Meyer Burger’s (SIX Swiss Exchange: MBTN) patented SmartWire Connection Technology (SWCT) for solar cells achieves higher efficiency solar modules and reduces production costs in PV manufacturing. Solar cells are electrically connected using thin copper wires on both sides of the cell thereby replacing the classic 2 to 3 busbars. Typically, 30 very fine copper wires are used for cell connection generating up to 2,000 contact points per cell.
SWCT’s fine copper wires reduce shading on the solar cell by 3% in comparison to cells with 3 busbars. Coupled with its 2% lower series resistance, SWCT technology increases the power output of a solar module by 5%. The round copper wires used in SmartWire technology increase the amount of sunlight reflected onto the cells resulting in SWCT contacted modules beginning to produce electricity earlier in the day and stop producing electricity later in the day. This leads to an increased energy yield of about 10% (kWh/kWp) compared to busbar technology. SWCT increases cell stability and reduces the impact of possible micro-cracks on the power of the solar module. Micro-cracks are the most common cause of energy loss in solar modules
The proven SWCT technology significantly reduces the cost of production by eliminating the busbars on both sides of the cell and optimising finger widths thus reducing silver quantity by up to 80%. Based on the current price of 30 USD/troy ounce for silver, this reduction in silver results in up to 0,25 USD/cell lower material costs.
SWCT is compatible to all crystalline silicon cell technologies: selective emitter, PERC and Heterojunction (HJT) in both p- and n-type silicon cells. Wafer thickness can be as low as 100 µm and thinnest finger widths can be used in SWCT technology. This very future oriented technology can also be applied to the next generation of finger metallisation technologies.
Heterojunction (HJT) cells are very sensitive to high temperatures above 180°C that are typical of traditional busbar soldering. The innovative SWCT copper wire process takes place at lower temperature which not only enables contact to be made with high performance HJT cells, the lower temperatures further reduces energy costs during module production. Modules combining HJT cell technology with the SmartWire Connection Technology have achieved active area efficiencies of over 20%. The SWCT process is self-aligning and omits complicated ribbon lay-out on the contact surface of the cell.