With increasing concern around the cost and sustainability of energy, Harvard Engineering explain how efficient street lighting can play its part

Lighting is responsible for 19% of global electricity use and around six percent of global greenhouse gas emissions. As a result, the cost and sustainability of lighting is of increasing concern for the public sector.

However, street lighting plays an important role in any urban area, contributing towards safer roads and greater security in residential, business or municipal areas. In a bid to cut costs and meet sustainability targets, some councils have turned to switching lights off completely. This move, however, has been met with disapproval due to the impact on public and road safety. However, keeping street lights lit at 100% increases costs and damages the environment, which also has a negative result.

What’s the solution?

This is where efficient LED lighting can play a vital role as it has the potential to deliver major cost and carbon reductions for councils and today represents a more cost effective alternative to traditional street lights. A switch to LEDs (supported by a street lighting control system) is proving that councils can save money and energy without compromising public safety and security.

The cost effectiveness of an LED is due to less power usage and a longer lifetime. However, the most significant savings are realised because LEDs can be networked, monitored and controlled remotely.

Street lighting control systems allow real time remote control of outdoor lighting and are well suited to the rapid responsiveness and electrical characteristics of LED technology. When applied to LED lighting applications, smart controls can increase public safety, enable monitoring of luminaire performance, and maximise both the energy efficiency and longevity of LED products.

Harvard Engineering has developed a system which allows street lighting to be wirelessly and remotely managed using a smartphone, laptop or computer. According to Russell Fletcher, sales and marketing director at Harvard Engineering, the company’s LeafNut system offers the ability to accurately control and monitor all assigned lighting units by providing remote wireless, web-based switching and dimming. “It also gives users the ability to remotely monitor and control on and off times, change the power output, monitor lamp life and failure, and provide early warning reports that will reduce maintenance costs,” he explained.

Key installations

The system is being employed throughout the globe to help cut street lighting energy costs and associated carbon emissions. For example, in the UK one of many municipal authorities starting to realise the benefits of installing the LeafNut wireless monitoring system is Westminster City Council in London.

In an effort to meet new directives set by parliament that require the council to reduce carbon emissions by 60% – a figure which could rise to 80% as interim targets have been missed – the council wanted to introduce a solution to eliminate wasted energy from its 15,000 street lights.

“The council’s aim was to find a solution that would significantly reduce energy usage and save money, whilst being easy to maintain but without compromising public and road safety,” said Fletcher. As a result of the LeafNut installation Westminster City Council achieved initial savings of 30% on its energy bills, as well as a significant reduction in the carbon emissions produced from its street lighting infrastructure.

The scheme targeted Westminster’s main road networks and was focused on identifying areas where street lights that burned brightly in the early hours of the morning, or after rush hour, served little purpose. “Due to the flexibility of the LeafNut system, operators are now able to reduce the lighting levels across a variety of locations in the area, whilst continuing to provide brighter lighting at ‘hotspots’ such as main road junctions, or at specific times,” said Fletcher.

In residential areas the system provides operators with an easy way of dimming street lights by 25% during the early hours of the morning, when it isn’t necessary to have every street light fully lit. “Although there were initial concerns about a rise in crime, these proved unfounded as the reduction in brightness is barely noticeable to the naked eye,” Fletcher explained.

Despite the benefits of installing a street lighting control system, one perceived barrier to implementing such a system is cost.

As a result and to support those interested in cutting costs and saving the environment, Harvard has launched a finance scheme called ‘Install to Save’ (in acknowledgement of the government’s ‘Invest to Save’ scheme). Through the finance scheme councils installing LeafNut will have their capital expenditure covered by Harvard, and will then pay Harvard back with the savings achieved from the installation over a period of ten to 20 years.

Harvard Engineering


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