Electricity + Control December 2018

HAZARDOUS AREAS + SAFETY

Lightning and surge protection for solar installations across Africa It is well-known that Africa as a continent has the highest in- cidents of lightning strikes annually. A significant variance in lightning flash densities across different parts of Africa requires unique solutions across countries. DEHN AFRICA is building its experience and reputation in creating tailored solutions for solar energy installations across the ‘lightning continent’. Julienne Puttkammer, part of the technical team at DEHN AFRICA, says, “Since 1995, the National Aeronautics and Space Administration of the United States (NASA) has been gathering data which shows where lightning occurs on the earth, with multiple orbital instruments called LIS and OTD, which are installed on satellites. The data is then processed and represented as yearly average lightning flashes per square kilometre on various maps. These maps show con- clusively that Africa is the continent with the most hotspots of lightning activity, and also how the lighting flash density tends to be highest around the equator. The maps show that the highest amounts of lightning flashes occurred in the far eastern Democratic Republic of Congo, as well as at Lake Ma- racaibo in Venezuela.” “However, in the same way that we remind the world that Africa is a continent consisting of 54 individual countries, and therefore should not be treated as one big homogenous area, so we also need to be aware that the lightning statistics change across the continent also, country by country and region by re- gion. DEHN AFRICA has worked on a number of solar instal- lations across the region with regards to lightning and surge protection, and we are acutely aware of the differences that must be accounted for at the design and installation stages.” Across Africa, says Puttkammer, DEHN AFRICA has seen a focus on ground-mounted utility-scale PV installations, and has worked on projects that are both government-sponsored as well as private sector initiatives, or even a mix of the two. The company has consulted on installations in countries including South Africa, Namibia, Mozambique, Mauritius, and Uganda. “Solar energy challenges across Africa can be vastly differ- ent. Satellite observations have shown that lightning occurs more often over land than over the oceans, and that lightning seems to happen more often closer to the equator. Although there are countless factors, we also know that many of the world’s lightning hot spots are associated with steep terrain, because a sharp slope helps to set up the clash between warm and cool air masses that can drive thunderstorm development. “These facts are consistent with our experience in Mauri- tius, for example, which is an island quite far south of the equa- tor and where the lighting ground flash density was low, and our experience in Uganda, which is closer to the equator, more mountainous and where the lightning ground flash density was much higher.With each new solar project in Africa that we work on, we at DEHN AFRICA are proving ourselves to be the go- to company for lightning and surge protection for solar farms across the continent, as this vibrant source of renewable en- ergy continues to gather momentum,” concludes Puttkammer. Enquiries: Hano Oelofse.Tel. +27 (0) 11 704 1487

Electricity + Control

DECEMBER 2018

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