Solar industry leaders gathered in San Francisco this week to focus on the growing need for systematic and standardized operations and maintenance services, without which performance readily drops by 10 to 30%, according to Rue Phillips, the CEO of True South Renewables.
A key speaker at the Solar O&M North America conference here, organized by Rotterdam-based Solarplaza, Phillips pointed to the commercial segment of the U.S. solar industry as the worst at O&M practices. Once a panel or wire failure occurs, a string inverter can go down, reducing performance drastically, he points out.
"The big chains are the worst. We literally have found trees growing out of solar modules on commercial rooftops. These companies are being told that their PV systems wont break down and thats not true," says Phillips. His Huntington Beach, California-based company, which claims to be the leading independent solar O&M service provider in North America, advocates that businesses routinely budget 2 percent to 3 percent of their solar revenue stream to an O&M program.
However the most critical period for solar O&M is during the first two years, Phillips emphasizes. We recommend that one and two years after installation, a PV system should be recommissioned completely, to find problems early, he says. Once the second recommissioning has taken place, a PV system owner can be more assured that problems will not arise, and can thus plan less rigorous annual service.
"Utility scale plants have a different approach to O&M: they have an engineer on staff full time. But large commercial and residential developers today typically use the installing company to perform the O&M, even though it requires a different skill set," Phillips says.
Among standard O&M tasks that residential or commercial PV system installers may not be trained to perform are infra-red examinations, IV curve testing, and intermittent ground tracking by wetting down a system, among other tasks.
Problems that may be encountered on these systems can include: extreme weather; module soiling; communication errors; wires or connectors loosening; vegetation overgrowth; rodent infestation; intermittent ground faults; vandalism, structural vibrations and movement; flooding and other electrical component failures, Phillips says.
While True South alone maintains some $4 billion worth of U.S. PV systems spread out over 1,750 different sites, there is still a lack of best practice O&M in the industry, Phillips says. His company performed a side-by-side test of O&M value at two Southern California Edison PV plants in 2009, doing no service on one and performing full service on the other. The results of the test showed that the unit receiving maintenance yielded 14 percent more energy.
"What impressed me at the conference, however, was the degree to which industry leaders agreed that after putting billions of dollars into the industry, it has to be maintained. Thats it in a nutshell," he summarizes.