Keep your lights on, refridgerator running, and WiFi connected when Washington’s grid fails with a backup battery.
Power’s out?
You didn’t notice.
Your whole home battery kicks on instantly, handling every outage before you even know one started.
Save money with battery incentives
Washington Sales Tax Exemption
When paired with solar, you won’t pay state or local sales tax on your system, cutting thousands off your total cost.
Expires end of 2029
PSE Flex Program
Get financial rewards for helping stabilize Washington’s energy grid with your home backup battery system.
Apply anytime
PSE Enhanced Incentives
Receive up to $10,000 towards the upfront cost of your battery if you qualify. Earn up to $1,000 per battery plus $.50 per kWh for your participation during Flex events.
We can help you apply
What is the PSE Flex Battery Program?
Get rewards from Puget Sound Energy for improving grid stability with your home backup battery system by enrolling in the PSE Flex Battery Program.
Earn money
Enroll and earn up to $1,000 per battery, plus up to $500 per battery each year with no action required.
Protect the environment
Pair batteries with solar to further reduce your environmental impact.
Enhance your community’s energy stability
Take strain off the power grid during high-energy use periods and increase your community’s energy resilience.
Already have solar?
Solar and batteries make the perfect pairing. Solterra can install backup batteries compatible with your system so you can maximize your solar value with integrated storage.
Power during an outage
For safety reasons, grid-tied solar systems automatically power down during outages. Pairing solar with battery storage allows your system to safely “island” from the grid, keeping your home powered and your solar working when utilities fail.
Store the excess energy you produce
Your solar panels often generate more electricity than your home uses during the day. Backup batteries capture that excess energy so you can use it later, like at night or when the grid is down.
Transform your solar system into a complete energy solution
Adding battery storage gives you more control over your energy. With Solterra’s expertise, your existing solar becomes smarter, more flexible, and ready for whatever the grid throws your way.
Power outages are on the rise across Washington
Seattle’s rapidly aging electrical infrastructure is increasingly vulnerable to strain and failure.
More frequent extreme weather
From bomb cyclones to ice storms to tornado warnings, Seattle is experiencing unprecedented extreme weather due to climate change.
Record-high energy demand
Seattle’s booming population, the push toward electrification, and energy-intensive technologies like generative AI data centers are driving unprecedented demand for electricity across Washington. Meanwhile, new energy infrastructure is struggling to keep pace.
Recent energy policy changes
Shifting federal energy policy is throttling American clean energy production at a time when energy prices and demand have never been higher. In response, more Washington homeowners are taking control of their own energy by switching to solar and installing backup battery power.
Solterra customers enjoying seamless backup power
Derek Monner
Woodinville, WA
“We lost grid power for 3 full days, but our Enphase solar and battery system kept the lights on, the refrigerator running, and the TV powered up.”
Dwight Bickel
Edmonds, WA
“My solar panels and home battery worked well during the recent huge windstorm. My wife posted on Facebook that we didn’t lose power. I posted in reply ‘grateful for our battery backup,’ because we lost power twice, 5 min and 25 min, but my wife did not notice!”
Solterra is Washington’s leading battery expert
A Seattle-based, certified woman-owned installer, Solterra brings nearly two decades of industry experience to every high-quality, affordably-priced solar and battery installation.
Exceptional customer experience
Our customer-first, educational approach empowers you to make the right decision for your needs—no added pressure, ever.
Warranty-backed craftsmanship
Our durable, efficient, and aesthetically-pleasing installations are backed by our comprehensive, 10-year warranty.
Local expertise
We’ve completed thousands of installations in Western Washington and handle every detail from design to final walk through.
See why customers love Solterra
Everything about the Solterra experience was exceptional.
Katie Robinson
Seattle, WA
This is a rare company that delivers on everything it promises.
Allan Geller
Sammamish, WA
I cannot express how pleased we are with the process and final product.
Mark von Ehrenkrook
Puyallup, WA
We’re experts at what we do, and so are our partners.
Franklin aPower 2*
Franklin’s 15 kWh capacity is enough to power most single-family homes; option to add additional batteries for more backup power.
*Eligible for PSE Flex Program!
Enphase IQ Battery 10C*
Enphase’s modular design allows you to customize your backup capacity in 10 kWh increments (10–80 kWh) to match your home’s needs.
*Eligible for PSE Flex Program!
Discover which battery backup is right for you
It starts with a simple, free consultation—everything you need to make the right decision without any of the pressure.
Learn about solar
How does solar work?
Solar panels absorb energy from the sun and convert it into clean, reliable electricity for your home, EV or business.
How much does solar cost?
From federal and state incentives to long-term savings potential, solar is a smart financial investment.
Does solar work in Washington?
Long summer days and our state’s net metering policy helps solar outshine the competition— even on cloudy days.
Frequently asked questions
What is a solar battery backup system and how does it work?
A battery backup system stores electricity from the grid when power is available, then automatically provides that stored energy to your home during an outage or when the grid is unstable. It keeps your essential appliances running smoothly—no noisy generator or manual switch needed. When paired with a solar system, the battery can also store the clean energy your panels produce during the day, allowing you to power your home with renewable energy even after the sun goes down.
How long can a battery backup power my home during an outage?
That depends on your battery size, how much energy you’re using, and which appliances you want to keep running. Most homeowners can expect anywhere from 1–3 days of backup power for essentials like lights, Wi-Fi, refrigerator, and key outlets. Larger systems with multiple batteries can extend that runtime even further.
What are the benefits of adding battery storage to my solar system?
Adding battery storage gives you more control over your energy. You can use your own stored power when rates are highest, during peak hours, or when the grid goes down. It increases your energy independence, improves your home’s resilience, and can help lower your utility costs over time—all while making the most of your existing solar investment.
Will I still have power if the grid goes down?
Yes—if you have a solar battery backup system. Standard grid-tied solar systems shut off during outages to protect utility workers. But with a properly configured battery system, your solar panels and battery can continue powering your home safely and automatically when the grid is offline.
How much does a solar battery system cost?
On average, a professionally installed battery backup in Seattle ranges from $1,200 to $1,700 per kilowatt-hour (kWh) of storage capacity for the first battery and $700 to $1,000 per kWh for additional batteries. For example, a 15 kWh battery system might cost between $13,000 and $25,500.
The first battery includes the smart control system that manages your solar, battery, and grid connection, along with all necessary wiring for home integration. Additional batteries are easy to add and offer a cost-effective way to extend your backup power during an outage. Additionally, state and local utility incentives can help reduce the upfront cost.
Can I add a battery to my existing solar system, or do I need to upgrade it?
In most cases, yes—you can add a battery to your current solar setup. We’ll evaluate your system’s inverter and wiring to make sure they’re compatible. Sometimes, a simple equipment update is all that’s needed to integrate a battery smoothly and safely.
How long do solar batteries last, and what kind of maintenance do they need?
Most high-quality lithium-ion solar batteries last 10 to 15 years, with warranties typically covering 10 years or a specific number of charge cycles. They require little to no regular maintenance—just occasional system monitoring, which we can handle remotely or through your app.
Why choose a battery backup instead of a gas generator?
Battery backup systems offer clean, quiet, and maintenance-free power without the fuel costs, noise, or exhaust of a gas generator. They turn on instantly and automatically during an outage, and can recharge from either the grid or your solar panels—no refueling required. Over time, a battery system provides a safer, more reliable, and environmentally friendly way to keep your home powered.