Solar panels are one of the best financial decisions a homeowner can make. But most homeowners do not realize that a grid-tied solar system goes completely dark during a power outage, even on a bright sunny day. The reason is a mandatory safety mechanism called anti-islanding protection, required by UL 1741, which shuts down solar systems when the grid fails to prevent electricity from flowing back into power lines where utility workers are making repairs. The result: more than 5 million solar installations across the US go silent during blackouts despite having panels on the roof.
A solar battery changes that equation entirely. It stores the energy your panels produce during the day and makes it available at night, during outages, and any time you want to avoid drawing from the grid. Solar Energy World installs four battery systems: Tesla Powerwall 3, FranklinWH aPower2, Enphase, and SolarEdge. This article covers how batteries work with solar, why more homeowners are adding them, what each system does, and how to decide which option fits your home.
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Why battery storage is becoming standard
According to the Solar Energy Industries Association, 40% of new residential solar installations in 2025 included battery storage, up from 28% the year before. That shift is not driven by technology novelty. It is driven by a grid that is becoming less reliable at the same time electricity costs are rising.
The US Energy Information Administration reported that Americans experienced an average of 11 hours of power outages in 2024, nearly double the annual average across the previous decade. Hurricanes Beryl, Helene, and Milton alone accounted for 80% of those lost hours. A JD Power survey found that 45% of utility customers nationwide experienced at least one power outage in the first half of 2025, and the average length of the longest outage increased from 8.1 hours in 2022 to 12.8 hours by mid-2025. In the South, which includes Solar Energy World’s Florida service territory, the longest outages in the first half of 2025 averaged 18.2 hours.
Climate Central’s analysis of federal outage data found that weather-related power outages in the US from 2014 to 2023 were approximately double the frequency of the 2000 to 2009 period. The trend is consistent and upward.
For homeowners in Maryland, Virginia, Delaware, Pennsylvania, New Jersey, Washington D.C., and Florida, the combination of hurricane risk, ice storms, and an aging grid infrastructure makes backup power a practical consideration rather than a luxury. A 2022 Lawrence Berkeley National Laboratory study found that a 10 kWh battery paired with solar can get virtually all homes through a three-day outage without heating or cooling, and met 86% of the power load for three days in homes using heating and cooling. That is real, measurable resilience.
What a solar battery does for your home
A battery paired with solar serves three distinct purposes: backup power during grid outages, savings from time-of-use rate optimization, and increased use of your own solar energy rather than the grid’s. The value of each depends on where you live and how your utility bills you.
Backup power during outages
When the grid fails, a battery-equipped solar system detects the outage and automatically transitions the home to stored battery power. Solar panels continue charging the battery during daylight hours, creating a self-sustaining energy source for as long as the sun is available. During a three-day outage, a well-sized battery-solar combination can keep the refrigerator, lights, internet, sump pump, phones, and medical devices running continuously.
Unlike a generator, a battery operates without fuel, without noise, and without exhaust. There is nothing to maintain, no fuel to store, and no carbon monoxide risk. When a storm is forecast, systems like the Tesla Powerwall’s Storm Watch and the Enphase Storm Guard automatically charge the battery to maximum capacity before the weather arrives.
Time-of-use rate optimization
Many utilities in Solar Energy World’s service states charge more for electricity during evening peak demand hours and less during off-peak hours. A battery stores solar energy produced during the day and discharges it during the expensive evening peak period, replacing grid electricity at the highest-rate hours with stored solar energy from earlier in the day. In areas with time-of-use pricing, this strategy can save $300 to $1,200 per year depending on the size of the system and local rate structures.
Maximizing solar self-consumption
Without a battery, excess solar energy produced during the day goes back to the grid at the net metering credit rate. In some states and utility territories, that export rate is lower than the retail rate the homeowner pays when drawing from the grid in the evening. A battery stores that excess daytime production so the homeowner uses their own solar power at night instead of buying from the grid, increasing the household’s energy self-sufficiency and reducing the reliance on fluctuating utility prices.
The Solar Energy World battery lineup
Solar Energy World requires that solar panels have been installed on the home by Solar Energy World to qualify for battery installation. Battery storage is not offered as a standalone product for homes with panels installed by a different company.
This requirement exists to protect quality and performance. The battery system needs to integrate properly with the existing solar inverter, electrical panel, and monitoring infrastructure. Because every Solar Energy World installation uses specific equipment and wiring standards, the in-house team can guarantee the integration works as designed.
Tesla Powerwall 3
The Powerwall 3 is the most widely used home battery in the US. Tesla installed its one millionth Powerwall unit globally in 2025. At 61% of the EnergySage Marketplace battery share in the second half of 2025, it is the benchmark against which most other residential batteries are measured.
Each Powerwall 3 unit stores 13.5 kWh of usable energy and delivers 11.5 kW of continuous power output, enough to support most whole-home loads including HVAC. It includes an integrated solar inverter with six MPPT channels, which means the battery and solar system work as a single unit without the need for a separate string inverter. This simplifies installation and reduces the number of components in the system.
The Powerwall 3 uses Lithium Iron Phosphate (LFP) chemistry, which is considered the safest lithium battery chemistry available. LFP cells do not carry the thermal runaway risk associated with older lithium battery technologies, and the unit is designed to operate in temperatures from -4°F to 122°F.
Up to four Powerwall 3 units can be stacked per system for a total of 54 kWh. Powerwall 3 Expansion units add 13.5 kWh of storage without the cost of additional inverter hardware, making larger configurations more affordable per kWh. The Tesla app handles monitoring and control, tracking production, consumption, battery charge level, and savings in real time.
Tesla backs the Powerwall 3 with a 10-year warranty guaranteeing at least 70% of original capacity, meaning the battery will hold a minimum of 9.45 kWh after a decade of use. Installed cost runs approximately $15,300 to $16,200 per unit before incentives in 2026.
The Powerwall 3 is well suited for homeowners who want whole-home backup from a single unit, those whose solar systems already use Tesla equipment, and those who value a brand with wide installer familiarity and a strong support network. Solar installers named the Powerwall 3 the easiest battery to install in the 2025 Solar Industry Survey.
FranklinWH aPower2
The FranklinWH aPower2 has the highest capacity of any single battery unit Solar Energy World installs: 15 kWh of usable storage per unit with 10 kW of continuous power output and a 15 kW peak that can start a 5-ton air conditioner.
Where the Powerwall 3 includes an integrated inverter, the aPower2 uses FranklinWH’s aGate controller, a universal energy management hub that works with any inverter brand, including SolarEdge, Enphase, SMA, and standard string inverters. This makes the aPower2 a flexible option for homes with existing solar systems using a variety of inverter configurations.
The aPower2 is built on LFP chemistry, the same safe, non-toxic battery chemistry as the Powerwall 3. It comes with a 15-year warranty covering 60 MWh of throughput, equivalent to approximately 4,000 full discharge cycles. This is among the longest residential battery warranties available and a meaningful differentiator from the Powerwall 3’s 10-year coverage.
The system scales significantly: up to 15 aPower2 units can be integrated per aGate controller, for a maximum of 225 kWh. For most homes, a single aPower2 provides adequate backup for essential and heavy-duty loads simultaneously. For larger properties or high-demand applications, the system can grow without replacing the core equipment. Installed cost runs approximately $12,000 to $16,000 per unit before incentives.
The FranklinWH aPower2 is well suited for homeowners who want maximum storage capacity from a single unit, those with larger homes or heavier energy loads, homeowners whose solar system uses a non-Tesla inverter, and those who place priority on the longer warranty term.
Enphase battery
The Enphase battery pairs naturally with Enphase microinverter systems, which Solar Energy World installs across many projects. Homeowners who already have Enphase microinverters benefit from a fully integrated system managed through the Enphase app, the same platform used to track solar production panel by panel.
The Enphase system is modular by design, allowing homeowners to start with one battery and add capacity over time as energy needs change. Storm Guard automatically prepares the battery for severe weather conditions. For homeowners who want to begin with a smaller investment and scale up gradually, or who prefer managing everything through a single app ecosystem, the Enphase battery is a natural fit.
SolarEdge battery
The SolarEdge home backup solution integrates directly with SolarEdge inverter systems and is compatible with LG Chem RESU high-voltage batteries. It provides full or partial home backup automatically when the grid goes down, and maximizes solar self-consumption on a normal day by storing unused daytime production for later use.
For homeowners whose Solar Energy World installation uses a SolarEdge inverter, the SolarEdge battery offers the tightest integration, with a single monitoring and control interface across the entire system.
Choosing the right battery for your home
The right battery depends on four factors: how much backup power you need, which inverter your solar system uses, how your utility charges for electricity, and your budget.
If whole-home backup during multi-day outages is the priority, the Powerwall 3 or aPower2 are the right starting points. Both can handle HVAC, appliances, and critical loads simultaneously. The Powerwall 3 offers a simpler single-unit solution with an integrated inverter. The aPower2 offers more storage per unit, a longer warranty, and compatibility with any inverter.
If your solar system uses Enphase microinverters and you want a single app to manage everything, the Enphase battery gives you that integration. If your system uses SolarEdge, the SolarEdge battery offers the same seamless compatibility.
If your utility uses time-of-use pricing with significant peak rate differences, the financial case for any of these batteries is stronger. If your utility still offers full one-to-one net metering, the financial benefit is primarily in backup power and self-consumption rather than rate arbitrage.
It is generally more cost-effective to add a battery at the same time as the solar system installation. Permitting, inspection, electrical work, and labor costs overlap significantly when both are installed together. Adding a battery later is possible but typically costs more per unit of storage installed.
Battery storage incentives in 2026
The federal Section 25D residential clean energy credit expired December 31, 2025 and is no longer available for homeowner-purchased battery systems in 2026. Homeowners who installed a qualifying battery before the deadline and have not yet filed their 2025 taxes should consult a tax professional.
Third-party-owned systems, including batteries under a lease or PPA, may still qualify for the commercial Section 48E credit through 2027. This credit belongs to the system owner, not the homeowner, but competitive providers pass some savings through as lower rates.
State and utility incentives vary by location. Solar Energy World’s in-house incentive specialists review every applicable program at the time of installation and handle enrollment on the homeowner’s behalf. You can explore solar incentives in your state to see what programs are currently available in your area.
What stays the same regardless of which battery you choose
Every Solar Energy World battery installation is performed by the same in-house W-2 workforce that installs the solar panels. No subcontractors. Every installation is supervised by a NABCEP-certified solar designer and a licensed master electrician. The battery integrates with the Solar Energy World monitoring app, so battery charge level, usage patterns, and energy flow data appear alongside solar production and consumption data in a single platform.
Service requests for battery-related issues are filed through the same app and handled by Solar Energy World’s in-house service team, the same people who installed the system.
Get a free solar and battery estimate
Solar Energy World offers free in-home and virtual solar estimates that include battery storage options for homeowners across Maryland, Virginia, Delaware, Pennsylvania, New Jersey, Washington D.C., and Florida. Your estimate includes a review of which battery system fits your existing or planned solar setup, a full breakdown of applicable state and local incentives, and a comparison of financing options. To learn more about solar battery storage and what it can do for your home, start there.
