Solar module efficiency
SolarSaver project in Hatfield, South Africa

In Africa, it is estimated that by 2035 solar photovoltaic (PV) projects will contribute 9.8% of overall electricity generation making way for solar module efficiency research and development.

In South Africa, the National Energy Regulator of South Africa (NERSA) announced recently that it has the go-ahead to license 500 megawatts (MW) per year of embedded generation projects each with an installed capacity of under 10MW. 

Those projects will now be able to proceed without having to seek prior approval from the energy minister. These sorts of projects typically cover residential, commercial and industrial sites, and would include properties such as retail centres, warehouses and offices. 

Did you know? Capetonians must register their small-scale embedded generation (SSEG) systems. Find out more here.

Along with shifts in the traditional energy market, consistent and rapid innovation in the field of solar PV places this energy generation alternative at the forefront of efforts to reduce our collective dependence on fossil fuels. So says Tim Frankish, managing director of SolarSaver, an independent local renewables company that provides capex-free solar solutions to businesses both here and in a growing sub-Saharan market. 

Frankish states: “The solar energy sector is highly innovative and the past few years have seen a rapid growth in the range of available solar panels, also known as modules. These modules now come in innumerable different sizes and capacities, and employ a range of different technologies. These developments are all aimed at driving efficiency, from both a technical and a financial perspective.” 

Influencing solar module efficiency

Manufacturers, such as Canadian Solar, have been successful in developing higher performance modules that include features such as passivated emitter real cell (PERC) and half-cut cells.

“These technologies now see Canadian Solar’s HiKu modules, for example, achieving efficiencies of up to 18.8% on 415 watt ratings,” notes Frankish. “That’s a big jump from the 16.4% efficiencies and 260 watt ratings we saw as recently as 3 years ago.”

The use of high solar module efficiency means that installers require fewer of them to yield the same system output. This benefits clients through a reduction in a project’s BOS (balance of system) costs and enables more power to be generated off a smaller footprint. The latter is particularly beneficial for high energy consumers that have limited roof space, for example.

Another innovation that is making a significant impact on the solar landscape is the bifacial solar module. Bifacial modules include solar cells on both the front and rear sides, enabling sunlight to be captured both from above and below. 

Frankish explains, “In contrast to the one-sided absorption of traditional panels, bifacials are also able to absorb light that is reflected off the ground or roof. Our experience shows that these modules, if installed correctly, can yield 10 to 30% more than similar systems using traditional modules.” 

Bifacial module installation in practice

SolarSaver incorporated bifacial modules in its solar installation at Gondwana Collection’s new lodge in Namibia, The Desert Grace. The modules were mounted on custom-built carport structures and Frankish believes they brought more to the project than just higher energy yields and solar module efficiency.

“Bifacial modules don’t have any plastic backsheets so they look great from below. Our engineers were therefore able to combine performance and aesthetics to give our clients a truly unique solution,” he explains.

Frankish says that bifacial modules do however pose a challenge for parties looking to finance solar projects. “The challenge with bifacial panels is the unpredictability of power output as the type of ground behind the modules, and the way the modules are mounted, has a big influence on the levels of output achieved.

“It can therefore be difficult to model what the installation will produce. The Desert Grace project was the first installation in Africa to utilise Canadian Solar’s bifacial modules and provided us with an important test case.”

SolarSaver has subsequently used bifacial modules at a number of other sites in Namibia and will soon start installation of similar carport structures at Cape Point Vineyards, a wine estate near Cape Town.

This story will also interest you: Tilt solar PV market to record 9% growth in five years’ time