Part 2: Technical Series on Energy Efficiency

George Municipality has launched a  “ World of Tomorrow Festival 2019” to help increase public awareness of the importance of energy efficiency and the participating schools will present a 15 minute drama production.  

This initiative will take the message through children  – to the homes of George residents  – via an Industrial Theatre Competition which will introduce and explore the topic of “How do you mitigate climate change with energy efficiency.”

The dramas will highlight the changes individual residences and schools can make to become more energy efficient, which in most cases, will assist with curbing the effect of Climate Change – a  global topic. This project has come about as a result of the George Electrotechnical department participating in the second year of a National Energy Efficiency Demand program, which includes funding provided by the Department of Energy (DOE) for public awareness around climate change and energy efficiency.  The electrical engineering interns will be assisting with the  project and will each contribute a technical article on the topic.

Tickets will be available from 14th June  for the Primary School Production (31 July 2019) and the High School Drama Production (1 August 2019). Limited tickets will be on sale for attendance at the Gala Evening Production on 2 August 2019. The project is currently looking for sponsorship of prizes  in the form of a financial prize or energy efficiency product,  and any individual or businesses that would like to contribute is requested to make contact with Heather Stead on or 072 369 3304.

Our second writer, Thabo Yiga completed his BSc in Electrical Engineering at University of Cape Town and is an intern at George Electrotechnical Services, Planning department. 

Energy Efficiency in Lighting

The International Energy Agency stated in 2013, that electricity consumed from lighting accounted for 20% of the output of the world’s power stations. Bringing this closer to home, the energy crisis experienced by the national provider (Eskom) has resulted in the interruption of electricity supply in the recent months, known as load shedding.

It is thus clear that there is a need for the country to implement energy saving measures, and one of the simplest and most cost-effective ways of reducing energy consumption is by the use of energy efficient lighting.

This can be accomplished in several ways, such as:

1. Replacing incandescent bulbs with compact fluorescent lights bulbs (CFLs) at homes, schools and businesses.
2. Using new efficient fluorescent tubes to replace old fluorescent tubes in commercial buildings and local governments.
3. However, the most effective lighting technology is Light Emitting Diodes (LEDs). They consume about a third of the power compared to incandescent light bulbs and just over 80% of power compared to fluorescent light bulbs. LEDs can be used in many applications, for instance: residential and commercial buildings, street lighting, traffic lights and downlighters. LEDs are steadily becoming more affordable even to the working class.

To determine the amount of energy saved by a technology, such as LED lighting, consider the following:

Watt is the unit of measurement for electricity demand and Lumen is used to measure the brightness of light. This means that light bulbs with the same brightness could consume different wattage amounts, and this is what makes LEDs more energy efficient than incandescent and fluorescent light bulbs. Furthermore, compared to their counterparts, LEDs last longer and have an average lifespan of about 50 000 hours, with CFLs at 20 000 hours and Incandescent at 2 000 hours.

Let’s consider George Municipality as an example:

The Municipality is undertaking a project of replacing the current street lights with LEDs. One hundred and eighty (180) 432W High Mast lights have been replaced with 216W LEDs. To work out how much energy we will be saving, we take the difference of the two wattages and multiply that by the total number of lights being replaced. The lights are kept on for an average period of 12 hours a day for 365 days a year. This saves us (432 – 216) *180*12*365 = 170 294 kWh. One kWh is equivalent to one Unit, and if the standard residential tariff of R2/kWh is used, 170 294 kWh of energy costs R340 588. This is the amount saved per annum just by replacing 180 432W High mast lights with 216W LEDs. The actual Eskom Mega Flex tariff is used when calculating the exact cost saving. Even though the municipality spends money replacing these lights, they have their return on investment in a few years as they now pay less for powering their streetlights.

In conclusion, adopting and implementing these energy saving measures in lighting not only saves us money over a reasonable period, but it also ensures that we reduce the demand we require from Eskom and therefore will reduce the risk of an energy crisis such as load shedding. In addition, reducing our load demand means that Eskom burns less coal to generate electricity, which reduces air pollution, and ultimately mitigates climate change.

Caption: The five electrical engineering interns pictured are currently actively participating in the Department of Energy’s Energy Efficiency Demand Side Management (EEDSM) programme. Two of the interns are appointed under the EEDSM programme, two under the ISDG programme and one from IMESA. They are from the left: Lukas van Eck, Fezeka Mkhaza, Mphielo Ramotsamai, Phillip Van Niekerk and Thabo Yiga.

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