Haleakala Solar: Clark Residence

One of the oldest solar installation companies in Hawaii, Haleakala Solar has been installing solar hot water and PV systems since 1977. Around 2010, the company experienced an increase in demand for PV systems for condominiums and apartment complexes under the stipulation that the installations met newly enforced homeowner’s association (HOA) and Association of Apartment Owners (AOAO) policies regarding array aesthetics and protection. This included a mandate for skirting around the solar array to conceal the module frames and racking system. Completed in December 2015, the Clark residence solar array complied with these new HOA guidelines.

The installation interconnects to the Maui Electric Company’s grid under the Net Energy Metering (NEM) program. The Clark residence was one of the last systems Haleakala Solar installed that enjoys the one-for-one credit earned when exporting energy into the grid. As of October 2015, the Hawaii Public Utilities Commission, in conjunction with the Hawaiian Electric Companies, discontinued the NEM program and implemented the Distributed Energy Resources program, which adversely affects the economics of solar in Hawaii.

Haleakala Solar chose Mounting Systems’ Alpha+ racking and Quick Mount PV’s Quick Hook system for securing the array on the home’s tile roof.  Compared to hanger bolts, the flashed tile hook system results in a lower-profile array with a more durable watertight seal. The use of tile hooks requires installers to put in more labor in the field, but the hooks save money in the long run by minimizing potential roof leaks the integrator may have to address.

When HOAs first started introducing new aesthetic guidelines, Haleakala Solar approached various vendors looking for a skirt solution that would conform to the new requirements. Unable to find a suitable product, the Haleakala Solar team opted to develop its own solution. While this company-made skirting met the requirements for approval, it was expensive to produce and time-consuming to install. Tony Racanelli, a representative for array barrier manufacturer SolaTrim, introduced one of Haleakala Solar’s key customers, the Wailea Community Association, to the SolaTrim product. Haleakala staff discovered that SolaTrim addressed all their needs for a robust, cost-effective skirt.

In addition to addressing aesthetic considerations, the SolaTrim product protects array wiring from pests and the buildup of vegetation debris.  While Haleakala Solar’s installers were initially concerned that the Hawaiian tropical winds would cause the SolaTrim panels to separate from the module frames, the manufacturer has tested its product design and military-grade adhesive system for just such applications and has designed it to last for the lifetime of rooftop PV systems.

Due to the large energy demands of the residence, the design uses almost all the available roof space for solar, including the north-facing surfaces. Because of the site’s close proximity to the equator and moderate roof slope, the north-facing modules produce at 80% capacity. Haleakala Solar selected Enphase inverters to mitigate the effects of periodic shading due to the surrounding vegetation and second-story roof.

“SolaTrim eliminated the costs associated with Haleakala Solar’s manufacturing of its own aesthetic skirting. SolaTrim’s adhesive-based product cuts skirting installation to just a few hours on systems such as the Clark residence. In addition, the barrier satisfied the HOA’s skirting requirements.”

—Jasen Hartford, commercial energy consultant, Haleakala Solar

Overview

LEAD DESIGNER: Ryan Delpier, residential design manager, Haleakala Solar, haleakalasolar.com

LEAD INSTALLER: Terrence Fuentes, installation lead, Haleakala Solar

DATE COMMISSIONED: December 2015

INSTALLATION TIME FRAME: 5 days

LOCATION: Wailea, Hawaii, 20.7°N

SOLAR RESOURCE: 5.46 kWh/m2/day

ASHRAE DESIGN TEMPERATURES: 87.8°F 2% average high, 55.4°F extreme minimum

ARRAY CAPACITY: 21 kWdc

ANNUAL AC PRODUCTION: 36.43 MWh

Equipment Specifications

MODULES: 70 LG Electronics LG300N1K-G4, 300 W STC, +3/-0%, 9.26 Imp, 32.5 Vmp, 9.7 Isc, 39.7 Voc

INVERTERS: Single-phase 120/240 Vac service, 70 Enphase M250-60-2LL-S22, 250 W peak output, 240 W rated (continuous) output, 48 Vdc maximum input, 27–39 Vdc MPPT range, 16–48 Vdc operating range

ARRAY: Four 16-module ac source circuits (4 kWac peak, 16 kWac total), one six-module ac source circuit (1.5 kWac peak); array total 17.5 kWac peak

ARRAY INSTALLATION: Roof-mount Monier concrete tile, Mounting Systems Alpha+ racking, Quick Mount PV Quick Hook mounts, SolaTrim array barrier, multiple roof azimuths (32 modules at 107°, 12 at 197°, 22 at 287° and four at 7°); 18° tilt (all arrays)

AC CIRCUIT AGGREGATION: One Eaton BR816L125RP 125 A outdoor load center, 20 A Eaton BR220 breaker per ac source circuit; 15 A Eaton BR115 breaker installed in PV load center feeds a receptacle that powers the Enphase Envoy communications gateway

SYSTEM MONITORING: Enphase Envoy communications gateway, Enphase Enlighten web-based monitoring

Article Discussion