From pv journal 05/23.
It is a declare as outdated as the trendy photo voltaic business: Not all roofs or different surfaces are appropriate for conventional, glass-encapsulated photo voltaic modules. Consequently, particular modules are wanted to beat any obstacles. The merchandise provided embrace a variety of module sizes and dimensions, light-weight variations for roofs that can’t stand up to glass masses, adhesive set up to stop penetration of the surfaces of roof, and even curved or versatile modules that may comply with the contours of the roof.
The logic behind this considering is evident. To realize the targets of speedy and widespread decarbonization, it’s obligatory to put in photo voltaic on as many usable surfaces as doable. To some extent there may be current proof to counsel that that is understood. One instance is balcony photo voltaic, which is changing into extra widespread in Europe as EU states deal with an power disaster fueled by Russia’s invasion of Ukraine.
Going again virtually a decade, the primary photo voltaic expertise that tried to fulfill the necessity for versatile and light-weight functions was skinny movie – copper indium gallium selenide (CIGS) photo voltaic specifically. Producers resembling World Photo voltaic and MiaSolé intend to introduce versatile modules that present comparatively good conversion effectivity – 10.6% and 14.3%, respectively – in a versatile format.
Each corporations struggled to compete, nonetheless, and have been successfully shut down on account of their acquisition, in 2013, of Hanergy – an organization whose shares have been suspended from buying and selling on the Hong Kong alternate for 3 years with out but the enterprise withdrew the inventory and went personal. .
Subsequent-gen flex
What a distinction a decade makes. On the Solarex commerce present in Istanbul, Sunport Energy, a Chinese language steel wrap-through (MWT) producer, showcased its S-Flex module – a light-weight, versatile product that achieves 21.8% effectivity and an influence output of 365 W to 385 W.
“In Turkey, versatile modules are very new so the response has been superb,” stated Sunport’s advertising and marketing director, Katrina Xu, as present attendees stopped by the corporate’s sales space to take a look at the S-Flex. “In March, we have been at Photo voltaic Options and there was numerous curiosity as a result of in Europe the residential market is rising properly. In Germany, they need to use these modules in balcony functions.
This 12 months noticed Sunport emerge onto the worldwide stage after greater than two years of isolation because of China’s strict Covid-19 containment measures. “It’s troublesome for us to go outdoors China,” Xu stated. “With a brand new product, we have to speak on to clients. And for the final three years we’ve not been ready to try this.”
The MWT expertise deployed in S-Flex is a back-contact cell during which laser-drilled holes, or vias, are shaped by the wafer, enabling the entrance metallization to wrap by the opening to the again facet. The cell itself, on this case, is a PERC (passivated emitter rear contact) gadget. The cells are wrapped in a light-weight however robust polymer materials – “2D encapsulation” within the parlance of the corporate – leading to a 5.7 kg module that may accommodate a most bending radius of 0.3 m.
As a back-contact expertise, MWT eschews conventional busbar cell interconnection to as a substitute use copper frontside metallization and a conductive backsheet. “This makes the expertise extra appropriate for versatile encapsulation,” Xu stated. “Once you make the ribbon of the photo voltaic cell, while you bend the module, the welding level has stress that simply causes micro cracks. And the busbar-free design reduces the module shading space to extend the module conversion effectivity. We’ve got self-made copper conductive backsheet. So we do not have welding stress. And in the event you bend it, we do not have issues just like the busbar module.”
Coupling MWT with versatile encapsulation seems to be a neat trick. Suntech pioneer Zhengrong Shi believes this, saying that “as a result of the tabbing is on the identical floor, you do not have to consider bending.” Since 2018, Shi has promoted “glassless” light-weight modules below the Sunman Power model.
Not surprisingly, the 2 corporations are charting the identical course, with Sunport CEO Fengming Zhang the previous Suntech chief scientist and each Zhang and Shi alumni of the College of New South Wales. Shi stated Sunman had shipped 200 MW of light-weight crystalline silicon modules in 2022 and anticipated it to “not less than double” this 12 months.
By way of cargo, Sunport has larger ambitions. The corporate targets S-Flex gross sales of between 300 MW and 1 GW this 12 months. “An important market is Europe however we’re additionally taking a look at Brazil, Japan, and Australia,” stated Sunport’s Xu.
Advantages of back-contact
Conductive backsheets provide further advantages. Endurans, a supplies provider, ships conductive backsheets, primarily to module producers in Europe and North America. Lawrence Theunissen, the enterprise director for the fabric, likens it to printed circuit boards in the best way that it conducts electrons “in response to the format of the cells within the module.” Greater than the versatile modules themselves, this performance offers “flexibility” to module makers, he stated.
“One other approach to take a look at flexibility – and that is one other large good thing about utilizing a conductive backsheet – is to make use of flexibility within the placement of your electrical sample,” he defined. “Often, conventional modules embrace a few strings contained in the module – a matrix format – so it is not sophisticated.”
Conversely, Theunissen says, module producers can counsel Endurans cell configurations and a backsheet materials will be designed accordingly. This may be significantly helpful in rising PV functions resembling vehicle-integrated PV. The Endurans are working with Lightyear, a startup, on the aborted improvement of the Lightyear 0 photo voltaic automobile.
Whereas the Lightyear crew failed of their try and deliver a high-end electrical automobile to market, “they’re making good progress, particularly on the photo voltaic facet,” Theunissen stated. The modules Lightyear developed are curved, matching the automobile’s aerodynamics and aesthetics. In an try and pack such a big energetic photovoltaic space in a restricted area, says Theunissen, “the cells don’t align in a matrix association however in a non-linear approach that easily follows the form of the automotive.”
Lightyear makes use of interdigitated again contact (IBC) cells in its design, as a substitute of MWT, however each are served by a conductive backsheet. The fabric comes with the next value profile, as Endurans acknowledges, however that is compensated by elevated worth creation, the corporate argues.
“For module producers, now we have a transparent indication that the enterprise case will likely be extra engaging than normal modules,” Theunissen stated. “There’s a larger value concerned however the value will likely be larger ultimately market.” The Endurans director added that efforts proceed to scale back materials prices, together with changing the copper backsheet with aluminum.
Questions stay
Regardless of the promise of opening up a wider vary of PV surfaces by new module codecs and back-contact expertise, the area stays a distinct segment. “The explanation photo voltaic is so good is that it is a standardized product that has a very good lifespan, if put in correctly,” stated Jenny Chase, the Swiss-based head of photo voltaic perception at BloombergNEF, a enterprise information firm. “That is what’s going to make the most important contribution to fixing local weather change.”
Chase acknowledges, nonetheless, that vehicle-integrated PV can present a “psychological profit, particularly if it is light-weight. Understanding that photo voltaic will trickle down the cost after I store can provide me peace of thoughts.”
Of the functions that may be addressed by versatile, light-weight photo voltaic, he means that the photo voltaic balcony could signify “the very best of them, as a result of there may be some participation in that.” The benefit of set up additionally offers worth to the business, he stated. “There’s a bottleneck in Europe, to work on the set up.”
For Sunport, the truth that S-Flex will be put in on roofs that use sheet steel, with out drilling holes within the roof, is a plus. “This product may be very appropriate for factories with steel roofs,” stated advertising and marketing director Xu. “In the event you use our versatile module, you may instantly use the glue and put it on. You needn’t drill holes within the roof the place water can get in.”
There are additionally financial savings by way of stability of system (BOS) parts and labor, Xu stated, which offsets the upper panel value – itself a perform of the module’s larger materials value. “In the event you see the full value of BOS – together with mounting programs – with customized modules, and together with human sources for set up, then the price is comparable. We solely use glue , so the general BOS is decrease.
There isn’t a doubt that the again contact expertise, in numerous codecs, is on the map of many module makers – together with the massive producers. Sunport itself plans to launch the following technology of its expertise on the SNEC commerce present in Shanghai final month.
“It is a totally different back-contact expertise,” Xu stated. “The expertise is acquainted to us as a result of it’s a again contact. The floor has no holes, no ribbons, so the aesthetic is superb.
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