New Delhi, July 6 -- India is planning to introduce a standardised energy-efficiency labelling system for batteries used with solar photovoltaic (PV) panels and large-scale energy storage systems. The rating will range from one to five stars, with Watt-hour (Wh) serving as the key metric for the classification, according to two people aware of the development and a government document reviewed by Mint.

The proposed system will be implemented on the lines of the energy-efficiency labelling programme for electrical appliances run by the state-owned Bureau of Energy Efficiency (BEE) under the Union power ministry, where higher ratings indicate greater energy efficiency and improved generation and storage performance.

The new framework, lik...