5.4 kw Solar Electric System in Ithaca, NY
Challenge
This 5,400 W (5.4 kW) grid-connected solar electric (PV, photovoltaic) system is installed as a roof-mounted array of twenty-four (24) SunPower 225W solar modules oriented South on the upper house roof.
Solution
This 5,400 W (5.4 kW) grid-connected solar electric (PV, photovoltaic) system is installed as a roof-mounted array of twenty-four (24) SunPower 225W solar modules oriented South on the upper house roof. The array is well-integrated with the house and aesthetically pleasing, and is arranged as three (3) rows of modules in landscape and one (1) smaller row of modules in portrait. The modules are mounted flush to the roof surface at a tilt of 20.5° using a UniRac Sunframe mounting system and low-profile Thompson Technologies Flat Jack standoffs with flashings to increase air circulation and ensure a water tight connection to the roof. The system is configured electrically as three (3) DC circuits (strings) of eight (8) series connected modules providing input to one (1) SMA 5000m, 5.0kW inverter. This inverter provides grid-synchronous AC output and interfaces to the electric utility through a dedicated circuit breaker in the Customer's main service panel, as existing infrastructure allows. System power production (kW) and cumulative energy (kWh) monitoring is provided by a SunPower Web-Based Monitoring System, as well as by a digital display on the inverter and an electromechanical meter. As designed, this system should generate an average of 15.2 kWh/day = 5,546 kWh/year, where daily energy production is both weather and seasonally dependent. This energy production is equivalent to 31% of the customer's present home electrical usage, and corresponds to a CO2 (greenhouse gas) emissions savings of 8,319 lbs per year.
