Solar groves are cropping up in the region, their canopies providing power for businesses and shade for employees' cars from above San Diego parking lots.
A Solar Grove consists of a series of steel-framed structures supporting photovoltaic solar panels, called solar trees. The structures are aligned like real trees, providing filtered shade throughout the day for cars parked beneath them.
The Solar Grove is currently a trademark of Kyocera, however Envision Solar, which engineers and installs the structures, has filed to have the trademark transferred.
The first Solar Grove was installed in 2005 at Kyocera's national headquarters in Kearny Mesa. The grove covers 186 parking spaces and generates 431,000 kilowatt hours each year.
The project was so exciting to the two architects at Tucker Sadler who designed the Solar Grove, that they left the company to form Envision Solar, said Pamela Stevens, Envision CEO. The start-up solar company has steadily grown, offering various types of solar installations. Thus far Envision's most popular design concept is the Solar Grove, which they have installed at businesses, universities and hospitals state-wide.
Envision's most recent Solar Grove installations in San Diego are atop UCSD's Gilman and Hopkins parking structures. The project is expected to be completed in November and will generate 200 kilowatts from the Gilman structure and 340 kilowatts from the Hopkins grove, said Dave Weil Director of Building Commissioning and Sustainability at UCSD.
The two solar groves were installed through a power purchase agreement. The financing arrangement allowed UCSD to pay nothing for the installation and purchase the power as it is generated. After putting out a bid for a solar installation, the university chose to work with Borrego Solar, Solar Power Partners and Envision Solar who bid to install a Solar Grove. Although the university was not specifically seeking to install a Solar Grove, they are very happy with the result, Weil said.
"We think the Solar Groves have advanced the appearance of the structures," Weil said.
The Solar Trees provide UCSD the added bonus of housing chargers for electric vehicles in the base of each trunk. The Gilman and Hopkins parking structures already contain chargers to re-energize the university's more than 300 electric vehicles. Weil is excited about the possibility of moving the existing chargers into the trees to power electric vehicles with the sun, he said.
"Its really worked out well," Weil said. "It's a big part of our sustainability program."
People were not always so optimistic about the future of Solar Groves. When Envision began marketing the idea it was met with skepticism, Stevens said.
"When we first started going to solar shows and talking about parking lots we were laughed at," Stevens said. "People thought we were nuts."
When solar technology was first introduced to the market, most consumers considered it a blight that should be hidden away on rooftops, Stevens said. Envision had the opposite attitude toward solar.
"We believed that solar was beautiful," Stevens said.
More recently consumers have been adopting Envision's mindset, wanting to show off their solar panels in places with high visibility. The Solar Grove has become popular in part because of its high visibility, Stevens said.
Other recent installations include ResMed in Poway and a breadth of other projects at hospitals and businesses throughout the state. A Solar Grove is also planned for the parking lot at Mesa College in Mira Mesa.
Energy generation aside, the Solar Grove has cultivated interest due to the host of other benefits the design offers. The trees increase security by housing lights while reducing light pollution with its cover. The trees also help to route rainwater runoff into bio-swales, where the water is filtered before trickling back into the soil. Envision also sees the potential for the groves to help reduce the urban-heat island effect by shading large areas of asphalt.
Such factors make Solar Groves ideal for urban environments and a potential source for distributed generation, Stevens said. Parking-lot sized installations are ideal to power individual businesses and communities.
"I think these are absolutely the best vehicle for distributed generation," Stevens said.