A PV system in conjunction with batteries can provide security of supply in the case of grid power outages.
Example of a backup solar electric system providing security of supply for periods when the grid is off. Several configurations are possible, depending on requirements.
Systems can be configured to supply only priority loads when grid power is not available. This means that the battery bank can be smaller and/or have a longer service life. Some systems will also feed electricity into the grid while others will not. Careful system design and sizing, taking all factors into consideration, is required.
These solutions are especially interesting for critical facilities and for industrial/production processes that require a continuous energy supply.
Both lead-acid and lithium-ion batteries can be used. Lithium-ion batteries have much longer service lives than lead-acid batteries. Lead-acid batteries are cheaper to purchase but need to be replaced more often. The batteries and BESS (battery energy storage systems) market is undergoing major changes in terms of technological advances, efficiency improvements and cost reduction.