When you consider the total ownership cost of solar panels – materials, installation, financing, and maintenance – they are now a cheaper electricity source than fossil fuels. However, since sunlight is not always available, solar panels cannot deliver power continuously. To use energy from the sun at night and on cloudy days, you need a solar battery.
via Sonnen USA
There are many types of energy storage systems, but batteries have many features that make them an ideal complement for solar panels. They are available in many sizes, ranging from compact home batteries to utility-scale systems that can power many buildings at once.
Just like you can install the ideal number of solar panels for your home, you can use a matching battery capacity that meets your energy needs.