What Happens to My Solar Power When the Grid is Down?

Battery Charging and Grid Disconnection

When the grid goes down, your solar panels will continue to generate electricity and charge your battery backup system. This is because solar panels do not require a grid connection to operate, and most battery backup systems, like the Powerwall or Enphase EG4, have an automatic transfer switch (ATS) that disconnects the grid power source and connects the battery backup system when the grid is down. This ensures that your solar power is directed to the battery, where it can be stored and used to power your critical loads.

Critical Loads and Automatic Transfer

To ensure that your critical loads, such as lights, refrigerators, and medical equipment, remain powered during a grid outage, you’ll need to configure your automatic transfer switch (ATS) to prioritize these loads. This is typically done by identifying the critical loads and assigning them a higher priority in the ATS settings. For example, in the Enphase EG4 system, you can configure the ATS to automatically transfer power to critical loads like lights, refrigerators, and medical equipment, while disconnecting non-essential loads like air conditioning and pool pumps.

System Configuration and Monitoring

To ensure that your solar power system is functioning correctly and automatically transferring power to your critical loads during a grid outage, it’s essential to properly configure and monitor your system. This includes configuring the ATS settings, monitoring battery state of charge, and verifying that the system is automatically transferring power to critical loads when the grid goes down. Regular maintenance and inspections can also help ensure that your system is functioning correctly and that any issues are quickly identified and addressed.