North Colt Drive 9.4kW Grid Tied Solar System in Northern Arizona

North Colt Drive Grid Tied Micro-Inverter System


The array for the North Colt Drive System, showing the structure that houses the system.

The North Colt Drive system is a Grid Tied System that utilizes 33 Enphase S280-60, micro-inverters. This system will produce 16,135kWh over the course of a year. The monthly kilowatt hour production is plotted in the graph at the bottom.
There are trees to the south and southeast of the system, which could cause shading issues. The Micro-Inverters make it so that, if one panel is shaded, only the power from that panel is lost. The power from any other panel is not affected.

The North Colt Drive System includes 33 panels (33 Micro-Inverters) in 3, 20 amp circuits.

A 20A circuit of the S280 micro-inverters can contain a maximum of 14 units. This system employs 3 circuits of 11 inverters. The panels are split between a South facing roof, and a Southwest facing roof. The connecting trunk cables and home runs, back to the combiner, are run through the attic space.

The North Colt Drive Micro-Inverters circuit combiner (top left), Monitoring hardware (same enclosure), disconnect and meter (center) and service panel (left).

The 3 circuits are combined in the Envoy-S Combiner (top left above). The Envoy monitors each inverter connected in the system, and conveys the status and production information to the manufacturer’s servers. This information is available to the consumer, installer, and manufacturer. If an inverter in the system fails, the manufacturer is alerted, via the Envoy, and sends a replacement to the installer. Access to the Envoy output allows the installer to know which unit is faulty, and the installer goes to the site and replaces the faulty unit. This communication system streamlines the warranty replacement process, and provides everyone involved with up to date monitoring.

At the location of the North Colt Drive system, accounting for equipment inefficiencies, wire loss, typical environmental conditions, and the available solar resource, the kWh production of the the system is plotted, for each month.

A Grid Tied system, like this, currently costs approximately $27,000.00. After the 30% Federal Tax Credit, and the $1,000.00 State Tax Credit, the initial cost of the system is a little under $18,000.00. If the electricity rates continue in their current trend, this system will pay for itself in less than 7 years.