How to Use Solar Panels During Power Outage

Power outages can happen unexpectedly due to hurricanes, grid failures, or maintenance.

In such situations, a common question is: Do solar panels work during a power outage? Of course, they can continue to produce electricity as long as there is sunlight, theoretically.

However, the reality is more complicated. While solar panels can generate power during an outage, whether that energy reaches your home depends entirely on your system’s design.

This guide explains why solar panels may stop working during outages and provides actionable solutions to keep your home powered.

Can solar panels power a house during power outage

During a power outage, as long as there is sunlight, solar panels can still generate electricity and supply power to your home as usual. There are only two situations in which the solar array will stop powering your house:

1. Typical grid tie solar system

First, grid-tied systems with standard inverters require an active connection to the utility grid to function. Under normal conditions, the solar panels generate electricity to power household loads, and any excess energy is sent back to the grid.

When a power outage occurs, the grid-tied inverter loses the necessary grid voltage to operate. As a result, the connection breaks, and the entire system automatically shuts down. It will only resume operation once the grid is restored.

This shutdown is a safety requirement mandated by regulations such as UL 1741 and IEEE 1547, to prevent solar electricity from feeding back into the grid, which could endanger utility workers performing repairs.

2. Off grid solar system without energy storage

If your system doesn't include an energy storage solution, you'll find that your solar panels still won’t be able to power your home during a blackout.

These systems without batteries face another key limitation: even if the solar system could technically operate during an outage, weak or inconsistent sunlight means the panels produce only a small amount of current, usually not enough to power your home continuously or meet energy demands. This is especially true if the original system was designed only to offset part of your electricity bill.

How to use solar panels during power outage

If you want to use solar panel to survive a power outage, here we offer 4 solutions:

Add solar batteries for backup

Add a solar battery to the existing system is one of the most effective ways to maintain energy independence. A battery acts as a buffer, storing energy to balance supply and demand. By designing a backup system based on your household’s energy consumption, you ensure stable power, whether your solar panels generate more or less than what you need during an outage.

For off grid system, if your inverter includes a battery charging port, adding a battery backup is straightforward.

However, most standard grid-tied inverters shut down during a power outage due to safety regulations, which means your solar panels won’t power your home when the grid is down. To add battery backup to an existing solar system, you need either an AC-coupled or DC-coupled solution that includes both an inverter and a battery.

• AC coupling system requires a compatible inverter that supports AC coupling, often with strict requirements for inverter models, firmware, and battery sizing. This can make AC coupling more expensive and complex to implement.
• Placing a charge controller with high voltage transfer switch between the solar array and the existing grid tie inverter, such as Morningstar TR version, is a developed option for DC coupling, which allow you to manually switch to a off grid backup system, using the solar energy during power outage.

Integrate a generator with your solar system

Pairing a generator with your solar setup is a economical way to ensure reliable backup power during outages. Generators can supply energy at night or during cloudy weather when solar production drops.

For off-grid setups, the integration is often more straightforward. If your inverter supports generator input, you can add the generator to the inverter’s AC input. When the generator is running, the inverter treats it as an AC power source, similar to grid input. This helps recharge the batteries and prevents over-discharge.

To simplify the process further, you can choose an inverter with a dedicated generator input port, such as the POW-HVM6.2K-PRO. This eliminates the need for emergency rewiring or manual switching during an outage, allowing for faster, safer integration.

The power supplied by the generator can be used to run household loads. This is especially valuable for maintaining power overnight or during extended periods of poor solar production.

In a grid-tied system, integrating a generator depends on the type of inverter you have. Most standard grid-tied inverters are not designed to accept generator input directly. To make it work, you typically need an automatic transfer switch (ATS) that can isolate your home from the grid and allow generator input during outages. In this setup, when the grid fails, the ATS disconnects the grid and automatically switches the power source to the generator, enabling your system to keep running safely.

Importantly, the grid-tied inverter and the generator should not be connected to the same output circuits. Instead, use a critical load sub-panel for the genergator to isolate essential backup circuits.

Prioritize critical loads during an outage

Some inverters feature two AC output ports: a main output and a secondary output designed for power outages. By setting a battery voltage cutoff for the secondary output, you can optimize energy distribution during emergencies.

For example, you might choose to keep essential devices like lights, refrigerators, internet routers, and medical equipment powered, while excluding heavy loads such as electric heaters or EV chargers during an outage.

This approach ensures that even with limited battery capacity, you avoid unnecessary investment in oversized storage while extending backup time for critical loads, rather than draining the battery too quickly at the start of a blackout.

Upgrade to an energy-storage-ready inverter (grid-tie system)

If you're using a grid-tied inverter without battery support, consider upgrading to a grid tie hybrid inverter like SOLXPOW. These inverters can manage solar panels, batteries, and grid power while feeding excess energy back to the grid.

Unlike standard grid-tied systems, hybrid inverters automatically prevent backfeeding during outages, redirecting solar energy to power your home, keeping it simple, safe, and more efficient than AC coupling or DC coupling.

Conclusion

Using solar panels during a power outage is straightforward—if your system is properly designed for backup. For grid-tied systems, the main challenge is meeting local safety regulations. Always consult a licensed installer familiar with your region’s requirements before retrofitting your solar power system.