Q&A: Why bigger is better

If you’re interested in the topics discussed in this Q&A, please join our pv magazine Webinar “Why bigger is better when bifacial modules meet single-axis tracking in the APAC region”, in partnership with Trina Solar Australia. The webinar takes place on Thursday, 1 April 2021 from 4 pm – 5 pm AEDT, Sydney | 1 pm – 2 pm AWDT, Perth / CST, Beijing, Singapore| 10.30 am – 11.30 am IST, Delhi. Register here. 

pv magazine Australia: Larger format modules such as the 210mm are the talk of the town at the moment, and Trina Solar is right at the centre of attention with its spate of new larger models. Are the larger formats a passing craze or will they become industry standard?  

Andrew Gilhooly, Assistant Director TrinaPro Business APAC: Well, at least from a tracker perspective, I can say that in the large wafer format the Watts per module is high but the number of cells is fewer, leading to reduced operating voltage. This enables us to run much longer strings, up to 40 modules in a string in higher temperature locations which can unlock considerable downstream savings on electrical BOS such as fewer home run cables to make off, fewer combiner boxes to procure and install with accordingly fewer linear metres of DC trenching and so forth.  In markets with higher prevailing labor rates like Australia we’ve found these savings can exceed one cent per Watt peak which has been corroborated by independent third parties.

And in a more general perspective, we foresee 210mm will rapidly gain acceptance and become the preferred choice by customers – given  the higher power bin the modules can achieve with 210mm cell.

Are rooftop solar customers also preferring larger formats?  

This is dependent on the type of rooftops and project sizes. We have customers using the 19 series – up to 550W for their rooftop projects.

As you mentioned trackers, Trina Solar has also introduced two new trackers compatible with the larger formats, are these trackers compatible with larger modules across the industry?

With being a first mover to large format modules, we had early visibility on the module form factor becoming increasingly large, which is important considering the modules are now approximately 20% longer than the 500W ones.  This is pertinent because the module sail area increases and accordingly so does the intensity of the wind loading into the structure given the non linear relationship between wind load and height, which is further accentuated on 2 portrait trackers which sit higher from the ground.

As the only module manufacturer to offer an integrated PV and tracker solution, we were able to spend longer performing our full aero elastic wind tunnel testing regime in conjunction with pre eminent wind consultancy RWDI.  This involved, firstly, ensuring unequivocally that the tracker structure holds up to every possible wind load combination, including complex 2^nd order dynamic effects, which are even more pronounced as string length and therefore tracker length increases. Ultimately, we were able to  completely ameliorate this and ensure our trackers could accommodate these longer 210mm module strings by implementing a multi point drive system.  And then secondly, we were able to implement a value engineering approach to optimise things like material usage, gauge thickness and especially the foundation count, which can now be as low as 100 piles per MW DC, unlocking more considerable savings on sites with challenging geotechnical characteristics and especially so in high labor cost markets like Australia.  All this enables our customers to attain not only super competitive supply pricing but ultimately also lower fully installed turnkey capex.

We also made sure the boundary conditions utilised in the wind tunnel testing were future proofed for future module form factor changes including the recent introduction of 650W+ modules from both Trina and our competitors in the module space.

In the upcoming edition of pv magazine PVInfoLink stressed the importance of innovation in the transport sector, and this week I see Trina Solar has come up with a novel approach for packing modules into shipping containers. Can you tell us about it?   

Conventional loading is based on horizontal placement and 2 stack. At Trina Solar we’ve managed to design a  vertical placement solution for the large size modules so it will fit into the 40HC container with 18 pallets. As with any design improvement or saving on the transport side this solution is will help us save a great deal of money, savings we can pass on to the customer.

The utility-scale solar sector is going big over the next decade, in Asia Pacific especially, what do you see as the major trends that we will continue to see?  

There are a number of exciting and disruptive opportunities in utility solar right now. One topic particularly close to my heart from living in Victoria, which is referred to as the food bowl of Australia, is the potential for dual solar and agriculture, not simply grazing sheep but truly integrated land uses where land owners can create energy as green as the crops they produce, and our trackers enable this Agrivoltaic approach as we have done on numerous Top Runner projects in China.

There’s also much talk about using renewables to create green steel and capitalising on Australia’s abundant natural resources to become an export power house again, and as a father of two young kids the opportunity to create thousands of industrial Australian jobs in the future is very exciting.  On this same note we are exploring local procurement and fabrication opportunities for the tracker steelwork to be locally sourced within Australia.

We are also looking to disrupt the industry on our next generation trackers utilising things such as predictive maintenance for O&M utilising IOT sensors, automated tracker and module assembly.  In terms of the wider APAC region, which historically has preferred fixed structure solutions over trackers, we’ve seen a real spike in interest with the value stacking potential of bifacial PV onto trackers.  And as the bid pricing has continued to decline to the super low pricing we’ve seen in India, we see developers and IPPs who own and operate over the long term truly value the higher and more assured long term energy outcome from a trusted solution provider like Trina, as opposed to opting for lowest capex approaches, and we very much expect this trend to continue within the wider region.