Adding Batteries to Your Solar and Battery System

Adding batteries to your solar system provides energy independence and backup power. They also allow for time-of-use optimization and load shifting to avoid expensive utility rates during peak demand times.

Without a battery, your solar system will send unused electricity back to the grid and you’ll pay the same rates as everyone else. With a battery, however, this excess is captured and stored for use at night.

Solar Panels

Solar panels, also called photovoltaics, convert sunlight into electricity for homes and businesses. A solar panel is made up of multiple silicon photovoltaic cells, which can be arranged in a variety of shapes and sizes to suit the needs of the customer. Solar cells convert solar energy into electrical energy by creating an imbalance of electrons between the front and back surfaces of the cell. This creates a voltage potential similar to the negative and positive terminals of a battery. Electricity flows through conductors on the front surface of the cell, providing energy to household appliances and equipment.

Most homeowners will find that their solar system pays for itself in reduced electricity bills over a lifespan of 20 to 30 years. In addition, solar systems are carbon-free and can help reduce greenhouse gas emissions.

A solar battery can provide backup power for your home or business during times when the sun is down or behind clouds. Batteries are also used to offset high electricity prices during peak demand.

There are several important considerations when choosing a battery, including its capacity and voltage. The capacity tells you how much energy the battery can hold at one time, and the voltage identifies its maximum current capability. It is also necessary to consider the charge rate, which refers to how quickly a battery will be refilled when connected to a charger.

Batteries

A solar battery stores excess energy from your PV system for use at night or during a power outage. It’s a reservoir of power that can also decrease your reliance on the utility grid. The type of battery Solar and Battery System you choose depends on how much you want to back up your home and how much electricity you consume.

Solar batteries are typically lithium ion, and they come in multiple sizes. There are also different lithium chemistries, such as nickel-manganese-cobalt, lithium polymer and lithium iron phosphate. These batteries are safer than older lead acid models, and they have a higher round-trip efficiency—meaning that more energy gets used than is lost to heat.

The battery can also be programmed to discharge during time-of-use rates, which will lower your electricity bill. However, you’ll need to understand your state and utility solar billing policies before seeing any additional savings.

The cost of a solar battery can vary dramatically depending on the size, brand and other factors that are specific to your system. Generally speaking, local installers will be best equipped to help you evaluate your options and decide what kind of battery will fit your needs. They can also give you quotes for the battery itself and installation. They may also charge upcharges that you’ll need to factor into your overall budget, such as the inverter that converts DC from the solar panels and the battery into AC for the electric grid or home.

Grid-Tie

A grid-tied solar system is connected to the utility grid and is able to give and sell energy. The most common reason to install a solar battery company solar grid-tied system is to offset energy consumption and reduce electric bill totals. A copy of a recent electric bill is one of the best tools for determining site energy consumption and will help in sizing a system. Offsetting 100% of a site’s electricity usage is ideal, but even offsetting 75% will have a significant impact on a household or business’s bill.

These systems use a solar panel array and a grid-tie inverter to first satisfy energy needs before feeding the surplus power back to the utility grid. If net metering is available from your local utility, you will receive credit on your bill for this excess power. A traditional solar grid-tied system uses string inverters, which are sized by the number of panels connected in a “string”. The output wattage of a string inverter directly correlates to its input wattage from the panel strings.

Another great benefit of a grid-tied solar system is the ability to generate something called SREC’s (Solar Renewable Energy Credits) for each kilowatt-hour of power that is produced. These credits are sold on the SREC marketplace in Pennsylvania and can significantly increase your return on investment. Use our free online calculator to get an idea of how much a solar system will cost you based on your monthly energy bills and whether or not you would like to include battery backup.

Off-Grid

An off-grid system is powered exclusively by your solar panels and battery storage, allowing you to be completely independent of electricity retailers. This is the ultimate goal for many homeowners, and requires a robust system that can produce enough energy at night or during long stretches of inclement weather to meet your needs. While it offers greater independence from rising electricity prices, it is also a significant investment and not suited to every home.

Like grid-tied systems, off-grid solar power systems use standard solar equipment—solar panels, racking, and wiring. Batteries are used to store the energy produced by your solar panels, and an inverter converts the DC voltage of the batteries to alternating current that is used for most household appliances. An inverter sized to accommodate the peak electricity load of your home is recommended, and it is best if it uses maximum power point tracking technology rather than pulse width modulation.

An off-grid battery system is most effective when paired with a home energy management system (HEMS) that takes into account electricity prices, forecasting, and the real-time load at your site to optimize your energy usage and minimize costs. Some utilities offer compensation for the excess electricity that is sent to the grid, known as net metering or other methods of crediting your account. In these situations, a battery can be used to store excess electricity during low price periods and then draw on that stored power during peak demand to avoid paying higher utility rates.