The main difference between off-grid and on-grid solutions is that an off-grid system is not connected to the electrical grid, whereas an on-grid system is connected to the grid. Off-grid systems must rely on batteries to store the energy they generate, whereas on-grid systems can feed excess energy back into the grid. Additionally, off-grid systems are more expensive to install, as they require batteries and other equipment, whereas on-grid systems are cheaper and simpler. Finally, on-grid systems will lose power when the grid loses power, whereas off-grid systems are independent of the grid and will remain functioning even during a power outage.