or barcoding cables to identify stolen cables, constructing more secure vault-type power supply kiosks, and even implementing more vandal-resistant lighting poles and luminaires may not deter all criminal acts. More extensive measures like surveillance and active security are helpful but can only be implemented where cost appropriate.

Smidt-Hart believes that infrastructure should be protected by legislation so that public infrastructure may become a high-risk item. “Theft and vandalism are a step backwards in delivering services to a community,” he says.

Quality lighting

Although implementing energy-efficiency initiatives should be a priority, SmidtHart cautions that they should not be undertaken at the expense of lighting quality. The focus should always be on energy saving while maintaining quality and compliance to luminaire and lighting level standards, namely: • SANS 10098: Public Lighting (road and street lighting) • SANS 10389: Exterior Lighting • SANS 10114: Interior Lighting • Occupational Health and Safety Act (No. 85 of 1993) Environmental Regulations for

Workplaces, 1987. Should these standards not be met, the safety of the general public may be at risk. Landowners or employers could be held responsible for any injury within the workplace that may occur as a result of poor lighting, warns Smidt-Hart.

Poor lighting contributes to night-time road accidents, especially those involving pedestrians. While this is typically considered in urban and residential areas, other high-risk areas, such as around informal settlements, may not necessarily be taken into account. SMEC South Africa has been involved in lighting several bridges to improve pedestrian safety, such as the Isando and Regents Park pedestrian bridges.

Improving the quality of public lighting can also promote better use of open spaces, increase non-motorised transport activities, promote urbanisation, and improve safety and security. Smidt-Hart cites the Ekurhuleni BRT route from Thembisa along Zuurfontien Road to CR Swart Drive, which includes nonmotorised transport lanes and pedestrian walkways, as an example.

SMEC South Africa designed the installed LED lighting system with incorporated telemanagement devices to assist in the control, monitoring and maintenance of the lighting system. Illumination along the new public transport route resulted in an increase in pedestrian volumes and the number of people using the route to exercise in an area where people were previously cautious to do so.

Automation and sustainability

For South Africa, Smidt-Hart emphasises the need for sustainable solutions. “Before you advance, ensure that you have a sustainable and operational system. It’s about mitigating risks and moving forward from there,” he says.

Lighting on the Regents Park pedestrian bridge in Johannesburg

Municipalities need to identify, understand and mitigate the risks that may undermine and challenge the existing and future delivery of the public lighting service. Some identifiable risks include theft and vandalism, behaviour of communities, and the ability of municipalities to operate and maintain public lighting infrastructure.

The efficiency and quality of a municipality’s sustainable public lighting service could also be an advancement into the Fourth Industrial Revolution, and significant potential exists to merge IoT (internet of things) systems with public lighting infrastructure. IoT can help to better control lighting systems, by identifying operational or faulty lighting systems, automating lighting installation operations and possibly only illuminating areas that need illumination. Wireless communication systems could be incorporated into the public lighting systems. These systems may also be set up with metering units to improve asset management, metering and billing of various utility services.

Additional opportunities exist for using street light poles to piggyback other systems, such as Wi-Fi hotspots, surveillance systems, or as a telecommunications platform, which may help generate income for a municipality. “It’s a different model to consider when it comes to smart city implementation,” says Smidt-Hart.

The importance and potential of the public lighting infrastructure should not be underestimated. Instead, public lighting infrastructure should be considered a financial investment. “The return on investment could be secured through the implementation of responsible initiatives and strategies that promote sustainable and efficient quality public lighting infrastructure,” says Smidt-Hart.

“Sustainable and efficient quality public lighting could ignite the possibilities of developing and advancing municipalities, communities, industry, businesses, families and individuals to an improved state of wellbeing or smart city status worthy of the Fourth Industrial Revolution era,” he concludes.

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