Here’s why: Going off-grid requires energy storage (a lot of it) An off-grid solar system can be a solid way to power a shed or a portion of your home, but it rarely makes practical and financial sense for a whole home, even with energy storage. On average, you’ll need around 12 solar batteries to go off the grid.
As with grid-tied systems, you can increase the efficiency of off-grid solar by expanding output and battery capacity as your energy needs grow. The cost of going solar has fallen significantly in recent years. Supply and installation of a 4kW system, for example, typically costs around £9,500.
Cost: Off-grid solar PV systems can be more expensive to install than grid-connected solar PV systems due to the need for energy storage batteries, charge controllers, and other components. The cost of batteries has been declining in recent years, but it remains a significant portion of the overall system cost .
Without battery storage, off-grid solar PV systems would only be able to provide electricity during the day, which may not meet the energy demand of the user [19, 20]. Moreover, battery storage can help reduce the size and cost of off-grid solar PV systems by reducing the need for larger solar panels or backup generators.
However, there are also some limitations to these systems, including: Limited Energy Storage Capacity: The energy storage capacity of batteries used in off-grid solar PV systems is limited, which means that these systems cannot generate electricity continuously over an extended period.
Existing markets for storage systems in off-grid applications Electrochemical Energy Storage for Renewable Sources and Grid Balancing, Elsevier, New York ( 2015) Global Markets. Chapter in Solar Energy Markets: An Analysis of the Global Solar Industry