Solar panels on a glass roof

What to Look Out for When Purchasing Batteries for Your Solar Panels

For long, prospective customers of solar systems have wondered whether they will still get power if the grid goes down. And for long, our response has been a definite “no”, because grid-tied systems only work when the grid works.

Fortunately, in the past couple of years, there have been significant improvements in batteries, which makes them a viable option that can be installed along with solar systems. Before we get into choosing the best battery for your solar system, let’s consider the two main types of solar battery storage setups. This will help you figure out the right amount of energy storage capacity.

Off-Grid vs. Hybrid Systems

In an off-grid system, your property is not connected to the electricity grid in any way. All of your energy is generated by solar panels, or another backup generator if you so choose. This generated electricity is stored in batteries for use at night or during power outages.

In theory, with an off-grid system, your property becomes a self-sufficient island with no meters or energy bills. You will obviously need a lot of batteries to pull this off. But keep in mind that currently, this is not a long-term, economically viable option unless you’re living in a remote, rural area where just connecting to the distant grid will cost tens of thousands of dollars.

In the larger interest of providing custom solar solutions to our clients, we conducted a personal experiment to go totally off-grid. We lasted for just 33 days and 4 minutes. This seems to be a record for now and just goes to show what is possible with the technology as it stands right now. With future advancements in technology, we might expect to go completely off-grid forever.

In contrast to off-grid systems, hybrid systems are setups in which your property is connected to the electricity grid, but the system will prioritize the use of the stored electricity in your batteries over electricity from the grid. This is a lot cheaper because you won’t be paying the 17.62¢/kWh in New York State by buying it from the grid. Plus, you won’t be needing as much battery capacity either since some of it will come from the grid.

A hybrid system is the best option for the average household or SME. Simply put, adding around 13 kWh of high-quality lithium-ion batteries will add a decent amount of solar battery storage for use at night, keeping your reliance on the grid to a minimum. 

Choosing the Best Batteries

There’s a lot we can go over in terms of battery types and chemistry. But without going into unnecessary and confusing details, we can simply state that lithium ion batteries are the best options. You need to ensure that the battery comes from a manufacturer with a solid reputation and excellent reviews.

We’ve scoured all over for information on the best batteries to install in a solar system. And nothing comes close to the Tesla Powerwall 2 in terms of quality, safety, and reliability. The Powerwall 2 has a storage capacity of 13.5 kWh, which means that just one will do the trick, or two or three at most, depending on your specific solar system and your energy needs.

We hope you found useful our brief discussion on what to look out for when purchasing batteries for your solar panels. If you’re considering going solar, get a free quote from us. If you just want to learn more, get in touch with our friendly customer representative!