Solar Battery Capacity And Performance – More and more American homes are pairing rooftop solar with a solar battery system. With utility rates constantly on the rise, storing solar power for nighttime use has become a smart investment for many households. Homeowners are also looking for blackout protection in the face of extreme weather and wildfire-related power shutdowns, especially in California.
If you’re one of those homeowners looking to add a home battery system to your solar installation, here are five things you should know:
Not all battery chemistry is the same
Most home solar storage systems use a lithium ion battery, the kind used in smartphones and electric cars. The problem with lithium ion is that it’s prone to thermal runaway, in which the battery rapidly overheats and combusts, potentially releasing toxic cobalt.
The importance of capacity and power
Solar batteries come with all kinds of specifications, but these are the two most important performance indicators. Capacity is the total amount of energy a battery can store, measured in kilowatt-hours (KWh). Power indicates how much inverting power the energy storage system has.
Think of this like speed. High capacity combined with high power means the system can power more appliances for a longer time.
Whole-home backup protection is not possible for very long
No residential storage system on the market has enough power and storage capacity to run an entire home, regardless of their advertising. Think of it like this: A 5,000-watt inverter will afford the home 5,000 watts of energy use, or approximately 20.83 Amps of power. So, a larger, more powerful inverter can power more of the home.
Most homes use between 20 and 60 amps or more of power per hour. High-amperage appliances like air conditioning, electric ovens, and electric water heaters use massive amounts of power when running, so whole-home backup is not realistic with today’s battery and inverter technology.
What the right system can do is keep your lights and your critical appliances on long enough to get you through a blackout and have your solar panels recharge your battery the next day. Again, look at the ratings for capacity and power when comparing systems.
The balance between Time of Use optimizing and resiliency
When choosing a home solar battery, you want a system that can reduce utility costs by powering the home after sunset, when utility rates are highest, and provide power when a grid outage occurs.
Balancing both needs is not as easy as it sounds. If a battery is powering an appliance that uses a high amount of electricity such as an air conditioner, the battery can drain quickly, leaving nothing left for a grid outage.