Module output key to lower cost
Solar PV manufacturers are switching over to higher efficiency monocrystalline cells to increase power output, but for solar energy systems, overall module output is key. "In order to balance costs and the power efficiency of solar systems, it is important to reduce CTM (cell to module) loss as well as place greater emphasis on module assembly technology and materials application," said Jason Huang, research manager at EnergyTrend, a division of the Taiwan-based market intelligence firm TrendForce.
A number of solar PV firms are working to bolster module output. For instance, SunEdision has developed zero white space (ZWS) technology that boosts performance by optimizing the solar module itself. ZWS utilizes the area between cells, eliminates losses from bus bar shadowing, and reduces electrical losses. That reduction in losses and additional active area generate higher power output. Other solar firms are using larger silicon wafers and more efficient cells, such as Komax Solar. Its HIP module has a larger area than a typical module and uses shading reduction to enhance output.
Module power output of 60 pcs of polycrystalline cells is primarily 250W and 255W. But there is a new 300W module available that offers many advantages. Winaico's 300W module adopts the M1 mono-si wafer, which is larger than the traditional P-type mono wafer, and uses PERC technology. Along with special conductive pads with LCR (Light Capturing Ribbon), this technology can effectively reduce efficiency losses in the assembly process.
By balancing module output and overall system cost, it is possible to both use expensive high-efficiency cells and reduce other costs associated with solar systems such as brackets, cables and land area, Huang said. "The high-wattage 300W output module offers an opportunity to reduce system costs 5-8% from the current mainstream 250W module," he said. Currently, modules account for 28-35% of the overall cost of a solar system, so boosting module output can result in significant savings per system unit. Cost advantages to higher output modules are especially evident in markets where labor costs are high, such as the US and Japan, Huang added.
