Solar Battery Backup Systems: Get the Most for Your Money

Solar battery backup systems store leftover energy from your photovoltaic panel arrays, and that saves you money.

Rather than feeding that extra electricity back to the grid or wasting it, this high-tech equipment saves it for later. With a battery bank, you can use solar power even when the sun isn’t shining.

Although you don’t have to include a backup system with your solar installation, you may want to.

Solar Battery Backup Technology

FLA batteries (deep-cycle flooded lead acid) are the most common type used in photovoltaics, and they have a proven history of solid performance.

These batteries also work well when they’re partially charged, and they typically have a long life. FLAs do require some periodic attention, however, as the liquid electrolyte inside evaporates over time, so their water levels must be maintained.

For a lower-maintenance solar battery bank system, VRLA batteries (deep-cycle valve-regulated lead acid) are an option.

VRLAs internally convert oxygen and hydrogen into water, eliminating the need to maintain liquid levels. In addition, because they contain no free acid, these batteries can be installed in any position, unlike flooded acid models.

VRLAs carry a higher voltage level and dispense a charge at a higher rate than FLAs; however, they also have fewer life cycles and generally cost a bit more than FLA units.

Factors That Affect Solar Battery Costs

Although the initial purchase and installation cost is certainly a consideration, let’s evaluate the cost of ownership over the lifetime of your backup system.

Investing in an inexpensive backup system may sound good, but it also may lead to more frequent replacements. Capacity, or the amount of energy the batteries can store, is one factor that can affect the life of your deep-cycle batteries.

Battery cycle life, or the number of charges and discharges the battery can provide before capacity falls below 80 percent of the original level, also affects lifetime ownership costs.

Choosing a Solar Battery Backup System

Your battery bank obviously will increase your overall photovoltaic system costs, so choosing the right batteries can help maximize your return on investment.

The most important consideration is to purchase a battery bank that is sized properly and meets your system’s requirements for voltage. A large capacity may not be necessary if your array is tied to the grid. But if yours is an off-grid system, you will need a bank large enough to hold a few days’ worth of electricity.

Even if you have a grid-tied system, a larger backup system will be more cost-effective if your local utility does not offer net metering, or if their net metering terms are unfavorable.

At Intermountain Wind & Solar, we are dedicated to helping our customers reduce or eliminate their electric bills and establish true energy independence. If you are located in Utah, Colorado, Wyoming, Nevada or Idaho, contact us today to learn more.

If you plan to invest in your own PV panel array, be sure to ask how you can increase your system’s effectiveness with a solar battery backup system.