During 2014, 89% of cable systems installed at utility-scale renewable energy sites in the U.S. met the manufacturers' quality control standards on the initial test, according to Manchester, Conn.-based IMCORP, a diagnostics services provider for underground power cables.
The cable system quality rating for the U.S. renewable industry was 84% in 2013. Although the performance increase is small, it does end a negative trend that occurred in 2012 and 2011.
IMCORP assesses thousands of new cable systems annually and maintains a database of medium- and high-voltage cable installation performance data.
As part of its testing, IMCORP performs what it calls a factory-grade test to assess the condition of each cable system allowing for pre-energization repairs of substandard components. The factory-grade test locates existing cable system defects and predicts future cable reliability of new or aged cable systems from 5 kV to 500 kV, IMCORP notes.
According to IMCORP, the average facility is at risk for 11 cable system failures before the end of its designed life. Therefore, renewable energy site owners that use the factory-grade test are able to locate, mitigate and avoid outages associated with these embedded defects that may occur after manufacturing or during installation.