On a stormy night, a tree falls on a nearby power line and you watch as the houses on your street go dark. Your lights go out for a moment and then quickly come back on. Your home continues to buzz with the sounds of the TV, the dishwasher and your refrigerator. In the garage, your energy storage device has noted the outage on the grid and shifted into power delivery mode. This protects your home from the power outage.
This scene shows the power of battery storage and how it works. While unplanned outages don’t occur often in Santa Clara, storage can be a useful tool for residents with outage‑sensitive needs, such as medical devices. Storage also helps residents avoid being inconvenienced by an outage.
Battery storage is a type of energy storage system that pairs a lithium‑ion battery (with or without rooftop solar panels) to store energy in your home for later use. Storage devices charge when excess energy is produced. The battery releases the energy when it is desired or most needed, such as during an outage. The stored power can be used as a backup to help lessen outage effects.
While energy storage can be used for vital backup during an outage, the stored energy can also be used for everyday needs. Residents may choose to use stored power during the evening to increase solar power usage and reduce energy drawn from the grid.
Residents with energy storage still remain tied to the electric grid for regular service. Stored energy can power the home during an emergency if the battery is charged, but the grid provides power when there isn’t enough energy stored in the battery. For instance, powering appliances such as air conditioners may require more energy than the battery can deliver.
According to a McKinsey report on battery storage, prices have fallen over 77 percent since 2010. However, the benefits can offset the costs in some cases. Today, storage systems can save customers money if they live in an area with high electricity costs and plenty of sun. Given our low electricity rates, the use of battery storage in Santa Clara may be driven by interest in the technology or by using storage to boost usage of solar power from your rooftop.