Do Solar Panels Work During a Power Outage?

When severe weather strikes and causes widespread power outages, many homeowners wonder if their solar panel systems will still provide power to certain circuits in their homes. The short answer is that solar panels can and do continue generating electricity during an outage under the right circumstances. In this article, we’ll explore in more detail how solar power systems function when the main utility grid goes down.

How Solar Panels Produce Power

Before delving into how solar performs during outages, it helps to review the basic process of how photovoltaic (PV) solar panels generate electricity from sunlight. PV cells convert sunlight directly into direct-current (DC) electricity. Several cells are combined into modules, and multiple modules make up an entire solar array installed on your roof.

An important component called an inverter is needed to convert the DC power from the solar array into alternating current (AC) electricity that can power standard household appliances. The inverter interconnects the solar system to your home’s main electrical panel. As long as the sun is shining on clear solar panels, they will produce DC power that can be inverted to AC.

How Solar Functions in an Outage

During normal daytime operation when utility power is available, your solar panels will generate electricity from the sun. The solar inverter converts this to AC and either uses the power in your home directly or sends excess generation back to the grid through net metering.

If the main power goes out, several possibilities exist for how your solar system will function, depending on how it was installed:

• Standalone (Off-Grid) Systems – An inverter, batteries, and a transfer switch allow these systems to power selected home circuits independent of the grid during outages. Batteries store solar energy for the night too.
• Grid-Tied w/Backup Power – An upgraded inverter and transfer switch let solar provide backup electricity for some appliances and outlets if utility power is lost. Needs daylight to function.
• Simple Grid-Tied – No battery storage or transfer capabilities. When the grid loses power, the solar system automatically shuts down for safety since it’s still connected to the larger grid. Provides no outage backup.

For solar to work independently during blackouts, battery storage is essential for storing daytime solar production for cloudy, rainy or nighttime use. A transfer mechanism is also needed to disconnect from the grid in emergencies.

Components Needed for Off-Grid Solar Backup

To summarize the key components required for a solar energy system to function reliably as a backup power source during outages:

• Solar Panel – High-quality PV panels to convert sunlight to DC electricity during daytime hours.
• Solar Inverter – Special inverter that can function independently of or in parallel with the utility grid.
• Battery Bank – Deep-cycle batteries like lithium-ion to store excess solar energy for nighttime and cloudy conditions.
• Monitoring System – Displays system performance and battery levels in real-time for the homeowner.
• Automatic Transfer Switch – Senses loss of grid power and switches solar system over to battery backup mode.

Properly sized and high-quality components are important to ensure a solar battery backup system delivers on its promise to keep critical circuits operational day and night during prolonged power interruptions. Professional solar companies can properly assess your home’s needs and design a suitable off-grid/backup system.

What Circuits Can Solar Power Use in an Outage?

Even with the proper independent or standby system configuration, solar storage can’t realistically power an entire home indefinitely. However, it can keep essentials online. Typical circuits continued by solar in an outage include:

• Lights – LED bulbs drain little energy so lights stay functional for visibility and safety.
• Refrigerators – critical to preventing food spoilage in a power blackout lasting over 4 hours without power.
• Electronics – Devices can be recharged to power phones, and tablets for emergency communications.
• Well Pump – Provides access to fresh water for basic needs if you have a well water system.
• Sump Pump: Helps prevent basement flooding during rainy outages, which is critical to some homes.

By prioritizing the most essential appliances and identifying circuits with minimal loads, solar backup adequately supports a family until main power is restored. It’s not a whole-home solution but enables basic necessities.

Is a Solar Backup System Worth It?

For homeowners concerned about the reliability of utility power or in areas prone to frequent outages, a solar battery backup system offers peace of mind. While an initial investment, the value is difficult to place on essential power supporting your family’s basic needs in an emergency. However, some factors to consider include:

• Outage frequency in your region and the likelihood that your system would get meaningful use—at least several days per year of usefulness—typically merits the cost.
• Upfront installation expense compared to your budget, tax incentives, and your electric bill cost savings over time from self-generated solar power
• Life of system components like long-lasting lithium batteries versus maintenance and eventual replacement costs factored over a 15-25+ year lifespan.
• Personal priorities revolve around self-reliance, cutting utility bills and dependence long-term, and resilience during natural disasters or infrastructure disruptions.

On balance, solar battery backup often proves a worthwhile investment for homeowners highly concerned about utility reliability or preparedness for weather emergencies by keeping essentials running independently of the main power grid when needed most. Talking to a reputable local installer can help you decide if it fits your situation.