Cape Town's low-carbon street lights
Tuesday, 17 November 2009 14:54
New energy-saving street light measures in Cape Town are a good example of a low-carbon choice also being the most obvious choice.
In Cape Town, it started because the City needed to save costs and conserve electricity while ensuring that further load-shedding (rolling black-outs) did not compromise the safety of residents.
As a result, a savings plan was developed to save at least 10% of the current street lighting electricity demand in the areas where lamps are replaced, explains Brinley van der Schyff, public lighting operations manager, City of Cape Town.
The plan included short term and medium term measures to ensure savings are sustainable. One of the medium-term interventions was to accelerate the replacement of 80-watt mercury vapour streetlight bulbs with 70-watt high-pressure sodium bulbs.
It's simple, says Shaun Arrowsmith, acting manager for public lighting at the municipality. In replacing the bulbs, those 10 watts add up: there are more than 117 000 of these 80 & 125W mercury vapour streetlights in the city, and the first 29 000 in the City supply area and an additional 18000 in the Eskom Supply area have now been replaced.
The new, brighter, yellow/orange lights will eventually be visible across the city giving off 5 900 lumens each (compared to the 3 700 lumens of each white-light mercury vapour bulb). High-pressure sodium lamps also have a significantly longer lifespan, and don't require special mercury-disposal facilities.
