Sometimes two are better than one. Combining solar and storage technologies is one such case. Why: Solar energy isn't always generated when it's needed most. Peak electricity usage typically occurs in summer afternoons and evenings, when solar power production is declining. During this time, temperatures can peak and people who work during the day come home and start using electricity to cool their homes, cook meals and run appliances.

Storage helps solar energy contribute to electricity supply even when there is no sunlight. It could also help smooth out changes in how solar energy flows on the grid. These changes are attributed to changes in the amount of sunlight hitting photovoltaic (PV) panels or concentrating solar thermal (CSP) systems. Solar energy production can be affected by obstacles such as seasons, time of day, clouds, dust, haze or shade, rain, snow and mud. Sometimes energy storage is co-located with or adjacent to the solar system, and sometimes the energy storage system is stand-alone, but in either configuration it can help integrate solar energy into the energy landscape more efficiently.

What is energy storage?
"Storage" refers to technologies that capture electricity, store it as another form of energy (chemical, thermal, mechanical), and then release it for use when needed. Lithium-ion batteries are one such technology. While using energy storage is never 100% efficient - some energy is always lost during energy conversion and recovery - storage allows for flexible use of energy at different times when it is produced. Therefore, storage can improve system efficiency and resiliency, and can improve power quality by matching supply and demand.

Energy storage facilities distinguish between energy capacity, the total amount of energy that can be stored (usually measured in kilowatt-hours or megawatt-hours), and power capacity, the total amount of energy that can be released at a given time. Usually measured in kilowatts or megawatts). Different energy and power capacities stored can be used to manage different tasks. Short-term storage, lasting only a few minutes, will ensure that solar power plants operate smoothly during output fluctuations caused by cloud transmission, while long-term storage can help provide days or weeks of supply during periods of low solar production or major weather events.