Solar Battery Backup Capacity Calculator

DoD represents the percentage of battery capacity that can be safely used without causing cell damage. Lead-acid batteries should not exceed 50% DoD, while lithium-ion batteries can safely run up to 80-90% DoD.

The central government provides a direct subsidy of Rs. 30,000 per kW for the first 2 kW of solar capacity, and Rs. 18,000 for the 3rd kW. The maximum subsidy is capped at Rs. 78,000 for any residential installation of 3 kW or higher.

A 3 kW residential solar system requires approximately 250 to 300 square feet of shadow-free rooftop space. Each solar panel is roughly 20 square feet, and a 3 kW setup typically uses 6 to 8 high-efficiency monocrystalline panels.

In India, a 1 kW solar plant generates an average of 4 to 4.5 kWh (units) of electricity per day in standard sunny conditions. This translates to roughly 120 to 135 units per month, or 1,500 units annually per kW of installed capacity.

Net-metering uses a bidirectional meter to record both the power you import from the grid and the excess solar power you export to the grid. At the end of the billing cycle, your DISCOM bills you only for the net units consumed (Import minus Export).

With the PM Surya Ghar subsidy, the net out-of-pocket cost for a 3 kW solar system is roughly Rs. 70,000 to Rs. 90,000. Generating Rs. 30,000 worth of free power annually, the system pays for itself in 2.5 to 3 years, followed by 22+ years of free power.

No. Standard grid-tied solar systems automatically shut down during a power cut for safety reasons (anti-islanding) to protect utility workers repairing the lines. To run appliances during power outages, you need a hybrid solar system with battery backup.