System Overview
Type: Off-grid, battery-based, PV-wind system
Location: North Slope of Alaska
Solar resource: 4 average daily peak sun-hours (March–August)
Wind resource: 6 mph (2.7 m/s) average
Photovoltaics
Modules: Four Evergreen EC-110, 110 W STC,
16.4 Vmp, modules configured for 12 VDC nominal
Array: One four-module series string, 440 W STC,
65.6 Vmp, 48 VDC nominal
Array installation: Stationary mount oriented toward true south, 70-degree tilt angle
Wind Turbine & Tower
Turbine: Proven WT600
Rotor diameter: 2.6 meters (8.4 feet)
Rated energy output: 124 KWH per month at
12 mph (5.4 m/s)
Rated output: 600 watts at 25 mph (11 m/s)
Tower: 20-foot (6 m), custom-built tilt-up
Energy Storage
Batteries: 24 Deka Unigy II, 2 VDC industrial cells,
360 AH per cell at 20-hour rate, AGM
Battery bank: Two 12-cell series strings, 24 VDC nominal, 720 AH total
Balance of System
PV charge controller: OutBack MX60, 60 A, MPPT,
48 VDC nominal input, 24 VDC nominal output
Wind turbine charge controller: Proven diversion controller with air heater, 24 VAC nominal wild
3-phase input, 24 VDC nominal output
Inverters: Two OutBack FX2024, wired for single unit operation (redundant) with relay actuated backup, 2,000 W each, 24 VDC nominal input, 120 VAC output. Transformer is used to step-up 120 VAC output to 240 VAC for transmission to instrument site.
System performance metering: NPS proprietary “Remote View” for original module. SRI developed data acquisition system (DAQ) for monitoring RE components. Near real-time status display via the Internet.
