What happens to your solar when the power goes out?

The grid goes down. The sun is shining. Your panels are covered in light. And your house is still dark.

It is one of the most common surprises for new solar owners. You assume that because your panels make power, your lights will stay on. Then the first outage comes, and nothing works.

That is not a defect. It is how grid-tied solar is designed. Here is what is actually happening, and how to keep your power on next time.

Why grid-tied solar shuts off in an outage

Most solar systems in Hawaii are grid-tied. During normal operation, your panels power your home, and extra power flows back to the grid.

When the grid goes down, utility crews go to work repairing the lines. If your solar kept sending power onto those lines, it could injure the people fixing them. So grid-tied systems are required to shut off automatically the moment the grid drops.

It is not a malfunction. It is a safety feature, and it applies whether you have 10 panels or 40.

What a battery changes

A battery lets your home disconnect from the grid during an outage and run on its own. Your panels charge the battery during the day, and the battery powers your backed-up circuits day and night.

In other words, your home becomes its own small power island while the neighborhood waits for the grid to come back.

That is why we recommend every solar customer add a battery. Savings and backup depend on equipment, usage, utility rules, weather and stored charge. Off-grid operation requires a separate assessment.

What stays on, and for how long

Most batteries back up selected circuits, not your entire home. During setup, you choose what matters most.

One Tesla Powerwall 3 stores 13.5 kWh and adds about $13,000 to a new Independent Energy Hawaii solar system.

How to make your battery last longer

• Set your backup reserve to 100 percent following manufacturer instructions and permitted charging settings when a storm is forecast. Enable storm mode if your system supports it, and follow manufacturer instructions.

• Skip big loads like electric dryers, ovens and EV charging during an outage.

• Run larger appliances during the day, when your panels are recharging the battery.

• Check your app to see how much charge you have left and adjust.

Already have solar without a battery?

You do not need to start over. Batteries can be added to many existing systems after compatibility, electrical capacity and utility requirements are confirmed. Our team uses meters to make sure older panels work with the new battery before anything is installed.

Battery-only installs also qualify for a Participate Energy prepaid lease, which costs about 30 percent less upfront.

Key takeaways

• Grid-tied solar shuts off during an outage to protect utility crews.

• A battery lets your home keep running on its own while the grid is down.

• One Powerwall 3 runs essentials for about a day under modest essential loads, potentially longer with solar recharging. Runtime varies with loads, charge, weather and system design.

• Battery additions depend on equipment compatibility, electrical capacity and utility requirements.

Independent Energy Hawaii can help you assess battery options for selected-circuit backup during an outage.

We recommend every solar customer consider a battery for evening energy use and selected-circuit backup. Savings and runtime depend on system design, usage, utility rules, weather and stored charge. Solar without batteries remains available; off-grid operation requires a separate assessment.

A home battery does not guarantee uninterrupted medical support. Maintain a separate emergency plan for medical equipment.