Battery Backup

Say goodbye to power outages.

Tesla RevealThe next generation of battery storage has arrived, giving solar customers clean, reliable, and efficient backup power that further lessens their daily dependence on the power grid.

Grid-tied solar electric systems are a great way to save money by using free power from the sun. However, for safety reasons, most grid-tied solar arrays are designed to shut down when they lose grid connection during a power outage. Solar storage bypasses this issue by storing excess solar power for later use, and acting as a backup if the connection is lost.

ReVision Energy’s two battery solutions, the Tesla Powerwall and the Generac PWRcell, enable you to access the free, abundant power of the sun, even during a grid failure. We have Tesla and Generac options available in Maine, New Hampshire, Massachusetts, and parts of Vermont. Additionally, ReVision Energy is both a Tesla Powerwall Certified Installer and a Generac PWRcell Certified Installer.

Batteries are covered by the 30% Federal Solar Tax Credit when combined with a solar installation. Starting in 2023, stand alone battery installations will be eligible for the tax credit as well. 


Most solar arrays are connected directly to the electricity grid, and any excess electricity produced by your solar panels that is not immediately needed by your home will export to the grid. You will receive credits for this excess power, and on days when your home needs more electricity than your solar panels are making, you’ll use those credits to draw power from the grid.

Adding a battery storage solution to your solar array reduces your dependence on the electric grid, and allows you to continue using solar energy even when the grid is down. Batteries work like laptop or cellphone batteries, storing power produced by your solar array for later use. This means that you have a fully charged battery ready to go, powering your house almost instantaneously when and if the grid goes down.

Checkout the video below for an overview of how solar storage works:


In addition to deciding between Tesla and Generac, your battery backup system will either back up the essential appliances or back up most of the house except for the heavy loads. You can work with your solar designer to decide what loads should be considered “protected loads” (usually refrigeration, water, some outlets) or create a list of which loads can be on the “non-protected list” (things like hot tubs, pool pumps, electric heating loads) since they would require a large number of batteries to back up.

Once you identify your home’s protected or non-protected list of loads, these devices will be connected to a sub-panel. If you decide on a protected load panel, those loads will be supplied by the battery and solar system during a grid failure. If it is a non-protected loads panel, those loads will be shed (not energized) during a grid failure.

Pairing solar electricity with battery storage is an excellent option for residential homes, whether you’re powering some loads in your home, interested in more independence from the grid, or simply looking for a cleaner, more efficient alternative to a traditional generator.


In New England, where ReVision Energy operates, we are no strangers to outages caused by harsh winter winds and unpredictable storms. Home standby generators tend to be the norm for backup power in utility outages. However, home batteries are becoming an increasingly attractive alternative.

Though generators may be cheaper initially, they are limited by their fuel dependence, maintenance, and service costs. While there are some limits to its power output capabilities, the battery pack generates no emissions, requires no recurring maintenance, and can be continuously charged by the sun.

Check out the comparative table below and see why a battery is a much more viable option than a generator:

 

  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
     

 

Leif-Heimbold-Powerwall-web.jpgWhile 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.


With the Powerwall you can store solar energy generated during the day for use at any time. During the day, the sun shines on your solar panels, charging your battery. At night, your home draws electricity from your battery, powering your home with clean, sustainable energy 24/7.

Installing a Powerwall with ReVision Energy is easy. We take care of everything from system design to permitting, installation, financing, and ongoing customer service.

4-tesla-powerwalls-installed-by-revision.jpgPowerwall consists of a 14 kWh lithium-ion battery pack, liquid thermal control system, an integrated inverter and software that intelligently dispatches electricity when it’s needed most. The unit mounts seamlessly on a wall or on the ground, and is connected to the grid to export excess energy, maximizing your opportunity for economic benefit.

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!”

Matt and Kate, who paired a Powerwall with their solar array at their 1870 farmhouse in Freeport, are also thrilled by their solar powered battery:

“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.”

Learn more about the Tesla Powerwall on their website or Download the Tesla Powerwall Brochure (PDF).



Revision Tesla Powerwall InstallerReVision 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.

Ready to start your solar storage journey? Get in touch with our Solar Advisors using the form below. 

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