New PV Cell Vibration Test Method Task Force Formed
Catherine Chang, Senior Manager, Standards and Technology, SEMI Taiwan
The PV industry is expanding rapidly to meet growing renewable energy demands worldwide, and Taiwan is a leading country in PV Module production. To reduce the failure rate for system users, the Taiwan Photovoltaic Committee already has a task force developing a module vibration testing method, and a new PV Cell Vibration Test Method Task Force was recently formed.
For c-Si technology, one of the current technological challenges is identifying and eliminating the sources of mechanical defects, such as thermo-elastic stress and cracks. These defects lead to the loss of wafer integrity, and ultimately, breakage of as-grown and processed Si wafers and cells. A significant challenge in using thinner crystalline silicon wafers for solar cell manufacture is reduced yield due to increased wafer breakage. Shipping and packaging damage is always one of the top causes of the PV failures in the field. The cell breakage mostly depends on the stresses induced in the processing, handling and transportation, and also depends on the presence of defects such as cracks.
This goal of this activity is to provide a test method to evaluate the defects on PV cells due to stress during transportation. These stress factors due to environment are vibration and temperature, and transportation vehicles will include trucks, trains, aircraft, and ships. The activities of the task force will result in the development of an industry standard where equipment suppliers, cell manufacturers, module makers and other involved parties can find conformity, in any technical field of PV cell reliability.
When this document is published, cell makers and buyers will have a common testing standard to reference. In addition, the Committee expects this standard to also aid acceleration of development of cell protection design during transportation as well.
For more information on PV Standards activities at SEMI, please visit: www.pvgroup.org/standards.
SEMI Standards Watch – April 2011