Rather than attaching solar panels to a preexisting roof, Seattle City Light (SCL) designed the shelters to be dual functioning, using the modules themselves as the roof structures. Most solar modules are structurally weak and unsuitable to be used as a roofing material. However, the Silicon Energy modules use glass on both sides of the solar cells, forming structurally robust frameless “tiles” that allow light to penetrate around the edges of the cells. Between the overlapping modules, gaskets were attached to block rain blowback from prevailing winds. The picnic shelters were not designed to be waterproof, however, and some leakage around the bedrails or “mounting feet” is expected. If desired, this type of shelter could be more rain tight by installing vertical gutters sandwiched between the mounting feet and steel rafters, diverting all water shed by the shelters into the existing attached gutter at the bottom of the array.
The new SiE5300 inverters are single phase by default and needed to be reconfigured to 208V without a neutral in order to backfeed into the preexisting three-phase SCL service at the park. Custom service cabinets were built by Skyline Electric, located in downtown Seattle, in order to accommodate the ventilation needs of the inverters while protecting the equipment from vandalism (or stray condiments).
Unlike most community solar projects in the state, the Jefferson Park shelters are highly visible and meant to be an integral part of everyday park usage. Jefferson Park users have sought covered picnic areas for more than a decade, but tight budgets had kept the Seattle Parks Department from providing them until now. The Community Solar project was developed with the help of a $300,000 grant from the U.S. Department of Energy. City Light customers can purchase units of the array for $600 each, which in turn cuts down on their monthly utility bill. According to Seattle City Light, most of the 500 units having already been sold, which will create a rotating fund for the utility’s next solar projects in the near future.
“I’m very happy to be a part of this program,” said Robert Hinrix of Beacon Hill, one of the project’s founding members. “I’ve been a longtime supporter of alternative energy, going back 30 years almost. This is a way I can put my money where my beliefs are and make something happen. I encourage all of my neighbors and fellow citizens of Seattle to consider it.”
