Solar Panels vs. Solar + Battery Storage: Which Is Right for You?

Published April 8, 2026  ·  7 min read

Solar panels without a battery are already a complete system. Your panels generate electricity during the day, you use what you can, and any surplus flows to the grid. Your meter tracks the exchange. At the end of the month, you pay only for the net difference.

A battery adds a layer to that. Instead of sending surplus power to the grid, you store it in a battery for use at night or during an outage. That sounds appealing, and it is in the right circumstances. But it adds significant cost and does not improve your finances in every situation. Understanding when it helps — and when it does not — is the core of this decision.

What a battery actually does

A home battery system is a large rechargeable unit installed in or near your home, usually in a garage or on an exterior wall. It charges from your solar panels during the day and discharges at night or when the grid goes down. The two main reasons homeowners add one are saving money and having backup power.

Those two goals are related but not the same. A battery can provide backup power regardless of whether it saves you money. And it can save you money without being particularly useful for backup, depending on how it is configured. Be clear about which goal matters most to you before evaluating the financial case.

What it costs

A typical residential battery system runs $12,000 to $18,500 installed. The most common unit, the Tesla Powerwall 3, holds 13.5 kWh and costs $15,300 to $16,200 before incentives. Competitors include the FranklinWH aPower 2 (15 kWh, 15-year warranty), the Enphase IQ 5P (modular, works with Enphase solar only), and the LG Home 8 (14.4 kWh, stackable up to four units).

Average installed cost across brands runs around $1,100 to $1,300 per kWh of storage capacity, according to data from EnergySage. Tesla offers the lowest cost per kWh for larger systems because expansion units ($5,900 each) add 13.5 kWh without duplicating the inverter. If you are targeting 27 kWh or more of storage, Tesla is typically the most cost-effective option.

One important note on incentives: the 30% federal battery tax credit that applied to homeowner-purchased systems expired December 31, 2025, along with the solar credit. There is no federal credit for homeowners buying a battery in 2026. State programs remain active in several states — California's Self-Generation Incentive Program (SGIP), Connecticut's Energy Storage Solutions program (up to $16,000), New York's Clean Energy Standard storage program, and Colorado's battery incentives can each make a meaningful difference. Check your state's programs at DSIRE before getting quotes.

The financial case: it depends on your net metering situation

The single biggest factor in whether a battery makes financial sense is how your utility handles excess solar production.

If you are in a state with full retail net metering — New Jersey, Massachusetts, New York, Maryland, Connecticut, and several others — your utility already credits exports at the same rate you pay to buy electricity. The grid is effectively acting as a free battery. Every kilowatt-hour you send out during the day comes back at night at full value. Adding a physical battery does not improve that exchange. It adds $15,000 or more to your system cost and typically extends your payback period by three to six years without producing meaningful additional savings. In these states, a battery is primarily a backup power device, not a financial investment.

If you are in a net billing state, the math changes. California's NEM 3.0 reduced export credits to just 5 to 8 cents per kilowatt-hour, down from around 30 cents. If you export surplus solar during the day and then buy power back at 22 to 26 cents per kilowatt-hour in the evening, that gap is costing you every day. A battery closes it by letting you store your own power and use it when rates are highest. In California under NEM 3.0, a well-sized battery can achieve payback in 4 to 7 years — making it nearly as financially attractive as the solar system itself. Arizona, Nevada, and Indiana have similar dynamics at a smaller scale. See our Net Metering 101 guide for the full state-by-state picture.

If your utility charges time-of-use (TOU) rates, a battery can make sense even in net metering states. About 40% of US utilities now offer TOU pricing, where electricity costs two to three times more during evening peak hours (typically 4–9 PM) than during off-peak hours. A battery charged by solar during the day and discharged during peak hours captures that price spread. In areas where the peak-to-off-peak spread exceeds 20 cents per kilowatt-hour, batteries can achieve payback in six to eight years through daily rate arbitrage alone.

The backup power case

Standard grid-tied solar systems shut down during power outages for safety reasons, even if the sun is shining. Your panels will not power your home during a blackout unless you have a battery with island mode capability.

If you live in an area with frequent grid outages — whether from severe weather, wildfire-related Public Safety Power Shutoffs (PSPS) in California, or an aging grid — backup power has real value beyond the financial calculation. A 13.5 kWh battery can run essential loads (refrigerator, lights, Wi-Fi, phone charging) for 12 to 24 hours, or power critical medical equipment or a home office throughout an outage. The value of that depends entirely on your situation. For a household where losing power means losing income or creates a health risk, the backup value alone can justify the cost.

Installing together vs. adding later

If you decide to add a battery, timing matters. Installing a battery at the same time as your solar panels is meaningfully cheaper than adding one later. When both are installed together, the electrical work — wiring, panel upgrades, permitting — is completed once. Adding a battery to an existing solar system typically costs $1,500 to $3,000 more in labor and equipment than installing at the same time.

There is a middle path: install solar now and have your installer run the wiring for a future battery. This "battery-ready" configuration adds a few hundred dollars upfront but preserves the option to add storage later without a full reinstall. If you are undecided, this is a reasonable approach.

Which battery brands are worth knowing

• Tesla Powerwall 3 is the best-known option, with 13.5 kWh capacity, 11.5 kilowatt (kW) continuous output (enough to run most whole-home loads), and a 10-year warranty. Cost-effective at scale if you need multiple units. Note: Tesla has faced some availability challenges and its recent product recall (Powerwall 2 units over fire safety concerns) has led some homeowners to consider alternatives.
• FranklinWH aPower 2 offers 15 kWh of usable capacity, a 15-year warranty, and strong generator integration — useful if you want battery and generator backup working together. Generally considered the strongest overall alternative to Tesla.
• Enphase IQ 5P is modular (5 kWh per unit, stackable) and integrates tightly with Enphase microinverter solar systems. If you are installing an Enphase solar system, this is worth serious consideration. It does not work outside the Enphase ecosystem.
• LG Home 8 offers 14.4 kWh per unit, stacks up to four units (57.6 kWh total), and is priced competitively. A solid choice for larger homes or those who want significant storage capacity.

How to decide

Start with these three questions:

• What does your state pay for excess solar? If it is full retail rate, a battery is likely a backup device for you, not a financial tool. If it is below retail — especially if you are in California, Arizona, or Nevada — a battery can meaningfully improve your solar ROI.
• Does your utility offer time-of-use rates? If yes, and the peak-to-off-peak spread is over 15 cents per kWh, a battery is worth modeling. Ask your installer to run the numbers for your specific rate schedule.
• How much do you value backup power? If outages are rare and your home has no critical power needs, the backup value is low. If outages are common, or if losing power carries real costs — medical equipment, home office income, food loss — the backup value is real and worth factoring in.

For most homeowners in net metering states with stable grids, solar panels alone deliver better financial returns than solar plus battery. The battery conversation changes if you are in a net billing state, on TOU rates with a meaningful peak spread, or in an area where grid reliability is a genuine concern.