Grid Tie Vs Off Grid Solar Powered Systems
Can the sun provide enough power to run a business or house hold? The answer is absolutely but it depends on the solar powered system and its application. There are three basic types of solar powered systems available today, Grid-tie, Grid-tie with battery back up and Off-grid. Deregulation and net metering laws make a grid-tie system attractive. If there is no utility at all then the choice would be clear, off-grid. If you want back up power in case of a power failure then a grid-tie system with battery back up would be the logical choice. For a little more  explanation of the similarities and differences between all three systems, please read on.
Grid-tie, also called grid interactive or utility interconnected, it connects directly to the utility feed. This works only in areas of the country that allow net metering. Solar power turns the electric meter backward when producing more power than used. A grid-tie system consists of solar panels, a grid-tie inverter, fuses and a power cut off switch. This type of solar system is wired directly to the utility feed through the main breaker panels and utility meter. When more power is generated than used it is sold back to the utility company. This is the least expensive system to purchase and to maintain but provides no back up power in case of power failure.
Grid-tie with battery backup, this type of solar system is roughly the same as the grid tie system with a couple of additions. Along with the inverter and solar panels you would need 12 volt batteries, a battery charger and a solar charge controller. With the addition of the batteries comes a little more maintenance. A solar charge controller is used so overcharging or undercharging the batteries will not occur. A battery charger is used to charge the batteries when there is utility power available. Although this system is more expensive than the plain grid-tie system it does provide power when there is a utility power failure.
Off-grid system, this type of system is totally independent of the utility grid. It is most commonly use in areas where electricity is not available. It is basically the same configuration as the grid tie with battery back up but a different type of inverter is used. Â In an off-grid system you would not use a grid-tie inverter but an off-grid inverter. I guess that makes sense. Some inverters can be used either way but others have very specific applications. A little homework is necessary to be sure all of the individual components are compatible. This type of solar powered system is used many times with a generator for backup when the system does not meet all of the wattage requirements.
With more and more mass produced solar products on the market today the prices are coming down. There are energy credits, federal incentives as well as state and local incentives that make obtaining a solar powered system much more affordable. For more comprehensive information go to a website called, www.dsireusa.com. It will tell you what incentives are available in your area. The site will also indicate if net metering is available to you. A little homework is needed before deciding exactly which type of solar powered system is right for your needs.
Bob Gambrell has been in the past a manufacturers representative for Inverters, Battery chargers and wire. He currently owns and operates
Unique Solar Products. For more information on Solar Powered Systems or Solar Panels go to www.UniqueSolarProducts.com