Solar panel systems are one of the fastest-growing energy sources in the U.S. Find out in our solar battery section everything you need to know about solar batteries.
What Are Solar Batteries? - An Overview
A solar battery is a battery that stores energy generated by a solar panel system. It is an additional component to a solar panel system that allows you to use energy later such as at night, or when your solar panel systems are no longer producing electricity.
How does a solar battery work?
First, a solar panel system converts solar energy into electricity which then passes through an inverter. The inverter converts the electricity from DC electricity (direct current electricity, which is when electrons flow in a single direction around the circuit) to AC electricity (alternating current electricity, which is when electrons flow in different directions). The solar battery takes the excess electricity that is not used right away and stores it for later use.
When it gets dark or when your solar panel system is not generating electricity, the system will draw upon the electricity stored in the solar battery. Typically, a solar panel system is connected to the electricity grid, and this is where excess electricity is stored. However, with a solar battery, excess energy will only be sent to the grid when the battery is fully charged and will only be drawn from the grid when the battery is depleted. With a solar battery, you can be energy independent and go off the grid.
Types of solar batteries
There are two common solar battery types:
When considering which type of battery to use, you should consider battery lifespan and warranty, power capacity, and depth of discharge (DoD). Battery lifespan can range from 5 to 15 years. This range is expected to increase as technology improves. Warranty is measured in either years or cycles. Power capacity is the amount of energy a battery can hold at one time. DoD measures how much energy you can use of the battery’s total power capacity.
Lithium-ion batteries are more compact than lead-acid batteries. They have a higher lifespan and higher DoD. However, they are less affordable than lead-acid batteries. Lead-acid batteries are less expensive but have a lower DoD compared to lithium-ion batteries. They have been used for decades but are now becoming outdated as a result of technological advancement.
Benefits of solar batteries
There are many benefits to having solar batteries installed in your home or business along with solar panel systems. One of these benefits includes maximizing the use of the electricity that you generate. Solar batteries can allow you to use 100% of the electricity you generate around the clock. A solar battery can also help you reduce your electricity bills. With a solar battery, you will not have to rely on the grid for electricity during the night or when your solar panel system is no longer generating electricity. You will also not have to pay the more expensive energy prices during peak hours since you can use the energy stored in the solar battery instead. This will lower the energy costs that you would have incurred relying on the grid. Another benefit of a solar battery is that it will allow you to become completely independent of the grid. This significantly decreases your carbon footprint and allows you to become fully energy independent.
Why Solar Batteries?
Benefits of Solar Batteries
Backup Energy Source
Solar batteries are charged when your PV (photovoltaic) panels are producing more energy than a building or home is using. This means that you will now have access to an energy source that does not rely on the power plants in your area. Thus, if a power outage were to occur in your area, solar batteries will continue to provide electricity. Solar batteries are a great idea if you want to live off the grid! With just a one-time cost for the battery, you can free yourself from high energy costs.
PV panels in combination with solar batteries provide a building or home with more independence from power plants in your area. Depending on what type of power plant your state utilizes, you may actually be lowering your carbon footprint! Some power plants rely on the burning of fossil fuels to produce electricity! This includes burning coal or natural gases. By lowering your reliance on it, you are lowering your carbon emissions and making the planet greener.
Time of Use Tariff
Some facilities may be affected by the Time of Use Tariff (TOU). TOU indicates that a facility’s price of electricity is different depending on when it is being used, indicating that the price can change depending on the time of day. TOUs have peak pricing, or high prices when electricity demand is high. If you have a solar battery, you can avoid this higher pricing by relying on your battery for energy during peak pricing.
Cons of Solar Batteries
Not Much Money May Be Saved
Depending on where you live, you may not save that much money. If your state or building is unaffected by TOUs, then installing a solar battery will not necessarily help you save money. Though you are still relying less on power plants, prices of electricity remain stagnant which leads to no money saved. It is best to reach out to us to seek help in calculating if an investment in a solar battery will yield a better return. Sign up with us here.
Sometimes, your household may not be the right fit for the installation of a solar battery. Solar batteries must be installed in a ventilated and cool environment to prevent the unit from getting too hot. Unfortunately, not all houses may have an area that fits these requirements for installation. Again, reach out to us to determine if a solar battery is right for your home.
How to Add a Solar Battery to a System?
The difficulty of adding a solar battery to an existing solar energy system is dependent on the design of the solar system. If your existing solar system is a storage-ready system, then installing batteries will be easy because the inverter can easily incorporate the battery. Having a storage-ready system is the easiest and cheapest way to add a battery to your system. However, if you do not have a storage-ready system, there are two other options you can use to add a battery: AC Coupled System and DC Coupled System.
AC Coupled System
With an AC Coupled System, your existing inverter will remain which won’t cost you anything. Your battery will be integrated into the solar system by using an additional second inverter. The existing inverter converts DC power produced by your solar panels into AC power and sends it to the grid if the battery is fully charged, or to your home when you are using electricity. Since solar batteries only store the DC form of power, the AC power also flows to the second inverter which converts the AC power back to DC power.
The AC Coupled System solution is a low-cost option because there is no need to remove your existing inverter, and it allows for more flexibility. However, this solution provides efficiency loss due to additional conversion processes from DC to AC that is not present with a single inverter.
DC Coupled System
In a DC Coupled System solution, your existing inverter will be replaced with an inverter that works to integrate a battery into your solar system. This inverter is known as a hybrid inverter. The DC power produced by your solar panels flows to the battery through the use of a charge controller where there is no conversion. From the battery, the DC power moves to the hybrid inverter which then converts DC power to AC power that can be used for home appliances or the grid.
The DC Coupled System solution is a more efficient option because it loses less energy in the conversion process as there are fewer steps. However, this solution is more costly compared to the AC Coupled System because you have to replace your current inverter which can be a complicated process. This option is suitable for someone whose inverter is reaching its life expectancy (10-15 years).
Need help with adding a battery to your system? By signing up with us, we will guide you through the process and match you with solar companies in your area that can help you.
Solar Battery Cost
When deciding whether or not to add a solar battery to your solar energy system, it is important to consider the costs. This is because adding a solar battery can increase installation costs significantly. These costs are dependent on the type of battery you choose, the number of batteries you need, and if your battery has its own inverter.
How much are solar batteries?
Types of batteries
There are two types of solar batteries: lithium-ion and lead-acid. When considering which type of battery to use, you should consider battery lifespan and warranty, power capacity, and depth of discharge (DoD). The battery lifespan can last between 5 to 15 years. Because lithium-ion batteries have a higher lifespan and DoD, they are more expensive than lead-acid batteries.
Number of batteries needed
The amount of batteries installed for your solar system is less flexible than adding or subtracting solar panels from your system. This is why the cost of adding batteries is high and will depend on how much energy you need to store.
Because the difficulty of adding a solar battery is dependent on the design of the solar system, you need to understand what type of inverter you already have. Your home uses AC power; however, batteries only store DC power. If you have an existing hybrid inverter, then the cost of adding a battery will be lower because hybrid inverters readily allow you to connect batteries to your solar system. If you do not, you will either need to replace your current inverter with a hybrid inverter or purchase an additional inverter that will convert the AC power back into DC to send to the battery. Replacing or adding an additional inverter will incur higher costs.
Tax Incentives/Incentives for Solar Storage
Similar to solar incentives for installing solar systems, there are a number of incentives for homeowners and business owners wanting to invest in battery storage.
Solar batteries and the Investment solar tax credit
The federal investment tax credit is a program that offers tax credits to home and business owners who invest in solar projects for their properties. In 2021, homeowners and business owners could deduct 26% of the total cost of their solar system from their income taxes. Solar energy storage also qualifies for the federal investment tax credit under the condition that the “storage systems owned by homeowners must derive all 100% of their power from an onsite solar array.” However, this is different for business owners. Business owners that invest in solar batteries are eligible for the tax credit “only if at least 75% of the charging storage unit is provided through solar generation.” This means that if the business owner’s battery was charged by your solar system 75% of the time, then it would be eligible for 75% of the current tax credit.
State level cash rebates and performance-based incentives
A number of states in the United States offer direct cash payments to homeowners who have installed and connected their solar battery to the grid. Some of these programs include California’s self-generation incentive program, which is designed to provide cash rebates for qualified energy storage systems and the Massachusettes’ renewable target (SMART) program, where any solar energy credits sent to the utility will be automatically compensated by that utility.
To find out more about your state-level incentive programs and what you are eligible for, sign up with us today!
Solar + Storage for Resiliency
A solar battery that stores energy generated by a solar panel system allows solar energy to be used at all times. This makes it possible to use energy during the night and at times when your solar panels are no longer producing electricity. A solar system coupled with battery storage provides significantly higher self-consumption and serves as a backup energy source when there is a power failure. Solar + Storage for Resiliency is an excellent strategy for disaster preparedness. The advantages of coupling solar with storage for emergency power include:
- Solar batteries don’t require a lot of maintenance whereas backup generators are consistent with monthly testing and costly maintenance.
- Solar batteries do not contribute to poor air quality as compared to backup generators powered by diesel or gas.
- Solar with storage provides long-term financial savings with lower energy bills.
At enlighten.energy, we can help you with your solar storage system. Sign up with us to learn more.