In recent years, the efficiency of solar PV technology have grown rapidly due to various factors including technological advancement and cost reductions in materials among others.
However, according to Milicent Chidamba, sales manager for South Africa at JinkoSolar, even with extensive R&D advancements all solar PV projects – whether utility scale or a C&I project – have something in common.
This common denominator is made up of three conflicting demands that have to be met, namely maximum performance, lowest cost and durable products.
Adding to this, JP de Villiers, Managing Director, Soventix South Africa stressed that the status quo of renewable energy systems is to produce the most amount of energy with as little space as possible.
When examining current module technology, by far the most mature and popular are half-cut PERC cells, says De Villiers. He adds: “We are seeing those becoming more and more of the norm for high-efficiency modules. To get modules to improve even further, we’re going to have to look at the development of much larger wafers.”
This process is currently underway; however, De Villiers added that the industry is reaching the point where technologies and breakthrough in cell technology is becoming more challenging to achieve. “Manufacturers are having to think outside the box. Whilst high-efficiency panels are higher in price, they result in more power per square meter, requiring less modules and space with lower BOS costs and less installation,” he stated.
During a technical presentation, hosted by ESI Africa at the Digital Energy Festival, Chidamba took the audience on a brief journey of how the company’s product portfolio has evolved over the past three years, in response to the progression of the PV industry.
Chidamba explained that the Tiger Pro Series is based on a 182 millimeter wafer, which is fast becoming an industry standard. She pointed out that both panels come with a product power warranty of 12 years, while the mono facial offers a “linear power warranty of 25 years, and for bifacial we’re offering a linear power warranty of 30 years.”
She acknowledged that the 78 cell module can reach a maximum power output of 580 watts but that “it is only offered as a bifacial with a transparent back sheet”.
“The key technology that we have employed in this particular module is the tiling ribbon technology, which eliminates the cell gap and in that we are able to reach the highest power output for that module in that class as well as the high efficiency,” she noted.
Advanced technologies for reduced LCOE
According to Chidamba, the company’s product development strives to incorporate all of these three conflicting demands. “In terms of understanding these demands, particularly LCOE, the Pro series saves on your system costs. This is achieved in two dimensions. The first one being the power class maximisation; Tiger Pro Series modules are able to reach 540 watts on a 72 cell and 580 watts on the 78 cell,” Chidamba stated.
Along with technology advancements, Chidamba highlighted that recent trends have reduced the number of modules required, “so with the reduction in the number of solar panels that one requires in the project, we are able to reduce the civil work costs, as well as the BOS cost.”
In general, installation costs and maintenance costs are closely tied to the number of modules that one can deploys, she explained.
Drivers of high cell efficiencies
Though the n-type cell was the first cells to be discovered, p-type cells have dominated the solar industry, de Villiers underlined in his technical presentation.
“The reason for that, is the space race. P-type solar cell modules proved to be more resistant to space radiation and degradation. With that kind of funding and that kind of process being involved, a lot of effort and resources were put into the development of the p-type cells.”
He says manufacturers are turning to n-type cells because of certain advantages such as being immune to boron-oxygen defects, which leads to decreased efficiency and purity in p-type cells. “N-type cells are not affected by light-induced degradation (LID).
“R&D continues on both types of solar cells; looking for ways to improve the efficiency of p-type solar cells and bring down the cost of manufacturing n-type solar cells,” de Villiers added.
In efforts to decrease manufacturing costs, gain efficiency and increase power output, manufacturers have started moving away from the standard 156mm cell size in favour of larger sizes, stated de Villiers.
He also highlighted that there are a variety of cell sizes under development with the most popular being 166mm, 182mm and 210mm. “Larger cells have a greater surface area and when combined with the latest cell technologies, such as multi-busbar (MBB), PERC and ribbon, can increase module efficiency up to 22%,” de Villiers added.
Digital Energy Festival
The following sessions are still available to watch on demand as part of the Digital Energy Festival for Africa:
The Digital Energy Festival for Africa in 2020 was hosted jointly by four of Clarion Events’ leading energy brands Africa Energy Forum, African Utility Week & POWERGEN Africa (now Enlit Africa) and the Oil & Gas Council’s Africa Assembly and the leading energy journal ESI Africa providing six weeks of compelling content.