JinkoSolar’s R&D team is always pushing the boundaries as developers of solar applications large and small demand higher output and leaner costs. EcoGeneration spoke to JinkoSolar Australia and New Zealand technical service manager Dan Su about trends in delivery among large commercial and utility scale projects.
How did high-output panels evolve? Was it customer demand or competition among manufacturers?
Before, solar farms were fighting on LCOE calculations with coal, nuclear and other energy generations, but in the last five years that barrier has been crossed and now the real competition on LCOE is between wind and solar. As we know, globally it has become harder to achieve both viable PPAs and finance, together with the reduction of government subsidies such as LGC.
Solar projects are pushing for lower LCOE, and this is not just the result of a mere calculation of dollar per watt on the module itself. In fact, EPC and project owners are also looking for a balanced system where the combination of higher efficiency and higher power output, together with trackers and bifacial technology, can give a great contribution to reduce LCOE, and same goes for residential and commercial markets as the competition is quite strong in those sectors.
In the past years we forecast that the module power class would evolve by 5-10W each year. Now to everyone’s surprise we are achieving an exponential escalation in terms of module power output: from 250W to 470W modules over the past five years we are now witnessing a 50-100W jump just from 2019 to 2020.
Although mono PERC is now mature on the technology side, there are several new technologies driving change. On the module level there is half-cut, multi-busbars, tiling ribbon and bifacial technologies. Emerging technologies such as gallium doping and N-type are also helping boost the modules performance even further.
Can you talk about the changes in wafer sizes in the industry and how buyers are responding?
Since their launch, there is a very strong demand for 500W-plus modules, especially in the utility sector. Project developers are looking at better ROIs and EPCs aim to achieve a faster installation and space optimization, with less modules and trackers to be installed. So bigger wafer products make sense as they bring a reduction of 10% in BOS, require less trackers and have a smaller footprint. On top of that we have a bifacial variation which gives an additional 10% generation.
We have seen many different wafer sizes from 2019 to 2020 and although each module product has its own advantage there are also challenges to overcome, such as higher current or voltage, mechanical loading on mounting solutions and logistics, pushing the industry to evolve.
Personally, I am glad to see the market – and especially the major manufactures – has come to an agreement on certain cell sizes, either 182mm or 210mm, which will help to bring back the focus on improvements at module level and cell efficiency.
Are buyers holding off on orders to see how high-output panels perform?
The demand is very strong for all types. Utility-scale and commercial are welcoming the shift to 500W-plus as we can see in many tenders and EOIs for 2021 projects.
But if projects make commercial sense and have ticked all the boxes, developers won’t wait for the next generation of modules. This market moves so fast that when a project reaches COD, the next generation of PV modules will be already on the market, so you cannot be always on top of the tech curve.
Because of the covid-19 pandemic, projects have slowed slightly, so during transition phase there are projects that are still going for closure with our 470W Tiger module, launched in late 2019.
With regard to the residential market, considering also the trends towards 6.6kW system, 330W is still the most popular panel, but we can see the increasing demand on higher output modules, such as the 370W and 390W N-type that JinkoSolar launched earlier this year. We are also expecting big wafer products to be deployed in this market shortly.
Can high-output panels be deployed simply at utility-scale or do they suit completely different types of system design?
Recently the gap between utility scale solar farms and C&I space is diminishing. If before commercial and industrial projects were closer to residential market, they have now started adapting to utility-scale solar farms and implementing the same model.
Physical size of the module sometimes becomes a limitation for rooftop installation and therefore we are upgrading our product line from 330W to 370W or 390W, as well as adapting to the size-wise big wafer products, which are still less than 2m in length.
We believe these high-output modules in a compact format shall be more visible across the market segments and system designs. In the end it is all about economics and ROI, and that derives from the higher output modules usage.
What are some details of the cell technology that allowed improvements in output?
The technology used for big modules is not new, and for years manufacturers have been trying to find the balance in between efficiency, power class and performance, at both module and cell level.
We can’t just keep sizing up with the same p-type wafer, to improve cell efficiency we have introduced N-type technology which can reach over 24% cell efficiency. N-type also helps improve the degradation and therefore it assures a long-term return on investment.
Speaking of output improvements, one of the main issues to address is the “power density”, and JinkoSolar has introduced the tiling ribbon technology, that allows to reach the balance between higher power and size. Besides, JinkoSolar is the first manufacturer to introduce 78 and 66-cell products instead of the traditional 72 and 60 cells, and this is a simple but very efficient upgrade. As an industry leader, JinkoSolar took this initiative launching bigger-size modules with Tiger 470W in September 2019, now the whole industry has come up with a similar module size and the system companies are ready to adapt their products to these modules.