Battery Backup Power
The next generation of battery storage has arrived, giving solar customers clean, reliable, and efficient backup power that also lessens their daily dependence on the power grid.
Grid-tied solar electric systems are a great way to save money using free power from the sun. However, most grid-tied solar arrays are designed to shut down when they lose grid connection. When you pair solar electricity with battery storage, you can supply critical loads in your home, or even function as a grid independent “energy island.”
ReVision Energy is a Tesla Powerwall Certified Installer, which means we offer a customized solar-plus-battery solution that enables you to access the free, abundant power of the sun at your home and reduces your reliance on fossil fuels. We have Tesla Powerwall available now across our geographic region of Maine, New Hampshire, Massachusetts, and parts of Vermont.
How Battery Backup + Solar Power Works
Battery or Generator – Which is better when the power goes out?
Home standby generators tend to be the norm in New England for backup power in utility outages, but with ease of operation, and the ability to be recharged by solar, a battery pack is an increasingly attractive option:
|Advanced battery energy storage system||Fossil Fuel-Powered Home Standby Generator|
|Maximum peak power (kW)||4.5 – 21 kW||7-10 kW|
|Energy Storage||10.6 – 40.5 kWhr||Depends on tank size|
|Duration||Forever, if solar is available||Until the fuel runs out|
|Backup the whole house||Possible but usually we design critical loads only for longer run-times||Yes|
|Backup critical loads forever||Yes – just add sun!||No, limited by fuel tank|
|Noise||Quiet – (as loud as refrigerator)||Loud – (as loud as a city street)|
|Service required||None||Annual service: oil change and filters|
|Warranty||10 years||0-2 years|
|Internet-enabled||Yes, included in cost||No|
|Future smart home ready||Yes||No|
|Future smart grid ready||Yes||No|
|Provides protection against solar regulatory changes||Yes¹||No|
|Requires weekly ‘exercise’ to be available||No||Yes|
|Net Installed Cost||$10,000 – $25,000+²||$7,000|
|Plus gas install||N/A||$500|
|Annual service cost (est)||None||$200|
|Annual fuel cost (est)||None||$300³|
|Expected system life||15||12|
|Total cost for 10 years||$10,000 – $25,000+²||$18,250|
¹ Installing energy storage provides some mitigation of risk associated with future Net Metering uncertainty and other rate design risk by allowing a customer to maximize self-consumption, minimize demand charges or optimize energy use patterns for a possible Time of Use rate.
² Net Cost: Assumes storage is charged by a solar energy system and so is eligible for the 30% federal tax credit. Multiple units will be required for extended runtime or higher capabilities so price range will vary accordingly. Not shown here are state incentives which exist in some areas.
³ Assumes 100 G a year at $3/G propane
While there are some limits to its power output capabilities, the battery pack is infinitely cleaner, can run indefinitely under proper design circumstances, has no recurring maintenance needs, and offers a range of capabilities—such as “self-consumption” of solar power and grid support services—not offered by generators. As technological evolution and fierce competition push down the sticker price of battery backup units, we expect the next 3-5 years will show a seismic acceleration in the adoption of residential battery systems.
What Customers Say
Kristen and Josh of Rochester, NH had a Powerwall installed and wrote us to say:
“Going solar had been a dream for us since we bought our house 10 years ago, but we really wanted to store our energy, too. With the Tesla battery, and our panels, we were able to make that dream a reality! We love that we are able to teach our daughter about alternative energy while providing a cleaner, greener future for her!”
We also spoke with Kate Olson and Matt Cheney who paired a Powerwall with their solar array at their 1870 farmhouse in Freeport, Maine:
“We live in a relatively rural area where there are power outages. A lot of people get generators for backup, but we’ve never wanted to do that.
Unlike a generator, the Powerwall is completely silent and powers on in a fraction of a second during a grid outage.
For us, we’re excited about capturing energy and creating electricity in general but then there is something nice about feeling like you’re actually using the solar energy you are producing rather than throwing it out to the grid.”
Future-Proof Solar Investments
ReVision Energy has been following the developments in home battery backup technologies for years. In the early days, the only kind of solar energy systems were off-grid (battery-only) systems, and then with the advent of grid-tied inverters, the obvious benefits of tying up to the grid became clear.
Now, technology has come full-circle, and a grid-tied solar customer can enjoy the benefits of being tied to the grid, with the resilience and independence of having battery support.
Customers who want to maximize the financial savings of their solar investment can start with a straight grid-tied array for maximum savings and lowest upfront cost, then invest later in a home battery backup solution when they are ready. While there is great battery technology on the market already, we expect that this segment of solar technology will rapidly improve over the next 5-10 years.
Learn More About Home Battery Backup & Energy Storage
ReVision Energy strives to stay at the top of all trends in renewable energy, and solar backup power is one of the hottest topics right now. Our engineers worked with our editorial team extensively for an in-depth, three-part series on the state of battery backup storage and its implications for the homeowner, and the grid, writ large. Though originally published in 2016, the history of the development of battery capabilities and analysis of the core technology of modern battery storage remains fresh: