Will Larger Solar Module Sizes Work For Everyone?

As Panel Sizes Grow, Time For A Reality Check For C&I Buyers & Residential homeowners looking for Rooftop Solar.

The second half of 2020 marked a new shift in the solar module segment, with many manufacturers announcing the launch of bigger, better & higher output modules. Some have called these the next level of technology and innovation, while others have been nonplussed at all the fuss. But with claimed power output on these modules crossing 500 W and now, even 600W in some cases, potential users can no longer ignore this new shift.

So first up, is a bigger module necessarily the next stage of technology progress or innovation? One would have to say here, that the simple answer is no. If there is one thing technology has become associated with in recent decades, it is with making everything more compact, isn’t it?  Technical experts argue better technology has been powered by better cell efficiency in recent years. This has enabled manufacturers to install more watts per square meter, besides a reduction in every single other raw materials for the same level of output bringing down overall system prices. Thus innovation in solar panel is powered by cell-level advancement.

Developers and installers we spoke with confirm that big is better as long as comes with higher  efficiency, or watt per square meter(w/m2), or energy density. That brings real value for large, utility scale projects in using them. But these bigger form factors designed for utility scale projects, may not be ideally suited for rooftop projects. Bigger is definitely not better in these applications – all developed & mature solar markets like US, Australia, Germany and Japan continue to focus on 60/66cell products in rooftop segment. The reasoning is simple- ease of installation and compact size and handling making it the first choice for a homeowner or commercial property looking for rooftop-system.

As the biggest and highest cost component of the solar plant, any change in module sizes will also impact everything that goes with it. Be it racking systems, installation techniques, and even the software to manage the plant and its new high output panels. More than that, the varying sizes of these solar panel means that the standardisation of 60 and 72 does not hold anymore and that the other component manufacturers like invertors and BOS have to optimise accordingly. Thus, there is the issue of whether the other component suppliers are up to speed with their own changes, or behind the curve.

On the other hand, for non-utility projects, it is these advantages that become disadvantages too. Large corporate and residential rooftop projects for instance come with limited sizes and shapes sometimes, where really large modules can fail the flexibility test, Add to it the challenges of installation on the rooftops which requires much more robust handling as they are really bulky increasing the real chances of micro-cracks considerable With the industry grappling between a move to the 182mm standard or the 210mm standard (for cell size) among the global majors lately many firms focused on the non-utility segments would rather focus on efficiency, as their clients may not have the luxury of acres of space or a single minded focus on LCOE.

Even the firms making the larger modules caution that they do come with special requirements. Thus, while watt for watt, one can pack in more for transportation now, the larger module size also means special care during packing and transportation, to avoid any breakage. Keep in mind that pallets in use till now were designed with a particular panel size for placing inside shipping containers.

Similarly, modules designed until now with the optimum width of human hands when installing, need to be sized for a maximum of two people to handle it comfortably. A one way move towards larger sizes is also impractical due to

For firms like REC Group, the Norwegian module brand manufacturing out of Singapore, the ‘bigger is better’ argument  is not relevant, it claims. With a focus on the non-utility C&I and residential segment, REC has invested in efficiency through its HJT (Heterojunction technology) half-cut cells product, REC Alpha Series, that has very high cell (and module) efficiencies. The higher power density, the firm believes, will take out the need for a larger module size to a large extent. Also, the HJT is a cell-level innovation which combines the best of the Mono PERC and thin films making it a next generation technology.

REC Group’s Alpha Series. Efficiency Over Size

Rohit Kumar, Director,  Indian Sub Continent, Middle east And Africa (REC Solar)

Talking about this trend Rohit Kumar, Director for the Indian Subcontinent, Middle East & Africa at REC mentioned that “At REC we deliberately choose not be part of the race to go beyond 72 cell size, as there is no end to it and ultimately the consumer suffers from a lack of standardisation. As a company that has  been making advance technology solar panels for 25 years we really want to give the Indian customers the best quality products that are loved globally in the same form factor that have stood the test of time, and which is largely 60 cell and now 72 cell.”

Eventually it’s the consumer who has to be smart here, and fall for the lure of size and higher wattpeaks without ensuring that it really is the best option for her.