Hurricane Ian The power grid is down can solar and batteries be able to power your home?

Hurricane Ian’s destructive winds and floods are expected to bring long-lasting power outages to large portions of Florida. The hurricane will be the latest storm in a line of hurricanes and extreme temperature and cold conditions that have knocked out power to millions Americans in recent years for days at a time.

In numerous outage and disaster-prone areas, people are starting to ask whether the investment in solar rooftops and battery storage systems will keep the lights on and the air conditioner on even when the power grid isn’t.

If the grid is down the majority of solar systems that lack a battery will also be shut down. However, with batteries, homes can be disconnected to the grid. Every day, the sun lights the home and recharges the batteries, which supply electricity throughout the night.

Our group at Berkeley Lab examined what it would be like for homes and commercial buildings to ride out lengthy power outages of three or more days, with solar and batteries.

How much can solar + storage do?

In an new report we have created the typical power outage that affects each county within the U.S., testing whether rooftop solar systems with a 10 or 30-kilowatt-hour battery is able to provide power to critical loads such as lighting, refrigeration Internet service, and pumps; should it be able to extend the power as well as power cooling and heating or, if it is able to power a whole home.

For a better understanding The most well-known battery in the market is the Tesla Powerwall, has just over 13 kWh of capacity.

In general, we found that even a modest system of solar and one battery could power vital appliances in a house for days at a stretch virtually anywhere in the country.

However, our maps demonstrate that providing backup power for heating and cooling can be difficult, but it’s not an impossible one. The homes located in the Southeast and Pacific Northwest often have power-hogging electric resistance heaters, exceeding the capabilities of solar as well as storage during winter outages. The homes that have efficient heat pumps did better. The summer load of air conditioning can be a lot in the Southwest which makes it difficult to meet all cooling needs through storage and solar power in the event of a blackout in summer.

Larger solar and battery systems can assist, but the ability to meet demand during power outages is dependent on the weather, how energy efficient the home is, as well as other elements. For instance, simple adjustments to the thermostat during power outages reduce the demand for cooling and heating, and let solar storage keep backup power for longer periods.

Solar and storage using batteries of 10 kWh can provide backup powerin a variety of situations. Berkeley Lab, CC BY

The power source for commercial buildings differs according to the type of building. Retail stores and schools with enough roof space to allow solar power relative to building power demand are much more efficient than multistory, energy-intensive buildings such as hospitals.

What would solar have done in the event of 10 disasters in the past?

We also looked at 10 real-world events that caused outages from 2017 to 2020, such as hurricanes, wildfires and storms, and modeled building performance for specific locations and real weather patterns before and after the outages.

We discovered that during seven of the outages, most homes would have been capable of sustaining essential loads, as well as heating and cooling by using solar with 30 kWh of storage, or about two Powerwalls.

But the weather around the power outage could make a huge difference, especially for hurricanes. In the aftermath of Florence, the most powerful hurricane in history Florence knocked out power throughout North Carolina in 2018, cloudy skies hung around for three days, dimming or stopping the solar panel’s output.

The hurricane Harvey, on the other hand, struck the Texas coast in August 2017 but moved ahead to cause extensive damage elsewhere in Texas. Over Corpus Christi cleared even as it took a longer or more time to restore power. Storage and solar power would have been a big help in that case as they could provide all the electrical needs of a typical single-family home, after it cleared.

What a typical house would have fared with solar power along with 30 kWh storage following hurricanes Florence and Harvey. The light blue line shows the short periods of ‘unserved load,’ or gaps in the ability to meet demand for power following the storms. The charge state shows batteries were able stretch solar power through the night.  

FIND SOLAR SYSTEMS/BACKUP FOR YOUR HOME

Similar to solar, we have found that solar can do well when the weather is less cloudy such as wildfire prevention shutoffs in California or following the 2020 derecho windstorm in Iowa.

The source of heat in a home is also an important aspect. In a period of five to 10 days following an snowstorm in Oklahoma in 2020, we found that solar plus a 30-kWh battery could have provided nearly all the vital power and warmth required by homes equipped with the natural gas heating system or heat pump. However, homes equipped with electric resistance heating would have fallen short.

In Texas more than half the homes in Texas are heated by electricity mostly resistance heaters. Heat pumps that are Energy Star-certified – which offer heating and cooling – consume only half the amount of power in terms of output heat as resistance heating units and can also be more efficient in cooling than the standard air conditioning unit. Converting old resistance heaters to new heat pumps can not only save money and reduce peak demand but also increase the resilience of your system during outages.

New backup forms

Setting up solar and storage systems to supply backup power in the building or home takes extra work and it costs more. One Powerwall could cost from US$12,000 to $15,500 for a complete installation, before tax incentives or other. That’s as much as an adequate solar system. But, a growing percentage people are installing these.

Over 90 percent of solar projects that were built located in Hawaii in 2021 were paired with batteries after a regulation change. The distributed power plants are aiding in the power grid in the event that coal plants are decommissioned.

California has over 1.5 million rooftop solar panels. An increasing number of consumers are retrofitting batteries to system, and adding new solar and storage systems, in part because utilities have resorted to “public safety power shutoffs” to limit the possibility of wildfires caused by power lines on the dry, windy weather.

Electric cars and trucks contain more battery storage than the Powerwall and could be used as the future home batteries. Ford

As well, new types for backup power is emerging from electric cars, particularly. Ford is partnering with SunRun to integrate its brand new F150 Lightning electric pickup truck with solar and a two-way charger that could utilize the battery of the truck to power a home. The base model of this truck is equipped with a one 98-kWh battery. That’s the equivalent of seven Tesla Powerwall stationary batteries.

Critical power for critical services

A fire station in Puerto Rico offers a glimpse of what storage and solar can accomplish. After Hurricane Maria interrupted power for a period of time during 2017, over 40000 solar panels were set up throughout the island, usually combined with battery storage. One of these is in the fire station of Guanica, the town. Guanica which was not able to handle emergencies during previous outages.

After Hurricane Fiona’s winds and flooding again knocked out electricity to the majority areas of Puerto Rico in September 2022, the fire station was still in operation.

“The solar system is working beautifully!” Sgt. Luis Saez told Canary Media the following day that Fiona knocked out power. “We did not lose power all throughout the hurricane.”

 

 

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