In the News: Mabel Rush roof sprouts solar panels

Newberg Oregon School District

Solar panels that have sprouted on the roofs of Mabel Rush Elementary School during the past few months were recently activated and started generating electricity. Nearly 400 panels and reflectors were installed by PGPV LLC as part of the deal where the Albany-based company is renting roof space from the Newberg School District. Company owner Peter Greenberg said the system installed on the roof of the school’s library, lobby and cafeteria is made up of newer, smarter and more efficient panels.

Each panel produces 130 watts of electricity, but unlike older panels where shading an area the size of a credit card would lead to a disproportionately large drop in electrical production, the newer panels can be shaded by as much as 50 percent and still produce 50 percent of their output.

The electronics that control the system are also newer, with each panel optimizing its energy-producing performance instead of an inverter looking to optimize the weakest panel.

The roofs of Mabel Rush proved to be a challenge, Greenberg said. He had originally hoped to install the panels on the flat roof of the gymnasium, but engineering studies indicated that the weight of the panels would be too much for the aging structure. An installation in a grass courtyard on the back of the building was also nixed.

To increase the performance of the panels, PGPV installed specially designed reflectors that bounce additional light into the panels without generating more heat. High heat, mostly in the summer, reduces the efficiency of the system. As such the panels “use an aluminum back plate to dissipate heat more efficiently,” he said. The reflectors have an orange tinge and Greenberg said newer models are completely clear.

Even on overcast days the panels will produce electricity. Over the course of one year Greenberg expects the system will produce slightly less than 70,000 kilowatts.

School district business manager Nathan Roedel wrote in an e-mail that the district will be paid 39.6 cents per kilowatt hour for a total of $6,600 annually for the Mabel Rush system. A second, larger array will be installed at Newberg High School and earn 31 cents per kilowatt hour for a total of $15,600 per year. The lease has a 15-year term, after which the panels will become the property of the school district. In addition, Roedel expects that the district will save about 400,000 kilowatt hours once the system becomes school property and save $40,000 annually.

The high school system will be installed after engineering studies are finalized.

Story and photo by Laurent Bonczijk, the Newberg Graphic