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PV System Basics

Solar photovoltaic (PV) panels convert solar radiation (termed “insolation”) into electricity for use in homes and businesses. PV systems typically contain several panels wired together in an array. The array produces direct current (DC) electricity, which is converted to alternating current (AC) electricity by an inverter. Other equipment associated with a solar PV array includes an electrical disconnect, overcurrent protection (circuit breakers or fuses), and a junction box. Grid-tied systems will also include a net meter, while off-grid arrays will have battery backup.

PV systems can be mounted on a rooftop, on the ground, or on a pole. Rooftop systems are the least expensive to install but are subject to the pitch and orientation of the roof. Ground mounted systems can generally be oriented south to maximize electricity generation. Community solar gardens tend to use ground mounted arrays, but may also utilize rooftops or pole mounts. Pole mounted systems allow for solar tracking, which can generate more electricity than stationary systems but at an additional cost and possibly with additional maintenance. In any system configuration, shade should be avoided between 9am- 3pm.

Knowing Your Solar Resource

The amount of solar electricity an array can generate is a function of the equipment and mount type as well as the amount of solar insolation reaching your panels. Insolation can be used to determine “peak sun hours”, which is the number of hours that solar insolation equals 1,000 watts per square meter. Peak sun hours vary throughout the year and can be affected by the Earth’s position relative to the sun, location of site (latitude), atmospheric conditions, and any obstructions at a given site (shade). In general, Colorado averages about 5.5 peak sun hours per day, with parts of the San Luis Valley experiencing 6 or more peak sun hours per day. Knowing peak sun hours can help you and your installer size a solar PV array for your home or business.

Is Solar PV Right For You?

Generating solar electricity allows you to avoid the costs of electricity supplied by the grid or can allow you to be independent of the grid. Using solar instead of grid-supplied electricity can also reduce your environmental footprint. There are many ways to participate in solar PV for your home or business. Systems can be purchased with cash, traditional bank loans, or “solar loans” through solar companies. Some solar providers allow for a solar lease option. Community solar gardens are available in some utility service territories. There are advantages and disadvantages to each type of arrangement, and your options should be considered carefully before making a decision. Financial incentives may be available for solar PV.

Last updated: February 15, 2018 at 12:59 pm