Sparks Electrical News December 2017

CONTRACTORS’ CORNER

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BANKING ON SUNSHINE: SOLAR SWITCH FLIPPED AT WESBANK AND FNB FAIRLAND CAMPUS

T he switch has been flipped on a world-class solar panel installation at the WesBank and FNB campus in Fairland, north of Johan- nesburg. Just 12 months after construction began on the large-scale renewable energy project, the 150 000 m 2 Fairland campus now supplements its electrical requirements using sunshine – help- ing the bank reduce its carbon footprint by more than 2 700 tonnes per year, while lowering its de- pendency on the local power grid and passing the benefit to the community of Fairland. With more than 5 000 WesBank and FNB em-

and FNB’s initiatives to earn a 5-Star rating for its Fairland campus from the Green Building Council of South Africa (GBCSA).

is capable of generating 1.99 MW – or enough to provide power to nearly 1 300 households. “Flipping the switch on a newera for our landmark building is very exciting. We have passionate people working to reduce our carbon footprint wherever possible, using innovative solutions along the way,” says Chris de Kock, CEO, WesBank. “Coincidentally, our move to renewable, sustainable energy comes at a time when the motor industry is facing similar challenges. I’m thrilled that WesBank can also say it is embracing the future of energy.” This solar panel installation is one of WesBank

ployees based at the Fairland Campus, shaded parking is at a premium. In 2015, a feasibility study was commissioned to establish the possibility of re- placing ageing carports with solar panels. What started out as a parking lot with 978 di- lapidated shade-cloth parking bays has been trans- formed into a futuristic field, with 7 647 reflective photovoltaic cells – across 1 010 parking bays – harvesting solar energy that helps power the cam- pus. Power from the solar panels is routed through 83 km of dc cabling, where power is stored across 83 dc-to-ac inverters. At peak efficiency, the system

Enquiries: www.wesbank.co.za

ILLEGAL GEYSERS AT RISK OF EXPLODING BECAUSE OF WATER OUTAGES N o solar geysers that comply with SANS could burst or explode as a result of pro- longed water outages. This is according to Arno van Wyk, managing director of solar hot water heating systems supplier, MrSola, disputing recent assertions that Phase One of the City of Cape Town’s critical water shortage plan could lead to solar water geysers bursting or exploding in af- fected suburbs. “Solar geysers and panels that are up to standard simply won’t suffer any major dam- age during awater outage. Electrical geysers are also only at risk of burning out their elements if they are completely empty. In neither of these cases could one reasonably expect an explosion.” One of the most important points to note, according to Van Wyk, is that all geysers, both electrical and solar powered, need to be fitted with temperature pressure release valves. “These valves open to release water if the temperature inside the geyser exceeds 90°C, or the pressure goes 50% over the certified working pressure of the geyser. Geysers are pressure tested at 200% of certified working pressure. The valve only closes again after the water temperature falls below 70°C. So if no cold water flows into the geyser; the valve remains open and the geyser still cannot burst.” He adds that the solar panel itself also has a steam release valve which ensures that pressure does not build up if no water circulates. “To prevent scalding if the water in the system gets too hot, a mixing valve is installed. This ensures a maximum hot water temperature of 55°C flowing to the point of use, i.e. shower heads and taps.” “Some cheaper solar heating systems that operate with vacuum tubes could potentially suffer damage if they do not have water but luckily there aren’t toomany of those in themarket. Most modern solar heating systems make use of evacuated tube technology, which does not have the same risks,” he adds. According to Van Wyk, all homeowners need to ensure their geysers are compliant with SANS codes. “If they are unsure, they need to have a professional inspect their system. In the City of Cape Town, it is a legal requirement that a home’s geyser is compliant and it is a prerequisite if one wants to sell a house.” Finally, Van Wyk states that there are some precautions homeowners need to take into account if their water supply is cut off. “Whether a solar or an electrical geyser, it is better for long- term maintenance and care if they are not empty. Therefore, we would advise that if there is a water outage in your area, use only cold water as far as possible. If you do need to use the hot water, switch off the geyser. This goes for a solar geyser, which has an electrical component, as well.

Enquiries: +27 (0)86 111 5115

SPARKS ELECTRICAL NEWS

DECEMBER 2017