Apart from the technology, PSE&G also liked that Petra's system took advantage of existing infrastructure—thousands of readily available poles, Powers says. This would help the utility more readily meet state-mandated quotas for renewable energy.
Two-person installation teams from Riggs Distler & Co., Cherry Hill, N.J., have worked on the project from the beginning. A pole, which usually stretches about 40 ft high, is divided into zones, and panels must be installed only in the "neutral" and "common" zones, or away from the top-most, higher-voltage sections. "As you go higher up the pole, the safety requirements increase because you're working with higher voltages and currents," Powers says.
Panels must be placed higher than 14 ft to ensure they are out of the way of passing vehicles. They must also face south without shading obstruction, and they may not obstruct cable or telecommunication equipment or other devices on the pole.
Riggs sends about 30 teams to install about 10 systems a day, and so far has installed about 155,000 panels. The crew was taken off the job for a few weeks after Superstorm Sandy to help with recovery efforts, Powers says. Downed trees from the storm destroyed about 100 panels, which are rated to withstand winds of up to 120 miles per hour, or a Category 2 hurricane, "but we've never had one fall off a pole," he says. Riggs was released from storm restoration work in mid-November and shortly afterward resumed work on the solar project.
Meanwhile, both PSE&G and Petra continue to gain attention for the program. The two firms, in partnership with the University of Central Florida, PEPCO Holdings and BP Solar, won a $2.8-million Dept. of Energy award in 2010 to expand microinverter system technology to higher voltage operations.
Petra, whose staff grew from 15 initially to more than 150 since it won the PSE&G contract, has also received other DOE awards and has several international smart grid projects under way, including in Jordan, where Petra is working on the largest rooftop solar deployment worldwide.
Kuran acknowledges that there are other utility-scale solar projects larger than PSE&G's pole-mounted program, but "from a distributed fashion, this remains the single-largest photovoltaic distributed project in the world," he says. Simply put, he adds, "We are a powerplant."