Bernalillo County

Project Details

The ground mount PV system consists of a 1.87720 MWp (DC) solar array which generates direct current (DC) from sunlight and supplies it to two (2) Centralized Inverters that convert DC electricity to 3-phase, alternating current (AC) electricity. The AC voltage from each inverter is stepped-up using a medium-voltage, oil filled transformer to 12.47kV – matching the facility’s primary distribution voltage configuration at the point of interconnection. The power and energy output of each Inverter shall be metered at 12.47kV, close to the point of system interconnection, on the facility’s existing primary distribution system, to ensure that any PV system wire losses have been taken into account prior to metering. Between the two (2) meters and their respective points of common coupling on the facility’s distribution system, medium voltage metal enclosed switchgear shall be provided, in-line, serving as a means of safe disconnect for the system, by the utility company and facility operators. Disconnect means shall be provided with external viewing windows to ensure safe disconnect operations and shall be externally lockable by the utility company in the open-position.

The PV array itself consists of (5,776) Hyundai 325Wp, utility-grade, monocrystalline, 72-cell PV modules. The PV modules are mounted on a single-axis tracker that follows the sun from morning (-52 deg) to evening (+52 deg) utilizing a GPS-based controller. The tracker boosts energy capture from the sun and therefore electricity generation by the PV system from sunlight to sunrise. The tracking system, model DuraTrack HZ-V3, is made by the Albuquerque-based company, Array Technologies Inc., and has become the standard for utility-scale projects in the US, with most MW’s installed. Each tracker row section holds up to 80 PV modules and is supported typically by 11 “W”-type steel columns.

The PV modules are electrically interconnected into strings of 19 modules, totaling 304 strings. Module strings are combined using fused string combiners that provide NEC-compliant over-current protection and segmented disconnecting means of the array allowing maintenance of portions of the array without having to shut down the complete PV system. Outputs of individual string combiners merge at the fused sub-combiner integrated into integrated fused re-combiners of their respective utility-grade inverters. The inverters also have integrated, load- break rated DC and AC disconnects for additional safety and isolation for maintenance.