Introduction
The annual SNEC PV Power Expo in Shanghai, China, is now the largest solar energy exhibition worldwide. We came by at the Shanghai New Int’l Expo Center for a look at the latest solar products, technology trends and to meet friends in the industry.
The past 6 years we have been visiting this exhibition, either as exhibitors or visitors.
So what were the top 10 product and technology trends of SNEC 2015? We like to share what caught our attention:
1. Higher module rated power output
An obvious trend is the production of modules with higher rated power output. While 250Wp solar modules are still the most common output types of modules you can find in installations worldwide, the trend is going towards solar modules with higher rated power output.
Main triggers of this trend:
- Space limitations at installation sites, constraining efficient string sizing of a PV array
- Aim for higher power yield/ square meter
- Increased power output at minor voltage/ current increases
Most of the big and also many medium-sized solar module manufacturers presented their 300Wp, 350Wp… and even 500Wp modules, some of them though at the expense of larger module sizes, thus actually nullifying the core advantages of producing modules with higher power output…
2. Light trapping from DSM
AR coatings are now used on the majority of solar panels and is a proven way to optimize the efficiency of solar modules and therefore reduce the energy costs per unit (Wp).
We visited DSM booth to learn more about their new Light Trapping technology, which they’ve been working on since the company acquired SolarExcel in 2013. DSM claims with this technology the additional energy harvest of PV projects can go up by approximately 6% to 12%. Also the coating could be applied to existing projects which would make the market for this product significant. Unfortunately nobody on the booth was able to tell more about this product yet. Hopefully more info at Intersolar Munich.
DSM already has an AR coating on the market which they call KhepriCoat®. This coating can be applied by the PV glass manufacturer.
With a power gain over uncoated modules of around 3%, such an AR coating has proven to be cost effective.
The downside of additional coatings is the risk of being scratched, even though this particular coating has been pretty well tested during accelerated aging tests (climate chambers), which at least proves it will stick! Interesting PPT on Khepricoat here.
3. PID-tested modules
PID (potential induced degradation) is the current quality bogeyman in the solar module manufacturing industry and it is no surprise that PID and the containment of it was a topic at this year’s SNEC.
Many module manufacturers advertised their modules as PID-tested, sometimes with even clear and big, eye-catching “PID TESTED” or “100% PID FREE” stickers to put the minds of their (prospective) clients at ease… but, can such PID-free claims even hold true?
Canadian solar module
Currently, there is no common established testing standard for PID available. Although the International Electrotechnical Commission (IEC) has been working on a testing and certification standard – IEC 62804 – it is still not fully finalized. Most manufacturers promoting their modules as PID-free have in that regard either contracted the services of a testing lab that – according to its own standards – tested and approved the manufacturer’s module, or the manufacturer itself performed in-house PID testing based on manufacturer in-house standards.
This is far from a common line, so with the so called PID tested/ PID-free modules it comes pretty much down which manufacturer’s claims or which labs you actually believe. Without an understanding about the technical aspects and quality impacts of PID and due dilligence about these diverging standards, it is hard for buyers to evaluate the validity of all these so called PID-free modules…
And, with PID being geared to multiple environmental, material and system factors, it may take years to even make a proper comparison, provided the manufacturer still exists then…
4. Colored Cells
With solar energy increasingly becoming a standard electric commodity in our daily lives, there is more and more demand for sexy, fashionable solar products with attractive designs and looks. An obvious trend in this regard, also mirrored by the products presented at the SNEC 2015, is the increasing product portfolio of colored modules and cells.
Even though still comparably rare and more expensive than standard-color solar cells, several companies such as Sunways, displayed colored-cell products in their product portfolio at the SNEC, though none company we visited had tangible product samples available on-site.
Sunways’ colored cells for BIPV systems
While monocrystalline cells are typically blue, black or grey and poly crystalline cells usually blue or dark blue, manufacturers of colored cells – the majority of those few located in Mainland China and Taiwan – resort to varying the thickness of the anti-reflection coating to change the color of the cells. Even though looking nice and especially attractive when using with color-compatible modules and consequently installed on color-compatible roofs, however, this adjustment comes at the cost of the cell efficiency which will decrease by 15-30% depending on the color.
As colored cells come with lower efficiency as compared to their traditional counterparts, some manufacturers offer alternatives in form of for example full-black modules.
5. SmartWire from Meyer Burger
Meyer Burger’s claims its SmartWire Connection Technology (SWCT) is now the most cost effective method of stringing solar cells. Say goodbye to the good old tab wire?
Meyer Burger Smart Wire Technology
Instead of using standard tab ribbons, the company uses a foil-wire electrode.
A number of advantages:
- No need for manual or automatic soldering
The company is combining solar panel lamination and cell interconnection in one single step. To us this is the biggest plus of SmartWire.
The foil-wire contains low temperature melt solder, which will connect to the solar cells during lamination. - Improvement in efficiency due to reduced shading
The gain is about +3% efficiency compared to 3 busbar connection. - Fewer use of silver
Busbar printing can be avoided, which means a reduction in silver use. - Effects of micro cracks are reduced to a minimum
Due to the larger number of connections, a micro crack doesn’t mean you’ll lose part of the solar cell’s performance. See an example here of an EL image:
Meyer Burger Smart Wire – EL image
SmartWire Connection Technology Fact Sheet here
A number of small manufacturer have started using SmartWire technology. If this new way of cell interconnection is reducing cost, why isn’t every manufacturer using it yet?
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6. Cell-level smart modules
With the solar module manufacturing industry in 2015 still being strained by overcapacity, non-innovative and all-similar mass products with similar technical vulnerabilities, one company stood particularly out with its products at this year’s SNEC.
The US-company tenK Solar, which also has manufacturing operations in Shanghai, China, produces solar modules that are tolerant against shading, hot spots and other cell-level failures that usually come with traditional solar modules. Based on patented manufacturing technology, the electrical current in tenK solar’s modules can flow any direction and can thus circumvent a shaded or dysfunctional cell, thus isolating cell-level defects from the other cells of the module.
tenK’s modules are low-voltage, thus significantly reducing safety risks such as flash arcs and electrical shocks and also come with integrated ground fault detection circuit.
The company also produces offers fully integrated PV system solutions with promising yield and performance claims. TenK’s products and its application in projects worldwide are certainly a must-observe in future…
500W tenK solar module
7. Charge controller mobile monitoring
The integration of solar with information technology is progressing. Not only can the operational functionality of modern inverters or whole PV system performances be tracked via internet, but also the operations of charge controllers be handled via mobile applications.
The Beijing-based manufacturer EP Solar presented new models of its charge controller lineup during SNEC 2015, featuring convenient charge controller operation and monitoring via smartphone. While an IR (infrared) plug-device that communicates with the charge controller is plugged on the mobile, EP solar’s internally developed mobile app accesses the infrared connection devices, operating and monitoring the charge controller at a distance of at least 10-20 meters.
At SNEC we had the chance to experiment with the app and the connection device. Optimally the phone with the plugged device are rather straightly pointed towards the charge controller in order to ensure good connection.
Currently, EP Solar’s charger controller mobile feature is only available for iOS devices, however EP Solar explained that versions for Android devices were already in development.
EP Solar charge controller monitored and operated via mobile app
8. New types of solar module frames at SNEC
A couple of companies were displaying new frames:
Canadian Solar – polymer thin frame, model CS6K. This is a double glass module. It seems most manufacturers are not 100% confident about frameless double glass modules. Canadian Solar uses a polymer thin frame. Advantage is that no grounding is needed, and removing the conductive frame also eliminates the cause of PID.
Suntech carbon frame
Suntech, part of the Shunfeng group, presented its new frame which is made of a carbon material. It’s about 25% lighter weight. It has the same advantage as Canadian Solar’s module above: no grounding needed.
9. Mounting without clamps, DuPont’s Polymer Backrail System
The trend of using frameless double glass solar modules is continuing and DuPont showed its Polymer Backrail System solution.
The Backrail is applied with an adhesive. It looks neat..
Dupont Polymer Backrail – back solar module
Dupont Polymer Backrail – side view
Dupont Polymer Backrail – mounted solar module
The company has passed 5400Pa mechanical load testing with this setup, even though it look a lot less steady than a framed glass module.
Anyone working with adhesives knows it’s essential to work in a clean and dust free environment when gluing anything together. We believe the best moment to adhere the Backrail to the solar module is at the PV factory.
Anyone experience yet working with this mounting system? Drop us an email!
10. Hanergy.. Anything new from the ‘most valuable’ solar manufacturer in the world?
Not really..
Hanergy at SNEC 2015
The company recieved a lot of attention at SNEC 2015.
It does look impressive to see all those acquired technologies together on one booth: Miasolé, Global Solar, Alta Devices, Solibro… did we miss any?
Hanergy at SNEC 2015
Hanergy has received plenty of criticism and doubt about its current business practice. The company’s HK listed entity soared sixfold in a year, which makes it the most valuable solar manufacturer in the world.
The past months Hanergy has received lots of criticism:
WSJ: “Hanergy is still a head scratcher”
Reuters: “Thin-film solar technology under scrutiny as China’s Hanergy soars”
GTM: “Unconventional accounting from Chinas Hanergy”
No comments here as we’ll dedicate a special on Hanergy later.
Andrew Ye
on 24 Jun 2015Dricus
on 25 Jun 2015