Sun Light & Power: San Jose Environmental Innovation Center

The San Jose Environmental Innovation Center (EIC) brings environmental and economic benefits to the region. The facility itself is a showcase of energy- and water-efficient practices and is home to three tenants: Prospect Silicon Valley, a technology demonstration center; a Habitat for Humanity ReStore; and a county collection center for household hazardous waste. Adding solar to this state-of-the-art facility was a logical step to achieving the center’s sustainability mission and a net-zero building. Instead of allocating money and resources toward constantly escalating energy costs, the center can instead focus on its regional mission to support San Jose’s green vision goals by helping to create clean-tech jobs, to reduce regional per capita energy use by 50%, to build or retrofit 50 million square feet of green buildings, to recycle or beneficially reuse 100% of wastewater, to divert waste from landfills and to replace San Jose’s streetlights with zero-emission lighting.

A 6,600-gallon water storage tank collects and stores rainwater captured from the facility’s watershed—its roof. EIC uses this water to irrigate a grove of 100-year-old olive trees. Sun Light & Power is particularly fond of this project, not only because of the challenge it posed and the success attained in its design and workmanship, but also because the PV system supports a center that represents the company’s values of community, environmentalism and sustainability.

The Center’s designers went to great lengths to make the facility solar ready in anticipation of installing this system. As often happens, these efforts had mixed success. On the one hand, the team made the interconnection of sixteen 4/0 conductors to the supply side of the existing main switchboard significantly easier by preplanning for sufficient lugs in the appropriate location. On the other, the construction crew did not properly locate or mark the spare underground conduits out to the parking lot, and they buried the stubs below grade, so it took significant time to discover, expose, identify and retrench those conduits to make them usable.

The flat-roof portion of the project had existing stanchions that the construction crew had installed and waterproofed for the PV system. However, the stanchions were spaced 19–21 feet apart, much too far for an off-the-shelf PV racking system. A custom, multilayer W8x18 beam and purlin structure (as opposed to a truss system) was necessary to maintain a low profile and to achieve the spans that the existing stanchion spacing required.

In the same spirit of preparing for the future, Sun Light & Power designed the PV system for a planned addition of 100 kW of solar capacity. The team installed five 20 kW inverters and associated ac wiring for that expansion. Sun Light & Power also up-sized the PV inverter accumulation panelboard and associated feeders and interconnection equipment to include capacity for the addition.

“It’s exciting to see how bright green San Jose can be!”

Bailey Smith, Sun Light & Power

“Sun Light & Power had the best proposal, experience and expertise to complete the project to the City of San Jose’s high standards. It’s rare to meet a solar company that has lasted so long. The savings greatly reduce the overall operating costs of the center.”

San Jose Environmental Innovation Center

Overview

DESIGNER: Ivy Dwiggins, project engineer, Sun Light & Power, sunlightandpower.com

SUPERINTENDENT: Bailey Smith, PV and solar thermal superintendent, Sun Light & Power

LEAD INSTALLER: Jack Lai, PV foreman, Sun Light & Power

DATE COMMISSIONED: July 2016

INSTALLATION TIME FRAME: 90 days

LOCATION: San Jose, CA, 37.3°N

SOLAR RESOURCE: 5.15 kWh/m2/day

ASHRAE DESIGN TEMPS: 90°F 2% average high, 32°F extreme minimum

ARRAY CAPACITY: 381 kWdc

ANNUAL AC PRODUCTION: 563 MWh

Equipment Specifications

MODULES: 1,164 SunPower SPR-E20-327-COM, 327 W STC, +5/-3%, 5.98 Imp, 54.7 Vmp, 6.46 Isc, 64.9 Voc

INVERTERS: 3-phase 277/480 Vac service, 21 SolarEdge SE20KUS, 20 kW rated output, 980 Vdc maximum input, 1,164 SolarEdge P400 optimizers (one per module), five of 21 inverters installed for future expansion 

ARRAY: 33–37 module source circuits (36 or 37 modules typical), P400 optimizers connected in series with Voc of 1 V per optimizer, operating voltage nominally 840 Vdc (set by inverter), 15 A maximum optimizer output current, two source circuits per inverter, source circuits terminated at inverter wiring box with no external combining

ARRAY INSTALLATION: Three array types: 1) new custom solar shade structures over the parking lot, three structures with 216 modules each, 648 modules total, 230° azimuth, 5° tilt; 2) new custom wide-flange beam structure on flat roof, IronRidge XR-100 rail, 181 modules and provision for 306-module future expansion, 230° azimuth, 5° tilt; 3) flush-mount standing-seam metal roof, S-5 clamps, IronRidge XR-10 rail, 335 modules, 140° azimuth, 5° tilt

SYSTEM MONITORING: SolarEdge SE1000-CCG-G plus weather station, building demand monitoring, custom DGLogik interface with existing building management system and custom touch-screen kiosk

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