Borrego Solar: Newport-Mesa Unified School District

The Newport-Mesa Unified School District (NMUSD) covers nearly 60 square miles in Orange County, California. On September 9, 2014, the NMUSD Board of Education approved the installation of solar carports and lunch shelters, as well as a few small rooftop PV arrays, across 32 sites within the district. The board selected Borrego Solar to lead the overall project design, engineering, construction and ongoing O&M services. From an economic standpoint, the district’s primary goal was to reduce energy costs and mitigate the risk of volatile utility rates over the next few decades. The PV installations are net metered, and each school uses the majority, if not all, of the solar energy generated by its respective PV system.

The district leveraged state incentives and loans to secure its PV systems with little capital expenditure up front. The NMUSD did not use any general funds capital on this project, leaving financial resources available for classroom expenses, and paid for the $13 million project with a $3 million interest-free loan from the California Energy Commission, $5 million in funds from the California special reserve funds for capital outlay and $5 million from California’s Proposition 39. In addition, the district will receive a performance-based incentive from the California Solar Initiative program for the first 5 years of system operation. The savings from the installations will provide an income stream over the life of the project.

Borrego Solar designed a portfolio of solar projects for the NMUSD comprised primarily of elevated shade structures that maximize the unused space on school properties throughout the district. The tight schedule and multitude of sites presented many challenges. The slim margin for error required seamless coordination of every step in the process, from meeting interconnection standards and design approvals for Southern California Edison (SCE) to managing permit applications and coordination with the California’s Division of the State Architect (DSA), which provides design and construction oversight for K–12 schools, community colleges and various other state-owned and -leased facilities. Additionally, the multiple parties in the project—including an Inspector of Record, the DSA, construction management firms, subcontractors, the district and SCE—needed to remain updated and involved throughout development and deployment.

At the core of Borrego Solar’s successful completion of the project was keeping things moving forward and on schedule. The team diligently stayed up to date with any changes that SCE made to interconnection requirements, and brought on an engineer to focus on working with the DSA and navigating the process to avoid any snags. The Borrego Solar project manager’s priority was communicating necessary information to the district and its hired construction management firm to avert any unexpected issues that could stall progress.

“While this was the greatest number of sites we have completed consecutively for one district, Borrego Solar has extensive experience working with the DSA and SCE, which proved essential in completing the NMUSD project on schedule. Our experience enabled the team to anticipate elements of the design where utilities occasionally push back. Because of Borrego Solar’s tight teamwork, it was possible to coordinate and complete many tasks across the portfolio, such as shutting off power and interconnecting 24 systems in a single day.”

Karla Martinez, Borrego Solar

Overview

DESIGN: Ben Walter, director of engineering for Western US, Borrego Solar, borregosolar.com

PROJECT MANAGEMENT: Karla Martinez, project manager, Borrego Solar

DATE COMMISSIONED: Project completed February 2016

INSTALLATION TIME FRAME: 32 sites total, installation time ranged from 44 to 87 days per site, depending on system capacity and site variables

LOCATION: Newport Beach and Costa Mesa, CA, 33.6°N

SOLAR RESOURCE: 5.5 kWh/m2/day

ASHRAE DESIGN TEMPS: 87.8°F 2% average high, 35.6°F extreme minimum

ARRAY CAPACITY: 3,222 kWdc project total, 32 sites total ranging from 23.52 kWdc to 540.96 kWdc

ANNUAL AC PRODUCTION: 5,182 MWh

Equipment Specifications

MODULES: 11,508 LG Electronics LG280S1C-B3, 280 W STC, +3/-0%, 8.78 Imp, 31.9 Vmp, 9.33 Isc, 38.8 Voc

INVERTERS: 3-phase, 277/480 Vac services, 42 Yaskawa–Solectria Solar PVI 14TL (14 kW rated output, 600 Vdc maximum input, 180 Vdc–580 Vdc operating range, 300 Vdc–540 Vdc rated MPPT range), four SMA Sunny Tripower 12000TL-US (12 kW rated output, 1,000 Vdc maximum input, 150 Vdc–1,000 Vdc operating range, 300 Vdc–800 Vdc rated MPPT range), 20 SMA Sunny Tripower 15000TL-US (15 kW rated output, 1,000 Vdc maximum input, 150 Vdc–1,000 Vdc operating range, 300 Vdc–800 Vdc rated MPPT range), 12 SMA Sunny Tripower 20000TL-US (20 kW rated output, 1,000 Vdc maximum input, 150 Vdc–1,000 Vdc operating range, 380 Vdc–800 Vdc rated MPPT range), 57 SMA Sunny Tripower 24000TL-US (24 kW rated output, 1,000 Vdc maximum input, 150 Vdc–1,000 Vdc operating range, 450 Vdc–800 Vdc rated MPPT range)

ARRAY: Source circuit parameters and array configurations vary based on array capacity, inverter model and number of inverters deployed per site

ARRAY INSTALLATION: Ground-mounted carports, Borrego Solar DSA Pre-Check design manufactured and installed by Resolute Performance Contracting, electrical installation by HMT Electric

SYSTEM MONITORING: AlsoEnergy portfolio monitoring

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