Step-1: It works as both the off-grid and on-grid systems – during the day when the sun is shining brightly, the panels convert the rays to electricity and any excess will be stored in the batteries, much like the off-grid systems. However, if even after storing in batteries and using electricity in your home, there is still excess power, the system then sends this excess back to the grid according to the rate of the chosen feed in tariff, similar to the on-grid system.
Step-2: Since the batteries are continually charged during the day, they are able to store enough energy. During times of outages and little or no sunshine, the home can draw its power from these batteries. If however, these adverse situations last for too long, the batteries can be recharged from the grid and your home will only use as much power from the grid as is required to recharge the batteries.
Step-3: Till the batteries are recharged or the grid begins to function as usual, your home will still have an uninterrupted power supply since it will draw power from the grid. This keeps the cost of power down.