In the year 2018, a 300 MW solar PV tender in Saudi Arabia rejected what was then the lowest bid offered by Masdar and EDF consortium, preferring the second lowest-cost best bid from a consortium led by ACWA power and Marubeni to award the project to. An energy reporter back then stated Masdar offering to build the project with bifacial modules as one of the factors for their rejection since there wasn’t much knowledge or experience of using this technology (see World’s Lowest Solar Bid Disqualified).
Cut to year 2021. Bifacial solar has grown in stature as well as bankability. Today almost every solar manufacturing company worth its name ensures its product portfolio offers bifacial solar panels to customers who are increasingly growing fond of panels that offer them energy yield from both sides. However, there is still scope for improvement for this technology as TaiyangNews found out during our 1st virtual conference on bifacial solar module technology on March 4, 2021.
Bifacial solar report launch
Titled Bifacial Solar—How to Benefit Most from Generating Power on 2 Sides, the conference was a launch event of our Bifacial Solar 2021 Report whose 1st part was officially released by TaiyangNews PV Technology Expert Dr. Olga Papathansiou. The report Bifacial Solar Technology 2021 – Part 1: Cells & Modules discusses the manufacturing side of bifacial PV technology covering notable developments in cell and module manufacturing. The report is available for free download on our website.
The authors of the report state that PERC is currently the driving engine for these modules, but the biggest hurdle for bifacial PV system designers are accurate energy yield predictions that assume importance for the project’s financing and safety reasons.
TÜV Rheinland’s Project Engineer Ansgar Delahaye offered an overview of bifacial module and system performance from the testing agency’s side in his presentation and covered all existing testing parameters available currently to measure the performance gain expected of bifacial modules. He did add though that it is time to have a new definition of test process and rating criteria for an in-depth understanding of this technology.
Representing the solar module manufacturing segment, Senior Product Marketing Manager of LONGi Solar, Jason Yan stressed on the need to design reliable bifacial solar modules since these would contribute to lower LCOE for end consumers. He pointed out that among other factors, the size of a bifacial module should be a significant consideration since it can put stress on materials, while adding economical, reliable, and high energy yield form the basic design direction for bifacial modules.
Chinese solar cell producer Aiko Solar’s Senior Overseas Sales Director Vincent Lau discussed how to tweak PERC cell technology for high bifacial yields during his presentation, and pointed out that large size cells are born with bifacial features. Bifacial and large size mono PERC cells accounted for over 90% of the company’s shipments in Q4/2020. Going forward, he said in March 2021, the company will bring out dark/black cells for all cell types for aesthetics, while ensuring efficiency, following these with implementing thin wafers for all cell types in April 2021. Aiko targets a cell production capacity of 36 GW by end of year.
On the module BOM side, encapsulation to be precise, Hou Hongbing, R&D Manager of the world’s leading solar EVA foil producer Hangzhou First,  argued that bifacial solar modules will take over the market in the future. Currently P-PERC is the ruling cell technology for bifacial solar modules, he believes the future may belong to N-TOPCon and HJT technologies. While listing different packaging solutions for various bifacial modules, Hongbing batted for transparent backsheet for bifacial module package citing similar optical property it has, compared with glass and comes with good humidity resistance.
Presenting part of the BOS side of bifacial solar systems, the Head of Utility Business at Solis USA, Gary Lam listed innovative system design for bifacial solar modules using string inverters, while presenting details on the company’s 255kW utility inverters as working best with bifacial modules.
Offering ground zero view of deploying bifacial modules on site was Tomaso Charlemont, Global Solar Procurement Leader of UK based solar project developer RES Group, who said his company’s current bifacial project portfolio exceeds 2.2 GW with the majority located in the USA, and much more expected to be commissioned between now and 2025. While hailing the technology for bringing in the LCOE benefits, Charlemont pointed out the onsite challenges faced by developers when using this module technology since it ‘bears a considerably higher amount of variables, all influencing energy production’. He called for focus on bringing in installation best practices and accounting for construction and testing uncertainties.
Dr. Radovan Kopecek, Managing Director Advanced Cell Concepts and Member of the Executive Committee at research center ISC Konstanz presented his conclusions for the bifacial modules and systems. He stressed that the best module is not the one with the highest bifacial factor, but the one that leads to the lowest LCOE—for a given system configuration. Offering his vision for this technology, Kopecek said he would like to see bifacial solar panels, which he sees essential for cracking the 1 US cent/kWh LCOE level, even making their way to space soon as well.
Saving best for the last, TaiyangNews Managing Director Michael Schmela pulled Kopecek in a ‘Fire-Chat’ style Q&A  on bifacial solar modules, bringing forth interesting and quick insights into the technology and its future. Conference recordings are available on our YouTube channel.
TaiyangNews Conferences will be back on April 13, 2021 with yet another virtual event, this time on Solar Trackers. Stay tuned!