The AltGen team visiting Lourensford and viewing a SPS solar rooftop setup

Industry Myth-Busting by Sustainable Power Solutions

At AltGen we believe that there is no knowledge more valuable than what is gained hands-on. Technical know-how from site visits with leading industry players enables us to screen candidates far more effectively for our clients, thus really unpacking the nitty-gritty of who is a great candidate from a technical standpoint. Sustainable Power Solutions (SPS), having completed over 200 solar installations since 2008, has plenty of advice to offer from experience. Our team recently had the privilege of touring Lourensford Wine Estate with a key member of SPS, to view the solar tech they have installed and to see what we could learn from one of the leaders in the industry. 

Why Lourensford?

Lourensford Wine Estate has been around since the 1700s and finds itself in the heart of the Helderberg mountain reserve. Surrounded by rich biodiversity, it is considered one of the most beautiful estates in South Africa. A key strategy in their business model is environmental sustainability, ensuring the care and vitality of plant and animal life on the estate, including the Cape Leopard. It made perfect sense to reduce their carbon footprint by utilizing small-scale renewable energy systems to power wine-producing activities.

Two Grid-Tied rooftop solar installations have been placed on Lourensford’s wine cellar and packhouse where they generate enough energy to power a large portion of the winemaking and storage operations. Solar electricity solutions are becoming increasingly attractive to businesses in Sub-Saharan Africa, a pretty sunny place, where SPS operates. Besides the fact that the solar resource needed for solar power generation is very abundant in these regions, another pull toward this technology is the renewable energy requirements imposed by European countries on companies looking to trade within the EU. This means that companies wanting to break into that market without sky-high costs and tariffs being imposed would need to be at least partly powered by renewable sources. The Lourensford Estate took this a step further when they partnered with SPS, supplying a significant portion of the wine cellars’ power through its rooftop solar panels

The Lourensford Estate was an ideal location for SPS. A rooftop solar installation is well-suited to the energy requirements at Lourensford for the same reasons that shopping centres were the first sector to install solar PV rooftop panels.  The availability of large, sprawling roof space, the profile of energy consumption of seven days a week, 365 days a year, air conditioning, refrigeration, and lighting driving consumption and the fact that the majority of energy is used during daytime hours. This means that not only can solar be installed productively, but the power produced will be consumed effectively, saving the farm wasted space, energy, and costs. SPS has successfully installed a 500kWp Solar PV system on the roof of the wine cellar, helping reduce electricity costs as well as their carbon footprint.

The Myth of Angles and Directions Busted

Our team ventured up onto the roof of the wine cellar to get a closer look at the approach SPS is employing at Lourensford. The Estate has a few different solar systems installed, but the one you see on the roof of the cellar is unique, innovative and groundbreaking.  The Lourensford wine cellar is located in a lush, mountainous area in the Cape Winelands and has what most in the industry would consider a large number of disadvantages.   The facility has low-sloped roofs, mountains and trees surrounding the installation area creating many shading challenges. This didn’t deter the SPS team from implementing a very effective solution. 

A common misconception is that solar panels must be placed facing perfectly North at a 20-degree angle to maximise efficiency and anything else is unacceptable. This set-up is achievable when it comes to ground-mounted solar solutions, but could limit opportunities in the rooftop solar market. SPS installed the panels on Lourensford’s roof at angles ranging from 3 degrees to 7 degrees and orientated from North and even South-East. The lower generation from panels that are not optimally placed is not as pronounced as previously thought and on a low-angle roof, it could be as low as 5%.  This showcases the space for creativity and innovation in the rooftop solar industry, and suddenly makes a variety of structures more feasible for this technology.

Efficient or effective

Another good reason for being dynamic with panel angles and orientations when it comes to rooftop solar is the optimisation of the energy output on complicated structures. By placing panels parallel to the existing roof sheeting rather than using angled structures (to improve the angle to the mythical 20 degrees) allows for more panels to fit into the same roof area. This leads to a greater energy output from the available area and highlights the benefit of quality engineering and design.  It all comes down to buyer preference: as many watts as possible from an optimally angled panel, or the maximum output from the area as a whole.

We were surprised to hear that a single panel in the shade in a grid-tied system does more than just produce less energy.  Where one portion of a panel is shaded, all the other panels connected in that string will not be able to produce energy efficiently. This could affect more than 20 panels and reduce the available energy substantially.  Due to quality engineering and design, the Lourensford system has proven to be so lucrative that any spaces on the roof that were left empty will soon be filled with more panels.

Lourensford’s PV panels channel the energy from the sun to a large number of inverters, with each section of panels angled at the same orientation and angle being directed to the most appropriate inverter. Through this layout, the panels on different portions of the roof can deliver energy at different levels of efficiency at different times of the day.  Another learning on the day is that modules are slightly elevated off the roof, creating a draft underneath. This is done to avoid overheating as a solar PV panel produces electricity from light, not heat. They would produce the best results on a cold summer’s day! This goes to show the importance of constantly learning, experimenting, and even taking risks when it comes to understanding and testing solar technology.  

SPS offers fully funded Power Purchase Agreements (PPA) and owns, monitors, and maintains the systems themselves. This motivates them to invest in good quality, long-lasting equipment, and to ensure that the whole system remains in good condition through a rigorous maintenance program.  Our team is beyond appreciative that we were able to learn more about the various technologies we get to work with through a quality market player like SPS. Through this site visit, our consultants have gained an insight into how important the movers and shakers designing these systems are to optimising costs and operations, and how valuable candidates with ideas and knowledge like this can be to companies growing and disrupting the renewable energy industry.

Where to Next?

Lourensford is one of SPS’s successful forays into supplying an agricultural consumer with a bespoke and viable renewable energy solution. Their myriad of previous projects includes work in the commercial, industrial and tourism industries, with grid-tied, off-grid, battery supported solutions and IPP. Sustainable Power Solutions is a pan-African solutions provider with installations across Southern Africa including completed projects in Kenya, Seychelles, Namibia and many other countries making it a force to be reckoned with. Besides gaining entry to European markets companies with innovative renewable technology integrated into their operations, this case study showcases how feasible and lucrative the renewable energy industry and clean tech can be. AltGen has been thrilled by what we have learnt from them about industry myths and our local market! 

The AltGen team visiting Lourensford and viewing a SPS solar rooftop setup