Best Home Battery Storage Options: 2021 Guide

By Frank Jossi, Rise Writer

Last Updated: Feb 24, 2022

Ever since Tesla introduced the Powerwall battery a few years ago, more than a few homeowners have wondered what the buzz was all about. For solar array owners, the appeal of lithium battery storage makes sense. On sunny days, residential solar arrays often generate enough electricity to power a home. They have enough left over to sell back to the local utility.

Are Home Batteries Worth It?
How Many Batteries Are Needed to Power a House?
Are Lithium Batteries Better Than Lead Acid?
What Are Time of Use Home Batteries?
Which Home Battery Is Right for Me?
Can Home Batteries Save You Money?
How Much Is a Solar Home Battery?
What Are the Best Home Battery Options?
Solar Rebates and Incentives

Are Home Batteries Worth It?

The idea that the power could be stored and used later, rather than sold back to the grid, will become a more attractive option. Home storage batteries can help you cut your electricity bill, especially if you live in a sunny state. However, a home can only get to Net Zero energy by being powered with clean energy captured by solar panels and stored in batteries.

Stored electricity could fill the tank of an electric car or keep the lights on in homes and neighborhoods where the electric grid has gone down. This is the idea behind making your home more resilient. In addition, it can keep some essential electric-powered items, like your refrigerator and freezer, running in the event of natural or human-made disasters that are becoming more frequent.

As that same grid becomes more sophisticated, homeowners may even have opportunities to sell their energy to utilities during high-demand times, such as 5 p.m. to 8 p.m.

Solar-powered batteries have been around for a while. However, they are still a young but rapidly growing market now as manufacturers continue to ramp up production to meet increasing demand. No one company dominates the market; here's a look at the current marketplace. (Note: Rise has written about battery options; since prices continue to change and the market evolves, we are revisiting this topic.)

Be wary of marketing statements about how many days of power the battery offers, as that is entirely dependent on how much energy your home requires so that it can vary widely. The key to sizing is understanding how much power you will be using/drawing from the battery. Some homeowners see batteries to get off the grid, but that’s an unlikely scenario, at least with lithium batteries. These batteries typically only hold enough energy to power an average American home for hours, not days.

Connecting to the grid, however, isn’t always the best option either. Your solar panels will be giving back to the grid during the daylight hours when most of us are at work. In addition, many electric companies charge premium prices during peak hours, usually during the daytime and early evening. This means that the electricity from the grid that you do use overnight will most likely be charged to you at a lower rate if you have a time of use billing.

How Many Batteries Are Needed to Power a House?

The amount of battery storage required is based on your home's energy usage. Energy usage is measured in kilowatt-hours over some time—for example, a home requiring 1,000 watts for 10 hours per day = 10 kWh per day. When calculating, you need to consider the battery's performance and how much continuous output you require. It's essential to consult with a solar energy professional to size the panels and batteries for your needs properly.

Are Lithium Batteries Better Than Lead Acid?

It would take several lithium-ion batteries to power a home for a day or more. Lead-acid batteries, which have been around for decades, are less efficient, offer less storage, are often larger, and do not last as long. Lithium batteries can be left at a partial charge without any adverse effects.

What Are Time of Use Home Batteries?

Having stored energy could be helpful in other applications. A handful of utilities have time-of-use (TOU) rates that make customers pay more for electricity during high-demand times. With a home battery, a homeowner could switch to stored energy during high demand periods to reduce the amount of electricity they buy from their utility and reduce the average cost per kilowatt-hour (kWh) they are charged. If you need to recharge your electric vehicle (EV) during that same high-demand time, you could use stored electricity rather than depend on expensive utility power.

But outside of California, TOU rates are not typical, although many utilities are testing TOU programs of their own. Currently, most utilities apply “net metering” rates to solar households, offering to buy their electricity at a per kilowatt charge equal to what they charge for power. For example, let’s say you sell electricity for 11 cents a kilowatt-hour (kWh) to your local utility. It’s likely in many states that the utility charges you the same rate when it sells you electricity. In this case, which is a more typical net metering situation, electricity storage offers no financial benefits.

Which Home Battery Is Right for Me?

While battery technology is still in its infancy, a breakthrough came with lithium-ion batteries. These batteries–the same kind found in cell phones and many other devices–capture energy from solar panels as direct current (DC) and convert it through an inverter to alternative current (AC), the kind used in American homes.

Several flavors of battery storage exist: DC-coupled systems, AC coupled systems, AC battery systems, and hybrid converter systems. Considering the complexity of the options, ask your battery installer which system will work best with your solar array and the infrastructure of your local utility.

Generally, AC battery systems such as the Tesla Powerwall 2 and the Enphase Battery are popular with homeowners who have no desire to live off the grid. The AC coupled systems offer affordability and ease of installation. In addition, the more sophisticated hybrid converter system, such as LG Chem RESU, allows for high voltage lithium batteries.

Batteries can be sized to serve the size of your home and your solar arrays. A larger home may need a larger battery. Again, consult a clean energy expert and electrician to ensure the sizing works and the system will meet your expectations.

Can Home Batteries Save You Money?

The good news is that utilities are evolving their pricing mechanisms. A handful of states have begun to employ “avoided costs” to pay for electricity produced by residential solar installations, including Nevada and Hawaii. Avoided costs reimbursements are much less, as little as 4 cents kWh. At that rate, using the power you stored will save money, making storage a more desirable option.

In addition, utilities have begun marketing programs offering cheaper overnight electricity rates for EV owners. But for some EV owners looking to have the flexibility to charge at high-demand times, a lithium battery can serve as a less expensive option than buying energy from their utility at, say, 6 p.m.

How Much Is a Solar Home Battery?

Home battery prices below do not include installation, which can range from $2,000 to nearly $20,000 for one or more batteries. It’s not a purchase every solar array owner needs to make. Still, for those looking to be on the cutting edge of innovation or live in areas where utilities have creative rate structures, a battery could be a wise investment.

What Are the Best Home Battery Options?

While it's difficult to compare models, we've taken the extra step to look at the price per kilowatt-hour (kWh). For context, the average U.S. home uses about 30 kWh per day.

Tesla’s Powerwall 2

Each Tesla Powerwall 2.0 lithium-ion battery provides 13.5 kWh of electricity and costs $6,700 each, plus $1,100 for supporting hardware. So, that equates to $578 per kWh. In addition, the Tesla website has a tool that lets you properly size your system based on your home's size. The tool even accounts for the critical energy-intensive appliances you choose to support.

Tesla Powerwall 2 Specs

7kW peak / 5kW continuous
Floor or wall-mounted rechargeable lithium-ion battery options with liquid thermal control
Dimensions: 45.3" x 29.6" x 5.75"
Weight: 114kg
Recommending Operating Temperature: -4°F to 122°F / -20°C to 50°C
Scale up to 10 Powerwall's
Sleek, wall-mounted design installed indoors or out
10 Year Warranty
Cloud-based web and mobile control and monitoring

LG CHEM RESU10H

The South Korean-based LG Chem RESU 6.4EX storage system is a lithium-ion battery. The RESU10H is available for sale in North America, sized at 9.8 kWh, and costs $5,250.00.

LG CHEM RESU10H Specs

Total Energy 9.8kWh 400VDC
Max Power: 5.0 kW / Peak Power 7.0 kW (for 10 sec)
Voltage Range: 430-550 Volts
Capacity: 63 Ah
Easy wall-mounted or floor-standing installation
Dimensions: 29.30 x 35.70 x 8.10 inches
Weight: 220.00 lbs
10 Year Warranty

Pika Energy Harbor

Pika Energy designs a wide variety of batteries; the Harbor pairs directly with the inverter, is a smart lithium-ion battery, and ranges in size from 10.1 to 20.3 kWh. The 10.1 kWh system costs $13,500, coming in at $1,336 per kWh.

Pike Energy Harbor Specs

Total capacity, Harbor 3 = 10.1kWh up to Harbor 6 20.3kWh
Up to 10kW of instantaneous power
DC Current: Input/Output: 24A
The DC-coupled design eliminates lossy power conversions
Recommending Operating Temperature: 54-86°F
10 Year Warranty

Sonnen Eco

The Sonnen Eco Batterie, based in Germany, is a lithium ferrous phosphate battery; its smallest size starts at 4 kWh and costs $9,950—coming in at almost $2,500 per kWh. If you size it up to 10 kWh, the price tag is $16,750, which drops the per kWh price to $1,675 per kWh—still quite a premium over the competition. Why? It includes an inverter and smart energy management software, differentiating itself as a more fully integrated system.

Sonnen Eco Specs

Complete storage system, everything included and ready to connect
Sonnen eco output: 2.5 – 3.3 kW
5 kWh – 15 kWh storage capacity
Expandable in steps of 2.5 kWh
10,000 charge cycles
10 Year Warranty

Panasonic 11.4 kWh EverVolt

The Panasonic EverVolt enables seamless installation with new and existing solar panel systems or generators. The EverVolt app allows you to manage consumption, backup power, net metering, charge/discharger, and more in real-time. EverVolt's pre-programmed Time-Of-Use (TOU) helps you manage energy use and costs. EverVolt can is available in several sizes ranging from 5.7 kWh for $12,705 to 17.1 kWh for $19,055. The Panasonic EverVolt is the mid-tier offering from Panasonic that costs $15,880.00. The warranty guarantees at least 60% minimum capacity at the end of the warranty period.

Panasonic 11.4 kWh EverVolt Specs

13.5 kWh total energy
11.4 kWh usable energy
4.8 kW continuous battery output power
5.5 kW maximum continuous power
84% / 89% round-trip efficiency
6 hours of backup capability
Recommending Operating Temperature (charge): 41°F to 131°F [5°C to 55°C]
UL certified
10 Year Warranty

Nissan XStorage

The auto manufacturing giant Nissan has a solar backup battery option called the Nissan XStorage. This battery comes in three different sizes. The 4.2 kWh system costs $3,700, while the broadest choice of 9.6 kWh costs just under $10,000. Many of these battery options are factory refurbished electrical vehicle batteries giving a useful second life to the millions of EV batteries produced in the coming years.

Nissan XStorage Specs

Power range from 3.6 kW to 6 kW
Nominal capacity from 4.2 kWh to 10.08 kWh
Can be wall or floor mounted
5 to 10-year warranty depending on model
Stocks both grid and renewable energy during the day

Enphase Encharge 10

The Enphase Enchage is an all-in-one AC-coupled storage system, a Lithium iron phosphate (LFP) costing $10,649.97 without installation. Enphase offers a smaller Encharge 3 for $3,979.97, which may be adequate depending on your needs. The Encharge 10 offers output (AC) at 240 VAC, 3.84 kVA AC continuous power, and is rated for 16 A of output current. Its touted benefit is that it works seamlessly with Enphase micro-inverters; because of its small size, it’s not intended to help homeowners go off-grid.

Enphase Encharge 10 Specs

10.08 kWh total usable energy capacity
Twelve embedded grid-forming microinverters with 3.84 kW Ten-year limited warranty
Grid-forming capability for backup operation
Mobile app-based monitoring and control
Passive cooling (no moving parts/fans)
Lithium iron phosphate (LFP) chemistry for maximum safety and longevity
Ten-year limited warranty

Solar Rebates and Incentives

Incentives exist for homeowners who want to invest in battery technology, often in conjunction with solar installations. A 26 percent tax credit exists for solar battery buyers, too, though to get the entire credit, the energy stored must come entirely from the sun—and the system must be in place by the end of 2020. According to EnergySage, the average solar shopper saves at least $5,000 thanks to the solar tax credit. In 2021, the tax credit drops to 22% before expiring in 2022.

As the federal government’s incentive expires, some states consider tax credits for batteries, among them California, Maryland, and Massachusetts. Keep your eye on your local state legislature as a new tax credit for solar storage may be on the way. You can use our Find Rebates tool to look for solar rebates in your area.

Disclaimer: This article does not constitute a product endorsement however Rise does reserve the right to recommend relevant products based on the articles content to provide a more comprehensive experience for the reader.Last Modified: 2022-02-24T13:11:39+0000

Article by:

Frank Jossi

Based in St. Paul, Frank Jossi is a journalist, editor and content strategist. He covers clean energy in Minnesota for Midwest Energy News and writes frequently for Finance & Commerce. His work has appeared in more than 70 local, national and international publications.