Home energy storage has featured frequently in the news over the past few months thanks to new battery products from companies like Tesla, LG and Mercedes-Benz. These products are popular for a reason: when you pair solar panels with a battery bank at your home or business, you can actually operate independently from the electric grid. However, not all solar batteries are created equal. Here’s the rundown on what it actually takes to use a solar panel battery bank to go off the grid.
Can you use a solar battery bank to “cut the cord” with your electric utility?
Most solar energy system don’t have batteries – instead, rooftop or ground-mounted solar panels are usually connected to the electric grid. This makes it possible for you to feed excess electricity back into the grid, and to draw electricity when your solar panels aren’t producing enough energy. If you don’t want to be grid-tied, you need to install a bank of solar batteries with your solar panels.
However, not every home is suited to an off-grid solar battery bank. For most homeowners in the U.S., the amount of solar electricity your system will produce from month to month is going to vary as a result of seasonal differences in sunlight. Maintaining a connection to the grid ensures that when your solar panels under-produce in the winter you can still keep the lights on.
If you do want to make the jump to an off-grid solar panel battery bank system, you’ll need more than just a Tesla Powerwall. Most of the home energy storage products that have been in the news lately aren’t designed for completely off-grid use. Rather, they are designed to help you reduce the amount of energy you send back to the electric grid, and can provide a few hours of backup power in the event of a power outage. A solar panel battery bank that can take you off-grid will be bigger (and much more expensive) than a Tesla Powerwall or an LG Chem RESU.
To have a cost-effective solar panel battery bank installation, your first step needs to be reducing your daily electricity use. Weatherizing and insulating your home, upgrading to energy efficient appliances, and installing a smart thermostat are just a few of the steps that you can take towards an energy-efficient home.
You can also proactively install an energy monitor to get an idea of which appliances (or personal habits) are resulting in the highest electricity use in your home. Once you have worked to reduce your electricity consumption, you can start the process of shopping for a home solar panel battery bank.
What size solar panel battery bank do you need for your home?
The size of your solar panel battery bank is calculated with the answers to two key questions:
- What is your daily energy consumption?
- How many “days of autonomy” do you need?
Daily energy consumption
If you plan on going off the grid, you’ll want a solar panel battery bank that can supply enough electricity for your home to operate without any issues, so you need to know how much energy you use on a day-to-day basis. The less you consume, the more feasible it will be to install a solar panel battery bank.
This is where an energy monitor comes in handy, but if you don’t have one, you can look at your utility electric bill and make an estimate based on your total monthly consumption.
“Days of autonomy”
Your solar panels won’t always produce electricity – cloudy or rainy days can significantly reduce your daily electricity output. On top of that, while your panels will only generate electricity for a few hours of the day, your home uses electricity constantly, even when you’re sleeping.
You need to decide how many days of electricity you want to have stored up so that your home has power even when your panels aren’t generating energy. Most homes with solar battery banks aim for three to five days of autonomy.
Work with a solar-plus-storage installer to design your solar panel battery bank
Armed with your daily energy consumption, and your desired number of “days of autonomy,” a solar-plus-storage installer can help you design a system that suits your needs.
Even if you decide not to go completely off the grid, solar panels are still a strong investment, and solar battery technology is becoming cheaper every year. With $0-down solar loans and solar leases, you can save money on your electricity bills as soon as your solar system is up and running, and you may even be able to get rebates or production-based incentives for switching to solar energy.
To learn more, use a solar calculator to get an instant estimate of what solar can do for your home. And as with any other major purchase, be sure to comparison shop for solar equipment and financing options before selecting the ultimate installer you plan to use.