Solar and batteries can help power your home during hurricane season

Summer is here, and with it comes storm season.

If you’re considering going solar, you may have questions about how your system will work during power outages caused by strong summer storms—even hurricanes. Solar homeowners who have weathered past storms know the answer: Solar when paired with battery storage can help you and your family home weather the next storm. Batteries allow you to store the electricity you generate from your solar panel and ensure you have electricity when the grid goes down.

More than 75,000 homes and businesses across Puerto Rico have already installed solar-plus-battery projects to avoid the routine outages, damaging voltage surges and soaring electricity prices that plague the centralized system. Battery storage keeps your essential appliances up and running when you need them most. You won’t be able to run everything but you’ll be able to keep the lights on, charge your phone to stay in contact with your loved ones, keep the fridge on to keep food from spoiling, and even use the backup power to keep medical equipment running. 

“During Hurricane Fiona, I was able to use the energy stored from my batteries that I generated from my rooftop solar system to get electricity, when the rest of the neighborhood couldn’t. I learned that it was important to prepare for the storm in advance and to make a plan to maximize my battery capacity in the event of a power outage lasting several days. The cloudy days after the storm partially reduced my solar energy production so I needed to recharge my batteries. This is why it is important to save your stored energy for critical needs, such as lights, refrigerator and fans.The laundry should be done well ahead of time! Overall, the system performed great and I was able to keep my family safe and secure after the storm.”

—Daniel Muñoz, resident of San Juan and member of the University Gardens 2020 Solar Co-op

How does battery storage work?

Most homeowners who use battery storage do so for the backup power it provides during grid outages. When your utility grid goes down and you lose electric service, you can use a battery system to power some or all of your household electricity needs (called “loads”).  

Battery backup systems work by isolating some or all of your essential loads from the main utility system with something called an “automatic transfer switch”. Batteries then power those loads with electricity stored in the battery bank. The backed-up loads in your home then automatically reconnect to the grid when the utility grid power returns. The result is that these “essential ” loads receive power even when the grid is down, switching seamlessly between utility electricity and stored electricity from your battery. When it comes to considering batteries, folks should ask themselves “What do I need to power and for how long”? Essential loads usually consist of fans, refrigerators, communication devices, etc. Essential loads are considered to be things that one cannot live without. When looking into batteries, factors such as size, price, technology, warranties and ability to be used with a generator are all varying factors to keep in mind and tailor to your needs. Warranties for batteries depend on the type of battery technology and usage. Be sure to read the fine print, some battery warranties may not cover certain types of usage scenarios, may dictate that batteries be kept under certain conditions (inside).

The importance of battery management after the storm

It’s important that during and after a storm, solar system owners try to reduce their energy consumption in their homes. Storm conditions could last for several days potentially impacting your ability to harness the power of the sun’s rays and generate the energy needed  to recharge your battery. This is why you’ll want to conserve your energy usage and make sure you have enough power for the essentials. This might include lights, fans, refrigerator, or medical equipment. Management of your electricity consumption in your home will help you get through the storm and maximize your stored energy.

Not all batteries are equal. Homeowners should check with their installer before jump starting batteries.  In some cases, jump starting a battery may be necessary  when the weather conditions don’t allow the sun to recharge it when the electric grid is down. Some batteries will not charge from solar when at near zero capacity after being discharged. This requires a ‘jump start’  Homeowners should exercise extreme caution and not jump start their batteries on their own. Not all batteries could be jump started with a generator. This is unsafe and severe damage to your solar and battery system could occur. It is essential that you communicate with your installer first to find out if your battery can handle a jump start and if so, how to safely go about it. 

How solar owner can prepare for the next storm 

Regardless of the projected magnitude of any storm, preparation is key. Solar homeowners should:

• Clear site of any debris, loose material, or equipment no longer in use.
• Cut back vegetation or tree branches that could cause damage to the system.
• Check your system monitoring software and confirm the system is working properly. 
• Make sure you know how to read how much energy is in your battery directly from your equipment on site. During outages you may not have internet access. Reading this information from your onsite equipment will help you manage your home electricity usage while the power is out so you have enough energy to last. 
• Have your contact information for your installer ready in case you have questions or need assistance.
• Use solar powered lanterns to provide light at night to help reduce your energy usage