Summary
The Fraunhofer Institute for Solar Energy Systems (ISE) in Germany, in collaboration with Comax, has developed a groundbreaking technology for connecting high-efficiency MWT (Metal Wrap Through) cells. This innovative approach offers significant cost advantages and minimal energy losses, making it a promising solution for the next generation of solar modules.
Introduction
In today’s fiercely competitive solar energy market, PV module manufacturers are constantly seeking ways to stand out. The primary goal is to achieve the highest possible module efficiency at the lowest possible cost. While many companies claim to have mature products, most fail to deliver on their promises when subjected to detailed analysis. There are numerous examples where technological advantages in one area do not translate into real-world benefits for the final product. For instance, reducing cell costs may not lead to lower module costs, or improving cell efficiency might not result in a proportional increase in module efficiency.
The Challenge of Cell Interconnection
When connecting solar cells to modules, there's a fundamental trade-off: to minimize current loss from the cell to the module (CTM), the cross-sectional area of the interconnecting ribbons or wires must be increased. However, to reduce the shadow effect on the front side of the cell, the cross-sectional area should be as small as possible. Using multi-strand wires instead of traditional ribbons helps mitigate this issue but doesn't fully resolve it. This dilemma affects all types of front-contact cells, such as BSF, PERC, and HIT. Only back-contact cell technologies, like IBC, EWT, and MWT, can eliminate this problem entirely by allowing large cross-sectional connections without any shadow on the front surface.
Because of this, back-contact cell technologies are becoming increasingly attractive for improving both cell and module efficiency. These designs enable low CTM losses and no front-side shading. While conductive backplanes make large cross-section interconnections possible, the industry continues to search for a low-cost alternative that achieves similar performance.
A New Connection Technology
Comax, in partnership with the Fraunhofer Institute for Solar Energy Systems, has introduced a new interconnection method known as HIP (High-Efficiency Module) technology. This approach combines traditional ribbons with an innovative cell interconnect design. The technology has been independently verified for its ability to reduce CTM losses and improve module power output.
One of the key advantages of HIP technology is its low material and equipment costs, with CTM losses potentially below 1%. At SNEC 2013 in Shanghai, Comax will showcase standard 60-cell modules made using this new technique at Booth No. E3-520. During the event, Comax and the Fraunhofer Institute will demonstrate the clear cost-per-watt advantage of the HIP technology.
Additionally, the production of high-performance MWT cells and HIP modules can be carried out on both existing and new production lines. The necessary technology, equipment, and materials are all available. Compared to other emerging solutions, Comax’s approach requires minimal changes to current manufacturing processes and incurs little additional cost. This makes it easier for module manufacturers to transition to more efficient products quickly, giving them a competitive edge in the market.
WENZHOU FOREVER CLASSIC TECHNOLOGY CO.,LTD , https://www.fosicvalve.com