TriAxis Engineering provided initial development planning, medium-voltage interconnection design, generation step-up transformer specification and review, on-site construction inspection, specification and programming of medium-voltage padmount recloser, coordination of protective systems and schemes with local utility.
Completion Date: 2013
SOLARCITY 14.175MW, 12MW AC PHOTOVOLTAIC POWER PLANT Island of Kauai, Hawaii
14.175MW DC, 12MW AC, photovoltaic power plant built by SolarCity near Koloa on the southern side of the Island of Kauai. The plant includes 24 500kW inverters feeding 8 1500kVA 12.47kV-420V transformers. The 12.47kV medium-voltage collection system and interconnection to Kauai Island Utility Cooperative was designed by TriAxis Engineering. Low-voltage DC design and low-voltage from the inverters to the step-up transformers was developed by SolarCity with design supervision by TriAxis Engineering. TriAxis Engineering acted as the Engineer of Record.
RABBIT RESEARCH LAB PHOTOVOLTAIC SYSTEM Corvallis, Oregon Owner: Oregon University System
TriAxis Engineering provided interconnection support, low-voltage and medium-voltage design, and was the electrical engineer of record for this 1.5MW electric photovoltaic project developed by SolarCity of California and built on the Oregon State University campus in Corvallis, Oregon. The work included underground 600VAC and 20.8-kV design, transformer specification, protection design, and interface with the local utility (PacifiCorp) through the System Impact Study and Facilities Study interconnection process.
The plant includes over 5700 250Wdc photovoltaic modules on fixed supports, DC-system combiners and recombiners, 500-kW Xantrex inverters, 208V-20.8Y/12.0-kV 500-kVA padmount transformers, 25-kV underground cabling, a 25-kV Siemens padmount recloser to provide interconnection isolation from the utility system, and a 25-kV class padmount primary meter per utility standards. The interconnection protection scheme includes fiber-optic based transfer trip to the utility substation.
Commissioning is expected in November 2013. Completion Date: 2013 Design work for which TriAxis was responsible: 100%