Does Home Solar Work in a Blackout?

Home Solar and Battery in a Blackout

Most of us associate electricity blackouts with storms. Hurricanes, earthquakes, or severe thunderstorms can cause significant damage to powerlines. In July 2019, over 250,000 JCP&L customers lost power due to severe thunderstorms - many homes were in the dark for several days.1

But blackouts can also be caused by overloading our power grid - too many people using too much power at once. In 2019, hot weather caused power outages in New York2 and calls for electricity conservation across Texas.3

In addition, California is experiencing utility-mandated power outages due to wildfire weather conditions. In October 2019, nearly 800,000 PG&E customers had their life interrupted by a public safety power shutoff.4

Will My Home Solar System Work in a Power Outage?

If you have a grid-tied home solar system without a battery, your home solar system will not work during a grid outage. You will not be able to produce or consume solar energy while the grid is down.

When the grid goes down, your home solar system will automatically turn off. This is to prevent solar energy flowing through the utility grid while repair crews fix any downed power lines or other failures. When the grid comes back up, your home solar system will automatically turn back on.

Backup Energy with Solar Battery Storage

Home Solar With Battery in Blackout

During a grid outage, a home solar system with a battery can function as a nanogrid.5

When the grid is down:

  • A battery can power your essential lights and appliances.1 When your battery is installed, you may be asked to choose “critical energy loads” that are most important to power during a grid outage. Your battery will be connected to the critical loads.
  • Your solar panels can keep generating power from the sun.1 There is no risk of sending excess solar production to the grid since excess solar production will charge the battery.

The amount of backup power available will depend on your battery configuration.

Self-Consumption

Backup Power

Time of Use Optimization

The battery minimum reserve is set to 20% of its capacity during normal operation.6 If the grid goes down, your most needed lights and appliances will be powered by your battery.

During extended power outages, your home solar system will work to provide energy to your home and to recharge your battery. The battery may not fully recharge depending on your solar production.

The battery will maintain full charge capacity during normal operation. If the grid goes down, your most needed lights and appliances will be powered by your battery.

During extended power outages, your home solar system will work to provide energy to your home and to recharge your battery. The battery may not fully recharge depending on your solar production.

The battery minimum reserve is set to 20% of its capacity during normal operation.6 If the grid goes down, your most needed lights and appliances will be powered by your battery.

During extended power outages, your home solar system will work to provide energy to your home and to recharge your battery. The battery may not fully recharge depending on your solar production.

Read more about TOU configuration here.

 

Learn More About Solar Battery Storage

Interested in battery storage? Sunnova has options:

 You may be eligible for incentives that can help with the cost of the battery!7

To learn more about going solar or adding storage with Sunnova, let us know how to get in touch!

 

1. JCP&L
2. conEdison
3. ERCOT
4. PG&E
5. The amount of power available from the battery during a power outage is limited, depending on the loads connected, customer usage and battery configuration (i.e. batteries in certain areas may be set up to provide you with the best economic benefit, which may affect the amount of back-up power available). Solar systems and/or batteries may require repairs after weather events and such repairs may be delayed due to forces outside of our control. No assurances can be given that the solar system or the battery will always work. You should never rely upon either of these to power life support or other medical devices.
6. You will have the option to change the minimum battery reserve. Sunnova recommends a 20% minimum reserve.
7. You may be eligible for a federal Investment Tax Credit (ITC) with the purchase of a solar system. To receive the full federal tax credit, you must have federal income tax liability at least equal to the value of the tax credit. Additional tax credits may also be available for homeowners in certain states and territories. Sunnova makes no guarantees regarding customer eligibility for tax benefits. Sunnova does not provide tax advice. Contact your personal tax advisor for eligibility requirements. All state and utility incentives are subject to state funding and legislation.