Imagine you’re home on a stormy night, watching TV with the washing machine running, and all of a sudden the power goes out. Now imagine the same scenario, except you have a rooftop solar energy system with battery storage. When the power goes out in your neighborhood, you’d be blissfully unaware.  

A common myth about solar power is that you can count on it only when the sun is shining. You do need sunshine to generate electricity with solar, but what about the times when the sun isn’t shining? Most people rely on electricity from the power grid to supplement their solar-generated power. But residential solar energy system paired with battery storage—generally called solar-plus-storage systems—provide power regardless of the weather or the time of day without having to rely on backup power from the grid. 

Advantages of Combining Storage and Solar

1.Balancing electricity loads – Without storage, electricity must be generated and consumed at the same time, which may mean that grid operators take some generation offline, or “curtail” it, to avoid over-generation and grid reliability issues. Conversely, there may be other times, after sunset or on cloudy days, when there is little solar production but plenty of demand for power. Enter storage, which can be filled or charged when generation is high and power consumption is low, then dispensed when the load or demand is high. When some of the electricity produced by the sun is put into storage, that electricity can be used whenever grid operators need it, including after the sun has set. In this way, storage acts as an insurance policy for sunshine.

2.“Firming” solar generation – Short-term storage can ensure that quick changes in generation don’t greatly affect the output of a solar power plant. For example, a small battery can be used to ride through a brief generation disruption from a passing cloud, helping the grid maintain a “firm” electrical supply that is reliable and consistent.

3.Providing resilience – Solar and storage can provide backup power during an electrical disruption. They can keep critical facilities operating to ensure continuous essential services, like communications. Solar panel and storage can also be used for microgrids and smaller-scale applications, like mobile or portable power units.