About This System

The readout shown on our home page is for a residential solar-electric system installed in 2006 near the California coast in San Diego.

The photovoltaic system consists of a total of 20 crystalline silicon modules with a nameplate peak capacity rating of 208 watts each. The inverter, which has an internal fan, is located in the garage.

The "nameplate" capacity of the system is about 4.2 kilowatts DC. It is obtained by multiplying the number of modules times the rated capacity of each module. The term refers to the maximum potential production, in watts, of the equipment at a particular point in time under perfect conditions.

Installed solar PV systems are typically "derated" by 20 to 25 percent to account for inevitable losses that occur in wiring, inverters, transformers and diodes, or are attributable to slight mismatches in module voltage characteristics, soiling, aging, shading and more. This derating allows for a more accurate estimate of a system's production over time.

The modules for this system are set 6 inches above the rooftop's Spanish-style tiles, allowing cool ocean breezes to help keep the system operating at high efficiency.

One section of six modules is offset to avoid a chimney's seasonal shadow. The panels are unshaded and are south-facing in line with the roof's 15-degree angle. At this angle, which is 17.5 degrees less than San Diego's latitude of 32.5 degrees, the system maximizes summertime production.

The residents report that they climb a ladder about once a month to hose off the panels and ensure a high level of production efficiency.

The system's owner wishes all to "Have a sustainable future!" Sunpluggers.com thanks the owner and Fat Spaniel Technologies for sharing the production data from this solar-electric system.