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CLEAN ENERGY REVIEWS. Solar and battery installation

CLEAN ENERGY REVIEWS. Solar and battery installation

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    Reviews and information on the best Solar panels, inverters and batteries from SMA, Fronius, SunPower, SolaX, Q Cells, Trina, Jinko, Selectronic, Tesla Powerwall, ABB. Plus hybrid inverters, battery sizing, Lithium-ion and lead-acid batteries, off-grid and on-grid power systems.

    September 6, 2022 Jason Svarc

    The huge leap forward in battery technology has seen an immense amount of interest in people looking to go off-grid, store their excess solar energy to increase self-consumption, and become energy independent. However, the Rapid pace of technology has resulted in some confusion over what is achievable and which battery system is best suited to individual households. Costs can also vary widely depending on the amount of energy storage capacity (measured in kWh) and the type of solar inverter required.

    New to solar and batteries? See our basic introduction to battery systems and the different types of solar systems, including grid-tie, off-grid and hybrid.

    How much does a Home battery system cost?

    The cost of home battery systems depends on the battery size or capacity, measured in kilowatt-hours (kWh) and the brand of solar or hybrid inverter used. Average household batteries cost anywhere from 4000 for a small 4kWh battery up to 15,000 or more for a sizeable 12kWh battery, depending on the type of battery, installation location, backup power requirements and type of inverter used. Costs have slowly been reducing but not as quickly as many had hoped.

    To give some perspective, an average 3-bedroom home uses around 20kWh of electricity per day. However, some of this energy is used during the day and could be directly powered by solar alone. With this in mind, a moderately sized 10kWh battery would generally be large enough to cover the evening and overnight periods. In reality, every household is different, and usage patterns can vary greatly. For those that are more energy conscious and use efficient appliances, a smaller 5 to 6kWh battery may be suitable and also provide enough backup power to support basic essential loads such as lighting, computers and fridges.

    Basic battery cost guide

    As a general guide, in Australia, a battery system will cost around 1000 per kWh installed, or in the US it’s closer to US700 per kWh. For example, the Tesla Powerwall 2 with 13.5kWh of storage capacity will cost around US 15,000 fully installed, while the 9.8kWh LG RESU battery costs around US 6000 plus the additional costs of a compatible hybrid inverter and installation. There may also be additional costs and switchboard upgrades, especially if dedicated circuits are required to be backed up during a blackout. The battery location is also important and some households may require dedicated enclosures or covers to be installed to help protect the battery from extreme weather and direct sunlight, which could result in overheating and shutdown. In many cases, the warranty may be void if the battery is not installed in a semi-protected location.

    Solar and battery cost calculator

    Our free solar and battery calculator, shown below, can help you quickly calculate the optimum size solar and battery system for your home or business. Note, you will want to FOCUS on the shorter winter months to ensure you have enough excess solar energy to charge the battery in winter.

    Solar Battery Comparison Chart

    Below is a comparison table of the most popular AC-coupled, add-on battery systems including upfront cost per kWh of battery capacity. AC coupled battery options can be retrofitted to existing solar installations; these include the popular Tesla Powerwall 2, Sonnen ECO and Senec batteries. On the other hand, a huge range of modular DC-coupled battery systems are available for on-grid and off-grid solar systems but must be installed with a compatible hybrid or off-grid inverter. See all our detailed battery comparison charts including DC-coupled batteries.

    Off-grid battery systems

    Off-grid systems require a much greater battery capacity (generally from 12kWh to 30kWh) along with dedicated off-grid inverters and other equipment, so the cost to go off-grid is generally much higher. As a general guide, the Powerplus Energy, GenZ, BYD, Simpliphi or Zenaji batteries are a few of the best options due to their compatibility with the leading off-grid inverters. For more details and information see our comprehensive off-grid solar systems review.

    Do you need a battery?

    Unless you experience frequent blackouts the answer is generally no. For many people, the cost of a battery system is simply too high, but this doesn’t mean you can’t take advantage of rooftop solar. For most households, rooftop solar can reduce your electricity bills by up to 60% or more depending on the amount of energy you use during the day. For example, it is possible to run energy-intensive appliances such as dishwashers, air-conditioners and washing machines for free using your solar energy during the day.

    In most states, you will receive credits for any excess electricity fed back to the grid. The feed-in credit (FiT) rate is usually around 0.10 per kWh but was recently reduced to 0.06 in some states. This is much lower than the cost of electricity, which is on average 0.30 per kWh in Australia; hence why is it worthwhile using your solar to run appliances or heat hot water during the day while it is being generated.

    The payback period or return on investment (ROI) for most battery systems is around 8-12 years. With this in mind, it’s generally more cost-effective to install rooftop solar and run efficient appliances or heat hot water during the day rather than store excess energy in a battery. However, for some people the value and security of having a reliable, sustainable power supply easily outweighs the cost.

    Detailed home battery cost comparison

    For a full in-depth comparison of the cost of purchasing a home battery system plus the operating cost over the life of the battery, see our detailed home battery storage guide.

    Do Batteries Qualify for the Solar Tax Credit in the Inflation Reduction Act?

    Pairing battery storage with solar is a means of ditching your utility bills and becoming energy independent – but is do batteries qualify for the solar tax credit?

    Absolutely! The signing of the Inflation Reduction Act put into immediate effect the 30% Residential Clean Energy Credit, which applies to the cost of solar equipment and labor including battery storage.

    This new and improved tax credit for solar batteries applies to battery projects installed in 2022 and remains at 30% through 2032.

    Let’s dive in to see how this incentive works and how you apply it to your solar or battery installation.

    As with any tax decision, please consult your CPA or tax advisor before filing. This article has been prepared for informational purposes only.

    First off, are we sure batteries qualify for the new solar tax credit?

    Yes. We know it’s been a roller coaster ride waiting for a climate bill that would expand solar and battery incentives. But the ride is over and battery storage definitely qualifies for the 30% federal tax credit, in addition to solar, wind, geothermal heat pumps, and fuel cells.

    The Inflation Reduction Act (IRA) was signed into law on August 16, 2022 and it specifically addresses the Residential Clean Energy Credit for “qualified battery storage technology expenditure” in Section 13302.

    Essentially, the IRA amended the schedule for the previous tax credit so it would remain at 30% for solar and battery equipment “placed in service” after December 31, 2021 and before January 1, 2033.

    Not only is the 30% Residential Clean Energy Credit effective immediately, it also applies retroactively to solar and battery storage installed any time in 2022. So if you purchased solar and/or battery in 2022, your available federal tax credit increases from 26% to 30% of the gross cost of the project.

    Does All Battery Storage Qualify for the Federal Tax Credit?

    OK, so there is clearly a 30% tax credit for solar battery storage. But what counts as a “qualified battery storage technology expenditure?”

    To qualify for the 30% tax credit, battery storage must be:

    • “Installed in connection with a dwelling unit located in the United States and used as a residence by the taxpayer”
    • “(Have) a capacity of not less than 3 kilowatt hours.”

    According to the bill, the 3 kilowatt-hour minimum battery capacity doesn’t take effect until 2023. Considering the average battery installation is closer to 10kWh, most batteries will easily exceed the minimum amount to qualify for the solar tax credit.

    And notice that there are no maximum size, price, or tax credit qualifications. You can enjoy a 30% tax credit on as large of a battery system as you’d like – but bigger isn’t always better. Let’s see how applying the federal tax credit for battery storage works.

    Does standalone battery qualify for the Residential Clean Energy Credit?

    Beginning on January 1, 2023, standalone battery storage (batteries that aren’t connected to solar panels) will also qualify for the 30% Residential Clean Energy Credit.

    Standalone battery can serve as a backup energy source for homeowners that face frequent power outages due to natural disasters and Public Safety Power Shutoffs. If you face frequent, short outages, standalone battery is a great alternative to a gas generator.

    Standalone battery can also help you save money by storing electricity for when it’s more affordable to use. Through Time-of-Use (TOU) rates, the price of electricity changes throughout the day and can be significantly more expensive during peak demand (typically morning and evening). In some instances, the price difference between peak and off-peak periods can be 25 cents per kilowatt-hour — or roughly 2.50 cents per day. Battery storage can help you shift grid usage from high- to low-cost periods and add up to substantial savings.

    Can I get the tax credit for battery if I already used it for solar?

    Although the IRS and Department of Energy have yet to issue guidance on the matter, it appears homeowners will be able to claim the Residential Clean Energy Credit for adding battery storage added to existing solar systems.

    For example, if you purchased solar in 2022 and claimed the tax credit for it, you could add battery storage in 2023 and claim the tax credit for that, too.

    Applying the Federal Tax Credit for Solar Battery Storage

    It’s important to note that the Residential Clean Energy Credit is a nonrefundable credit that can be used to lower your federal tax liability.

    What does that mean? It means the tax credit is not a check that comes in the mail. Rather, it’s a credit that can be used to reduce your federal tax liability beginning in the same tax year that your battery was installed and deemed operational by a government inspector.

    Let’s run a few example scenarios:

    Scenario 1: Your Tax Liability Exceeds Your Tax Credit

    Let’s say you spent 50,000 on a solar and battery installation in 2022. You would be eligible for a 15,000 tax credit. Then when tax season rolls around you have 17,000 in tax liability. The full 15,000 credit can be applied at once to reduce that liability to 2,000.

    Scenario 2: Your Tax Credit Exceeds Your Tax Liability

    Let’s say you bought the same system as above and received the same tax credit for 15,000. However, in this scenario you only have 8,000 tax liability. You can use your Residential Clean Energy Credit to bring down the 8,000 tax liability, and then you can carry over the remaining 7,000 to the next tax year.

    The IRS currently states that the Residential Clean Energy Credit can be carried forward for as long as it’s active, which is until December 31, 2032. This video explains the basics of using your federal tax credit.

    As with any tax decision, please consult your CPA or tax advisor before filing. This article has been prepared for informational purposes only.

    Is Solar Battery Storage Necessary?

    It’s natural to wonder whether or not getting a battery is needed. And honestly, it depends on your situation and needs.

    Each homeowner will have different reasons for getting their system, and a battery brings a lot of additional value to a solar system. The main benefit is having a reserve of energy to power your home through blackouts and Planned Safety Power Shutoffs (PSPS) that are becoming more common as extreme weather events increase in frequency and intensity.

    There’s also the benefit in becoming energy independent, as pairing a battery with solar essentially creates your own mini utility.

    Finally, in areas where net metering isn’t available through local utilities, battery storage can be used to bank solar electricity to be used at night and when sunlight is hard to come by.

    The bottom line

    A vast majority of batteries installed between 2022 and 2032 will qualify for the solar tax credit expanded by the Inflation Reduction Act. The only qualifications specified by the Inflation Reduction Act are that the battery must be installed in a taxpayer’s residence in the US, and the capacity of the battery storage must exceed 3 kWh.

    The 30% tax credit can be used to reduce your tax liability and can be carried forward if it’s not all used at once.

    Even though it’s available for the next 10 years, solar and battery storage are long-term investments, so the sooner you invest, the sooner you’ll enjoy a return.

    Interested in Solar Panels? Here Is Some Advice.

    Buying a solar energy system can be expensive and confusing. Here are some things to think about if you are in the market for solar panels.

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    Thanks to technological and manufacturing advances, costs for solar panels have tumbled in the last decade, making solar energy more popular for homeowners. But figuring out how to add a solar energy system to your roof can be daunting.

    Workers installed a solar and battery system this winter at my home in a New York City suburb. It was a major investment but has already begun paying off in lower utility bills and providing peace of mind that we will have at least some electricity during power outages, which are common here because storms often knock down power lines.

    Interest in rooftop solar systems is high and growing as energy rise and concerns about climate change mount. Many people are also worried about blackouts caused by extreme weather linked to climate change. A Pew Charitable Trust survey in 2019 found that 6 percent of Americans had already installed solar panels and that another 46 percent were considering it.

    “The biggest thing is that solar is a lot cheaper than it used to be even in places like New York City and Boston, where it tends to be more expensive than in the suburbs,” said Anika Wistar-Jones, director of affordable solar at Solar One, an environmental education nonprofit in New York City that helps affordable housing and low-income communities adopt solar energy.

    If you are interested in solar, here are some things to consider.

    Can you add solar panels to your roof?

    This question might seem simple, but finding the answer can be surprisingly complicated. One installer told me that my roof was so shaded by trees that solar panels would not generate enough electricity to make the investment worthwhile. Hearing another opinion was worth it: The installer I hired allayed those concerns and recommended some tree trimming. On sunny days my system often generates more power than my family uses.

    It can also be difficult to find out what your local government and utility will permit because the information is usually not readily available in plain language. I learned that lesson at my previous home.

    When I lived in New York City, it took months of research to learn that I couldn’t install panels on my roof. The city requires a large clear area on flat roofs like mine for firefighters to walk on, it turns out. And I couldn’t install solar panels on a canopy — a rooftop framework that elevates the panels — because it would violate a city height restriction for homes on my block.

    clean, energy, reviews, solar

    The best approach is to cast a wide net and talk to as many solar installers as you can. You might also consult neighbors who have put solar panels on their roofs: People in many parts of the country have banded together in what are known as solarize campaigns to jointly purchase solar panels to secure lower from installers.

    “That has been really successful in neighborhoods and communities all across the country,” said Gretchen Bradley, community solar manager at Solar One.

    Can I afford a solar installer?

    You should seek proposals from several installers. Comparison shopping services like EnergySage and SolarReviews make it easy to contact multiple installers.

    When reviewing proposals, pay attention to how much the system will cost per watt. This tells you how much you are paying for the system’s electricity-generating capacity and allows you to compare offers.

    The median quote for new rooftop solar systems is 2.75 per watt, according to EnergySage. That works out to about 26,125 for an average system of 9,500 watts before taking into account a federal tax credit. For the 2022 tax year, the credit stands at 26 percent of the cost of solar system; it is slated to drop to 22 percent in 2023 and end in 2024. Many states, including Arizona, California, New York and Massachusetts, also offer residents incentives to install solar systems, such as rebates and tax breaks.

    can vary greatly because of location, local labor costs and other factors, like what kind of home you live in and whether other work is needed before installation. If your roof is old or damaged, for example, it might need to be replaced before a solar system can be installed.

    Rooftop solar systems can reduce monthly utility bills, depending on electricity rates, how much energy a home uses and state policies. Systems that save more money will help buyers recoup their investment faster. Vikram Aggarwal, the chief executive and founder of EnergySage, said solar systems should ideally pay for themselves within 10 years.

    The excess electricity that rooftop systems produce is sent to the electric grid, and utilities typically compensate homeowners for that energy through credits on their monthly bills. The value of those credits varies by state.

    How should I pay for it?

    If you can afford to buy a solar system outright, you will get the best deal by paying cash. Systems purchased with loans or through leases tend to cost more, especially over the life of the contract. Shopping around is your best hedge against falling prey to dubious or predatory agreements.

    The main advantage of leasing a solar energy system is that your costs are typically fixed for the duration of the contract. But experts caution that leases can be hard to get out of and could become a burden when you sell your home, because buyers might not want to take on your contract.

    Mr. Aggarwal noted that leases “make sense” for some people who may not earn enough to claim the federal tax credit. He suggested that people interested in solar leases get three or four quotes from different installers.

    Should I buy a battery?

    Adding a battery to your solar system will allow you to store some of the excess electricity it generates to use during a blackout or in the evening and night. A solar system without a battery will not keep you supplied with power during an outage because most residential systems are automatically turned off when the grid goes down.

    Batteries can be expensive, especially if you want to run large appliances and provide power for many hours or days. A 10- to 12-kilowatt-hour battery, which can store roughly a third of a home’s typical daily electricity use, costs about 13,000, according to EnergySage.

    The federal tax credit for rooftop solar systems applies to the costs of batteries that are purchased with solar panels or if they are added in a following tax year. About 28 percent of residential solar systems installed in 2021 included batteries, up from 20 percent in 2020, according to a survey by EnergySage.

    The Wirecutter, a product recommendation service from The New York Times, has a detailed guide for buying solar and battery systems.

    Can I use my electric car as a backup battery?

    Most electric cars cannot provide power to homes. Only a few models, like the Ford F-150 Lightning and the Hyundai Ioniq 5, have that ability, and they are in incredibly short supply.

    But many energy experts believe that it will eventually be common for car batteries to send power back to homes and the electric grid.

    In many parts of the United States, extended power outages may happen just once or twice a year. As a result, Mr. Aggarwal said, it may not make sense to invest in an expensive home battery, which usually holds much less energy than electric-car batteries. “Everybody is starting to talk about using your car to run your home.”

    If I can’t install solar panels, can I still buy solar energy?

    You might be able to join a community solar project, which are usually installed on open land or on the roofs of warehouses and other large buildings.

    While the rules vary by state, community solar programs generally work in similar ways. Members get two bills a month: one from the community solar project and one from their utility. The projects sell electricity at a discount to the rate charged by your utility, and each kilowatt-hour of power you buy shows up as a credit for a kilowatt-hour of energy on your utility bill.

    New Yorkers who join a community solar project, for example, can save about 10 percent on their monthly electricity bill, Ms. Bradley said. “It doesn’t cost anything to sign up or leave a project,” she added.

    While most states allow community solar, a majority of such projects are in just four states — Florida, Minnesota, New York and Massachusetts — according to the National Renewable Energy Laboratory.

    You can search for projects in your area on websites including EnergySage and PowerMarket or through state agencies, like the New York State Energy Research and Development Authority.

    `An earlier version of this article referred incorrectly to the timing of a tax credit for the cost of batteries on a home solar energy system. Taxpayers can claim the credit for the batteries in a tax year after the year in which they installed the solar panels; it is not the case that solar panels and batteries must be purchased in the same year to qualify for the credit.

    How we handle corrections

    Vikas Bajaj, an assistant editor in the Business section, was previously a member of the editorial board and a correspondent based in Mumbai, India. Before that, he covered housing and financial markets from New York. @ vikasbajaj

    A version of this article appears in print on. Section B. Page 1 of the New York edition with the headline: Going Solar? Here’s What You Need Order Reprints | Today’s Paper | Subscribe

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    Solar Battery Buying Guide: Everything You Need to Know

    Want to go off the grid or earn energy bill credits? Adding a battery to a solar panel system may be the answer. Here’s what you need to know.

    Taylor Freitas is a freelance writer and has contributed to publications including LA Weekly, Safety.com, and Hospitality Technology. She holds a B.A. in Print and Digital Journalism from the University of Southern California.

    Laura Leavitt is a personal finance and wellness writer for CNET. Her work has been published at NextAdvisor, Bankrate, The Simple Dollar, MoneyGeek, Business Insider and more.

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    Full energy independence isn’t achievable without solar batteries.

    Solar panels can generate electricity only when the sun is shining. But with solar batteries, you can store that energy for use at night, during an outage or to sell it back to your utility or apply as bill credits.

    Backup solar batteries run on electricity and can either work as a standalone device or as part of a home solar system. When the lights go out, your backup battery system will automatically switch on and serve as source of electricity for several hours, a day or longer.

    If people have solar as well as a battery, they can use the solar in the day to feed their houses and charge their batteries. And at night, the batteries will serve their houses instead of the grid, Kim Quirk, a branch manager at ReVision Energy, told CNET recently. It makes people a bit more independent from the grid when we tend to see big spikes.

    However, all of these benefits come at a cost. Installing a battery backup system can be a significant investment, so it’s important to understand what’s involved. For this guide, we’ve answered some of the most common questions about battery backup systems, including how they work, how they’re made, how much they cost and where you can buy them.

    How solar batteries work

    When your home doesn’t need all the energy being produced by your solar panels, the excess energy is stored in the battery. When the solar panels aren’t generating enough energy to fill the power needs of the building, the battery discharges reserve power to make up the difference.

    The way you configure your solar battery system affects how it works. You have three main options:

    • Connect to your solar panels: Batteries connected to solar panels will fill and discharge frequently in response to the times without sun that you still want electricity. This is useful when in an area that is off-grid, away from electrical utilities.
    • Connect your solar panels to a solar battery system andto the grid: You can choose to fill your battery and just keep it as a backup, rarely discharging it, and mostly selling and buying excess electricity from the electric company.
    • Use battery duringtime of use ratespikes: If you live in an area where electricity rates vary with the time of day, you can configure your system to use battery backup at the most expensive times and to buy electricity from the grid at the least expensive times.

    Benefits and drawbacks of battery backup systems

    Whether you have solar panels or not, battery backups offer plenty of benefits. For starters, they help you gain energy independence, so you don’t have to rely on the public power grid. This is especially critical if you live somewhere with frequent outages or blackouts.

    On top of that, battery backups don’t operate on fossil fuels and provide your home with clean energy. Unlike generators, they’re nearly silent to run and don’t emit carbon into the atmosphere.

    Even if the power hasn’t gone out, you can use your battery backup as a way to save money on your electric bills. For example, if you’re on a time-of-use utility plan, you can draw on the energy from your battery during peak hours rather than paying sky-high electricity rates to your energy company.

    Pros of solar batteries

    • Energy independence
    • Save money on energy bills
    • Less or no reliance on utility
    • Power your home during an outage
    • Clean energy

    Cons of solar batteries

    • Expensive, sometimes as much as a solar system
    • High upfront costs
    • Limited capacity

    Different types of solar batteries

    There are several kinds of batteries used in battery backup systems, including lithium-ion, lead-acid and flow batteries. Here’s a quick overview of each type.

    Lithium-ion batteries

    Lithium-ion batteries are the most common for home systems. Most of today’s popular battery backup products are lithium-ion, including the Tesla Powerwall, Panasonic EverVolt and Generac PWRcell. They’re lightweight and energy-efficient, making them perfect for home use.

    Lead-acid batteries

    Lead-acid batteries have been used for hundreds of years and are the primary type of battery used in cars. They’re cheaper than lithium-ion, but they aren’t as efficient, which means they’re best suited for small systems.

    Flow batteries

    Flow batteries (or redox flow batteries) are less common in home systems since they’re mainly designed for commercial use. However, the technology appears promising, and it could become more widely used in residential battery backup systems in the near future.

    Nickel-cadmium batteries

    Nickel-cadmium batteries have a high energy density with double the energy of a lead-acid battery. Nickel-cadmium batteries are very durable, expensive and work well in extreme temperatures making them a good choice for large-scale commercial and industrial projects. Cadmium is toxic, however, and generally not appropriate for residential use.

    Buying a backup battery system

    You can get battery backups from a range of businesses, including manufacturers, solar companies and battery retailers. CNET curated a list of the best batteries here. The price will depend on which battery model you choose and how many you buy for your system. According to the US Department of Energy, solar batteries can cost anywhere from 12,000 to 22,000.

    If you’re buying a battery backup as part of a solar panel system, however, you may qualify for a rebate or tax credit.

    How to set up a battery backup system

    Once you’ve decided on a battery or batteries, make sure to have it professionally installed.- otherwise, you run the risk of injuring yourself. You can expect to pay a few thousand dollars for installation (which is separate from the cost of the battery).

    Maintaining a battery backup system

    After the initial setup, there’s little maintenance required on a battery backup system. You won’t need to replenish a fuel source (like you would with a generator), and there’s no need for regular maintenance.

    Lifespan and warranties

    A few years after installation, you may notice that your battery backup system doesn’t hold a charge as well as it used to. That’s because, like other types of batteries, battery backups lose storage capacity over time.

    To account for this, battery backups include a warranty that expresses how efficient the battery should be by the end of the warranty period. Many of the top solar batteries offer 10 years and 70%, meaning that by the end of the 10-year warranty, the battery should still operate at 70% of its original performance.

    Inverters and batteries

    Inverters play an important role in how the battery stores and converts solar energy. While solar panels generate electricity in direct current, or DC, the electric grid and homes generally use alternating current, or AC. An inverter can convert AC to DC or vice versa, and most solar batteries include an inverter to store the energy in DC form, as well as an inverter to convert it back into AC to be used in the grid or the home.

    Because inversion of current isn’t perfectly efficient, battery producers are always experimenting with how to invert less often and increase the efficiency of the battery. As a result, some batteries will not have inverters for both input and output included in the system. Talk to your solar installer about the battery system you’re considering so that you can make sure you have all the external inverters you need.

    Solar Battery Guide: Benefits, Features, and Cost

    Generating clean, green energy for your home using solar panels helps you save money, use less fossil fuel, and reduce your environmental impact. Whether you’re thinking about installing a new solar power system, or you’ve already gone solar, battery energy storage can help you leverage the full potential of your solar panels. By storing the excess energy your solar panels produce, solar-plus-storage provides a reliable, low-cost power backup option so when the sun goes down, the clouds roll in, or the lights go off in your community, you always have power on hand and savings in store.

    In this article, we’ll look at how solar batteries work, and then dive into solar battery cost and what you can expect to pay, solar battery benefits and why you should consider adding storage to your solar power system design, solar battery features and what to compare when looking at different solar battery options, and solar battery types so you know the advantages and disadvantages of each solar battery material. Our goal is to help you decide what the best solar storage options are for your home.

    How Does A Solar Battery Work?

    Consider your home’s energy needs on a typical day: Usually, a home requires more energy in the morning when people are getting ready, and at night when more appliances and electronics are in use. During the day when people are away from their home, power demands go down, but these are actually the most productive hours of the day for your solar power system, when it is generating the most electricity. Therefore, the ratio of energy production to energy consumption is highest during the day, meaning there is excess power being generated.

    If you don’t have an energy storage solution, that excess power is being fed back to the grid, and you might get some credit for it if your utility supports net metering. Alternatively, you can add a solar battery to your solar power system, and store this surplus renewable energy to use when needed to power your home. Solar batteries work by storing the excess energy produced by your solar panels, and then feeding that excess energy back into your system when needed. Solar batteries can either store excess energy as DC electricity that’s produced by your solar panels, or they can store AC electricity that’s already been converted by your inverter.

    Can you go off-grid with a solar battery?

    The short answer is that even with solar battery storage, going completely off-grid is usually not worth the extra cost and complexity. Staying connected to your utility gives you more options for where to get electricity, and you can install a much smaller solar power system that will cost a lot less, and still save almost as much money as you would with a much larger system, where most of that excess capacity goes unused most of the time.

    To go completely off-grid, you need enough solar battery storage to last for multiple days of typical usage, and you need enough solar panels to both power your home, and keep those solar batteries charged at all times. It might be possible during the summer months when there’s plenty of power being generated, but when winter rolls around and your solar panels have fewer hours of sunlight to generate electricity with, it’s going to be difficult to generate the excess electricity you’d need to keep enough in reserve. No one wants to stress over how much electricity you have stored up, and whether or not it can last through multiple days of storms and cloudy weather!

    By staying connected to the grid, you’ll always have a backup source of electricity when needed, and you can use your solar power when it’s available to power your home, without stressing about what happens when production is lower than average. Adding a solar battery while staying connected to the grid gives you even more control over your electricity, and helps use the full capacity of your solar panels without letting any excess electricity go to waste.

    What are the benefits of adding a solar battery to your solar power system?

    There are a variety of solar battery benefits that homeowners consider when deciding to integrate energy storage into their solar power system design:

    • Energy Independence. Perhaps the ultimate reason for why you might want a solar battery installation. Solar energy storage technology enables you to have more control over where your energy comes from, how it gets used, and what you can do with it.
    • Increase Your Savings. By drawing power from your solar battery, you can still use the more affordable electricity that your solar panels produce, even at night or during a storm. If you live in an area where electricity depend on time-of-use metering, you can save even more by drawing power from your solar battery when the utility companies charge higher rates during the night or peak hours.
    • Better For The Environment. By increasing the energy-producing potential of your solar PV system, you can reduce your fossil fuel usage even more, reducing your environmental carbon footprint, and supporting technologies that will help continue the international drive towards a better climate future.

    Electricity During Storms, Severe Weather, and Other Power Outages

    The grid power supply can be affected by seasonal storms and other severe weather conditions that lead to power outages, sometimes extending for hours or even days. A good example is the huge winter storm that hit Texas in mid-February 2021, causing power outages for at least 4.5 million customers. To add insult to injury, some Texans were even stuck with huge utility bills as some electricity rates skyrocketed more than 7,000% in a matter of days.

    Another example of severe weather leading to large-scale power outages was the massive 2019 wildfires in California. than 2 million customers were left without power after the utilities turned off the grid to prevent high winds from knocking down power lines and starting even more wildfires.

    Having solar battery storage added to your solar power system can save you the stress of having to experience similar occurrences in the future, as you can use the power that’s stored in your battery, even if the rest of the grid is experiencing a blackout. With climate change causing more severe weather and larger and even more destructive storms, it’s a safe bet that large-scale blackouts will continue to be an issue in the coming years.

    How much energy can be stored in a solar battery?

    The energy that a solar battery can store is measured in kilowatt-hours (kWh), and different manufacturers produce batteries that can hold varying amounts of power. For example, the Sonnen Eco is available in capacities that range from 5 kWh all the way up to 20 kWh in a single battery.

    In addition, most solar batteries can be linked together or installed in an interconnected design to offer a larger combined storage capacity if your needs are higher than what a single battery can provide.

    How do solar batteries fit into the larger electric grid?

    At peak hours of the morning and evening, demand on the electric grid increases drastically, as more people are at home using more electricity. (This change in demand is called the “duck curve”.) The increased demand causes utilities to scale up their electricity generation at power plants, and the sudden rise in demand at certain hours of the day may cause disruptions, and there are risks of oversupply.

    Basically, utilities have to be prepared for peak demand, and a lot of their electricity generation potential goes unused when demand is lower. Building this excess electricity generation capacity is expensive, and leads to higher utility rates as a result.

    Adding solar batteries to home solar PV systems can help flatten the demand curve, so the grid can be designed for more typical usage and doesn’t need to be built for surges and spikes. During the day when demand is lower, solar panels can charge solar batteries, and then when demand increases, solar batteries can help supply the extra power that’s needed, so it doesn’t have to be generated by the utilities. Therefore, solar battery storage plays a crucial role in streamlining grid power production and distribution, and can better align utility capacity with normalized demand.

    How much does it cost to add a solar battery to your home?

    Your solar battery cost depends on a variety of factors, including power rating, depth of discharge capability, round-trip efficiency, and the warranty that’s provided, but the biggest factor is the capacity of the battery. Typically the bigger the solar battery, the higher the cost.

    A good rule-of-thumb for solar battery cost is that the cost per kilowatt-hour ranges from 400 to 750. Therefore, a typical home solar battery is going to cost between 10,000 and 20,000, including installation costs. Depending on your energy usage and storage needs, you may be able to “stack” multiple batteries for greater storage capacity. If you need multiple batteries, the cost for the entire battery backup system might be higher.

    How Net Metering Credits Affect Solar Battery Economics

    Net metering is when the utility gives you credit for excess electricity that your solar power system generates and feeds back into the grid. Net metering basically turns the power grid into your home’s backup battery, although the economics of net metering compared to battery storage are going to be different, unless you receive the same credit from the grid when providing electricity as you pay when receiving electricity. (This is called ‘true net metering’, and is not offered by many utilities).

    Utilities generate electricity at a very large scale, so they can generate it for much less than they charge for it. As a result, even when a utility gives net metering credit for electricity they receive from a homeowner, they want to credit the homeowner the same rate that they can generate it for themselves.

    For example, a utility might charge 0.12 per kWh for the power drawn from the grid, but only give credits worth 0.05 per kWh when you feed the grid. This means that if you get credit for electricity that you add to the grid, but then you have to buy it back later at a higher cost, you end up paying 0.07 more for the same electricity that you could have saved into a solar battery system when you generated it. Therefore, it’s often more economical in the long run to add solar battery storage to your home instead of using net metering credits, because you can capture the full value of any excess electricity that your system generates.

    How Time-of-Use Metering Credits Affect Solar Battery Economics

    Time-of-Use (TOU) rates refer to electricity rates that vary depending on the time of day that the electricity gets used. Usually, rates are highest during peak hours (mornings and afternoons/evenings) and lowest during the day when solar panels are producing the most electricity. Therefore, if you live in an area with TOU rates, you can leverage your solar battery benefits by storing the additional solar energy generated when the rates are low, and using it during peak hours when rates are high, instead of paying for grid power.

    How Demand Charges Affect Solar Battery Economics

    Demand charges are when the electricity rate your utility changes depends on how much electricity you use. The more you use, the higher the rate. The rates may also depend on the amount of electricity you use during peak hours when power demand is higher. This policy is meant to encourage homeowners to reduce their total electricity usage.

    If you have solar power and can store excess energy in a solar battery, you can significantly decrease the amount of energy you use from the grid, so you’ll pay even less for electricity from utilities with demand charges, because your total electricity usage will be much less.

    Are tax credits offered for the purchase of a solar battery?

    There’s no single answer to the question, “Are there tax credits available for solar batteries?” because it depends on where you live, and how your solar power system is designed.

    While installing a solar panel battery, you might qualify for various financial incentives from federal and state governments. For example, as long as the batteries you install are charged by solar (and not by the grid), they are eligible for the solar tax credit, which saves you 30% off the total cost of installation. Tax credits are directly applied to your tax bill, making it a Smart way to save while acquiring an effective way to store solar energy.

    In addition, some states like California have rebates specifically for batteries for solar panels that can significantly reduce the cost of acquiring them, through incentives like the Self-Generation Incentive Program (SGIP). Other states like Maryland have also passed an income tax credit for energy storage systems in recent years.

    Solar Battery Features To Consider When Comparing Storage Options

    There’s no easy answer to the question, “What is the best battery for solar storage?” because each battery has pros and cons that you should compare. Before you decide which solar battery option is right for you, you’ll want to consider the four key solar battery features: Capacity and Power, Depth of Discharge, Round-Trip Efficiency, and Warranty.

    Capacity and Power

    Comparing solar battery power and capacity is usually the first step in determining which solar battery is the best match for your family’s needs.

    Solar battery capacity is the amount of power a battery can store, measured in kilowatt-hours, or kWh. Solar battery capacity determines how long you can power your home with the energy stored in the battery. (Keep in mind that most home solar batteries can be “stacked” to include multiple batteries in a single installation, so you can increase their overall storage capacity.)

    Solar battery power rating is what tells you how much power the battery can deliver all at once, measured in kilowatts. Having a battery with a large capacity is great, but you also need to know how much of that capacity you can access at any one time. The higher the power rating, the more devices you can power at the same time.

    A battery with a low capacity and a high power rating means the battery is capable of powering many appliances at once, but for a short period of time. In contrast, a battery with a high capacity and a low power rating can only power a few electronic appliances at once, but it can do so for an extended amount of time.

    Power and capacity isn’t an either/or comparison, and a good battery can offer both a large capacity and a high power rating, so you’ll want to just keep an eye on both features and find the right combination for your family’s needs.

    Depth of Discharge (DoD)

    Depth of Discharge is the maximum percentage of a battery’s capacity that can safely be used without the need for a recharge. Draining a battery completely can actually damage the battery, so the Depth of Discharge helps you understand how much of a battery’s total capacity can actually be used.

    For example, a battery with a 10 kWh capacity and 90% depth of discharge rating tells you that you shouldn’t use more than 9 kWh (90% of 10 kWh) before recharging to avoid damaging the battery and shortening its lifespan. The higher the Dept of Discharge, the more of your battery you can actually use on a day-to-day basis.

    Round-Trip Efficiency

    When a battery stores or distributes electricity, some energy turns into heat during transmission, and some is needed to run the technology inside of the battery itself, so it’s not possible to draw back the same amount of energy that you feed into a solar battery. Therefore, round-trip efficiency measures the percentage of energy you can get back from a battery, compared to what the solar panels feed into the battery. For example, if you feed 10 kWh into your battery, but you can only get 8 kWh back, the battery has an 80% round-trip efficiency.

    Warranty

    The warranty terms help you determine how long you can expect a solar battery to last. Think about your cell phone — have you noticed that as it gets older, it just doesn’t hold the same charge as it did when it was new? Solar batteries are just like the battery in your cell phone, only much bigger.

    Warranty terms specify the number of cycles (one cycle = one charge and discharge) that the battery should last, as well as the capacity it should retain, before the warranty expires. As the battery’s cycles increase, its ability to retain a charge decreases. For example, you might get a 10 year, 5,000 cycle, 70% capacity warranty, which means that if the battery is less than 10 years old and has had less than 5,000 cycles, it should have at least 70% of its original capacity remaining.

    The warranty that comes with a battery impacts the price of that battery. Typically, more expensive batteries are going to include longer or better warranty terms, and that warranty can prevent you from dealing with issues down the road as your battery gets older.

    What is the battery life of a home solar battery?

    The features of the battery you choose will determine how long your solar batteries last, and what the battery life is expected to be. For instance, how quickly the capacity rating of the battery decreases determines how long it can be used before needing a replacement. The typical home solar battery has a battery life between 5 and 15 years before the performance of the battery is reduced enough that it will need to be replaced.

    What is the lifespan of a home solar battery?

    Generally, the solar battery lifespan you can expect is between 5 and 15 years. As with most batteries, a solar battery’s lifespan can be increased with proper maintenance, such as making sure that it operates at specified temperatures, doesn’t discharge beyond its Depth of Discharge limit, and maintains a proper charge level when not in use.

    What materials are home solar batteries made from?

    Most people who want to know, “What are the different types of solar batteries?” are looking to compare the different battery materials. Solar batteries can be manufactured from lithium-ion, lead-acid, and even saltwater. Each material has different characteristics, with advantages and disadvantages.

    Lithium-Ion

    Home solar batteries made with lithium-ion are made with the same chemical composition used to create mobile phone, laptop, and electric vehicle batteries. Lithium-ion solar batteries like Tesla Powerwall and sonnenCore are popular for their compact design, higher Depth of Discharge rating, and extended lifespan compared to lead-acid batteries. Because of these benefits, lithium-ion batteries are typically more expensive than other solar battery types, but this initial investment can pay off over time.

    Lead-Acid

    Lead-acid batteries are similar to the battery type found in most gas-powered vehicles, and have been used for decades as solar storage options, though they are now typically used in more DIY storage solutions. Lead-acid batteries are significantly cheaper than other solar battery types, but they have a shorter lifespan and lower Depth of Discharge rating. Lead-acid batteries also have less capacity than lithium-ion batteries, so multiple batteries are usually connected together into a solar battery bank to provide enough storage, making the installation more complicated.

    Saltwater

    Saltwater batteries are relatively new to the energy storage market, and as the name implies, they use saltwater as the electrode to store energy. The key benefit of a saltwater battery is that they don’t use heavy metals (lead and lithium) that require a careful disposal process once the battery is no longer being used to store electricity. Saltwater batteries can be recycled, which makes them more eco-friendly. However, saltwater storage is still a new and unproven technology, and no company is currently selling saltwater battery technology at a large scale for home use.

    Where can I get the best solar battery?

    Palmetto has been helping thousands of homeowners across the US access clean solar energy for more than a decade. Our end-to-end solutions promise results that you can track, and savings you can count on. With many years of experience designing solar power systems to maximize your savings, we have the knowledge needed to precisely determine which solar energy solution will work best for your home.

    If you’re considering adding solar to your home, visit the Free Solar Savings Estimator which will automatically forecast your future savings if you decide to go solar — based on your current utility bill, the specific programs and incentives that are in your area, and other factors. We even take into account variables like the Residential Clean Energy Credit, and how much that tax credit can save you if you add solar to your home. Getting your free estimate is the easiest way to compare options, and get the best solar energy solution for your home, so we look forward to helping you get started on a journey towards energy independence.

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