Solar Frontier Americas Development: Morelos del Sol

The 18.7 MWdc/15 MWac Morelos del Sol solar plant is located in Kern County, California. Solar Frontier Americas Development coordinated the project’s timeline and led an experienced team including EPC firm DEPCOM Power and engineering services provider Sisener Engineering. Solar Frontier’s advanced thin-film CIS modules, Clavijo single-axis trackers and Bonfiglioli power stations and inverters comprise the system’s major components. DEPCOM Power began construction on Morelos in May 2015. The plant reached commercial operation on November 25, 2015.

Project planning for Morelos del Sol began in 2010. The site’s geological features required detailed attention in the engineering phase. Site-specific challenges included a gas line that runs diagonally under the array field. The Solar Frontier Americas Development team worked closely with Southwestern Gas through preconstruction and build phases to execute in accordance with protocol and ensure safety. In addition, the development team coordinated with PG&E to time the interconnection to the site’s 34.5 kV–to–70 kV substation, accommodating back-feed restrictions and ensuring that no service disruption for other line users would occur.

The team specified Clavijo single-axis trackers for the project. With over 1 GW of fixed-tilt arrays and trackers installed worldwide and a pipeline of the same size for 2016, Clavijo is experiencing rapid growth in the US market. It has installed close to 100 MW of tracking systems in the US to date, primarily in California. Clavijo engineered a reinforced SP1000 tracker to accommodate the Solar Frontier CIS modules configured in two-up portrait orientation. This configuration maximizes the output of each power block.

Six enclosed Bonfiglioli 2.5 MW RPS Stations provide an added level of protection and security for the project’s 12 Bonfiglioli 1,350 kVA RPS TL-US central inverters (two per power station). The design called for prebuilt power stations to reduce on-site time and labor costs. The inverters feature six MPP trackers per unit, active power control, reactive power control, dynamic grid support and a CEC efficiency of 98.2%. Each power station has two ac circuits aggregated in a sectionalizer that will automatically isolate sections of the distribution system in the event of faults. The project design utilizes Cooper Sector Series 4-way sectionalizing switchgear.

Morelos del Sol will provide PG&E with a projected 40,215 MWh of solar energy annually under a 20-year power purchase agreement. In October 2015, Turner Renewable Energy and Southern Power, a subsidiary of Southern Company, acquired Morelos del Sol, expanding the utility giant’s renewable energy portfolio to eight solar projects in California with a total capacity of over 300 MW.

“Solar Frontier Americas Development is very proud of this project. Through close collaboration with our development team, equipment suppliers and construction partners, we completed Morelos del Sol on time, and it has met our quality and performance standards.”

Robb Owen, director of construction and engineering, Solar Frontier Americas Development


DEVELOPER: Solar Frontier Americas Development,


ENGINEERING SERVICES: Sisener Engineering, N.A.,

DATE COMMISSIONED: October–November 2015

INSTALLATION TIME FRAME: 162 days (mobilization to mechanical completion)

LOCATION: Lost Hills, CA, 35°N

SOLAR RESOURCE: 5.7 kWh/m2/day

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



Equipment Specifications

MODULES: 111,744 Solar Frontier CIS thin-film SF165-S and SF170-S, 165 W STC and 170 W STC, +5/-0 W, 1.95 Imp, 87.5 Vmp, 2.2 Isc, 112 Voc (SF170-S)

INVERTERS: Six Bonfiglioli 2.5 MW RPS Stations; 12 Bonfiglioli RPS TL-US 1350 central inverters (two per power station), 1,350 kVA rated output, 1,000 Vdc maximum input, six MPP trackers per inverter unit, 610–850 Vdc MPPT range, 406 Vac output; one medium-voltage 406 Vac Wye-to-35 kV Delta step-up transformer per RPS Station

ARRAY: Eight modules per source circuit (1,360 W, 1.95 Imp, 700 Vmp, 2.2 Isc, 896 Voc for SF170-S), 10–16 circuits per source-circuit combiner, 24 source-circuit combiners per RPS Station (typical); 18.72 MWdc plant total

ARRAY INSTALLATION: Tracked array, Clavijo single-axis trackers, 0° azimuth, ±50° tracking range of motion


SYSTEM MONITORING: DC Systems Real-Time Smart Energy Suite

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