Nova West Solar: Beam Residence

Fresno, California–based Nova West Solar designed, planned and installed a 10.7 kWdc ground-mount PV system at the Beam residence in Clovis, California. A 5-acre grove of actively farmed navel oranges surrounds the home. In 2008, the Beams had a PV system installed on the roof of their residence. The original system did not offset the customer’s home and business electricity usage, which prompted the Beams to contact Nova West Solar to install an additional array. Combined, the solar arrays offset 100% of the Beam’s annual electrical load. The new PV system will save more than $221,000 over the system’s life cycle and has a 4.5-year simple payback on the family’s investment.

The project presented several obstacles, and allowing for future expansion of the system created additional design requirements. Recent fire codes mandate 3-foot setbacks on rooftop PV arrays, necessitating ground mounting of the new array. The existing electrical panel also presented a hurdle. Nova West Solar landed the single-phase 240 Vac output of the SolarEdge 11.4 kW inverter at a new 60 A breaker in an existing 200 A subpanel. To keep the maximum available current below 120% of the panel’s bus rating, the installer replaced its 200 A main breaker with a 175 A main breaker.

Nova West Solar’s design for the system couples 33 high-efficiency 96-cell Panasonic HIT modules with an 11.4 kW SolarEdge string inverter. A SolarEdge P400 dc optimizer (33 total) monitors and optimizes the output of each individual module. Together, the modules and the power conversion platform maximize energy production and minimize the array’s physical footprint. The result is a system that reduces the area required for the array by approximately 20% compared to an installation using standard modules and power electronics. For the Beams, this meant they needed to remove fewer citrus trees to make space for the PV array. SolarEdge’s module-level optimizer system minimizes the impact of module soiling and shading from the adjacent orange trees and allows for the easy addition of modules down the line, should the family require additional power to run their home and business.

“The combination of Panasonic HIT modules and SolarEdge’s dc optimizers and inverter is a match made in heaven. Panasonic’s high-efficiency module design maximizes energy production, and the modules have an incredibly low failure rate. The costs associated with diagnosing module failures and subsequent replacement and warranty claims can add up quickly and tie up valuable person hours and other resources needed to handle callbacks. High-quality modules and module-level monitoring minimize long-term financial exposure.”

TJ Shelton, Nova West Solar

Overview

DESIGNER: TJ Shelton, operations manager, Nova West Solar, novawestsolar.com

LEAD INSTALLER: Frank Ramirez, installation lead, Nova West Solar

DATE COMMISSIONED: June 29, 2016

INSTALLATION TIME FRAME: 5 days

LOCATION: Clovis, CA

SOLAR RESOURCE: 5.7 kWh/m2/day

ASHRAE DESIGN TEMPERATURES: 102.2°F 2% average high, 28.4°F extreme minimum

ARRAY CAPACITY: 10.7 kWdc

ANNUAL AC PRODUCTION: 17.36 MWh

Equipment Specifications

MODULES: 33 Panasonic VBHN325SA16, 325 W STC, +10/-0% 5.65 Imp, 57.6 Vmp, 6.03 Isc, 69.6 Voc, 96 cell

INVERTERS: Single-phase 120/240 Vac service, one SolarEdge SE11400A-US, 11.4 kW, 500 Vdc maximum input voltage, 350 Vdc nominal input voltage at 240 Vac; 33 SolarEdge P400 Power Optimizers, 400 W rated input, 8 Vdc–80 Vdc MPPT range, 80 Vdc maximum input

ARRAY: 11 modules per source circuit (3,575 W), three source circuits, 10.725 kWdc array total at 350 Vdc nominal (module-level current controlled by power optimizers)

ARRAY INSTALLATION: Ground-mount IronRidge XR1000 rails, 2.5-inch schedule 40 galvanized pipe substructure, 180° azimuth, 19° tilt

SYSTEM MONITORING: SolarEdge module-level monitoring

Article Discussion