Solar Electric Overview

What are the Main Types of Solar Electric Systems?

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There are three main ways to configure a photovoltaic system. They are: Stand-alone; Hybrid; and Grid-tie systems.

The Stand-alone system uses an array of PV modules to supply your total electric needs. During the sunny days, excess energy is stored in a battery bank. That energy is then available for use at night or on cloudy days. PV systems are sized to keep you supplied even during the short days of winter or when it’s cloudy for few days in a row. The advantage of this system is that it is completely independent of traditional energy sources and a fully functional system can be installed almost anywhere.

Hybrid systems use other energy generation sources in conjunction with PV. They are a great option for areas that don’t have consistently sunny days. Wind generators are a good option in many areas. It is also possible to install a gasoline, diesel, or propane generator. A well-designed system configured in this way can supply all your power needs by running a generator just a few hours every day or two. This can save on wear, tear, fuel, and maintenance on your generator, as well as the annoyance of generator noise. The advantages of the Hybrid systems are their lower costs and their high margin of flexibility.

The third type of system is called "Grid-tie" or sometimes "Line-tie." In this system, the electricity your solar panels generate is fed directly into your local utility company lines. During the day, your system produces enough electricity to supply part or all of your electricity needs. Any excess power is sent back to the grid and either sold back to the utility company at cost, or your meter simply runs backward, lowering your electric bill. At night or when you need more power than you are producing, that power is supplied by your utility. One advantage of this type of system is that a battery bank is not required, which lowers costs. Many utility companies throughout the country offer incentives for Grid-tie systems. Check with your local electricity provider regarding the availability of programs. If you live in Tucson, Arizona and are in the Tucson Electric Power service area, click here to visit their Green Watts home page for more information.

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