The Kerala State Electricity Regulatory Commission (KSERC) has issued clarifications regarding the tariff structure and conditions for electricity supplied to Electric Vehicle (EV) charging stations, particularly those that have Solar PV plants. These clarifications follow the Tariff Order dated December 5, 2024.
The KSERC had previously approved a Time of Day (ToD) tariff for EV charging stations, applicable to both Low Tension (LT) and High Tension (HT) voltage levels. Under this tariff, the day is divided into two zones: ‘Solar hours’ from 9 AM to 4 PM, and ‘Non-Solar hours’ for the remaining time. During solar hours, the tariff is set at 0.70 times the Average Ruling Tariff (ART), while during non-solar hours, it increases to 1.30 times the ART. Importantly, EV charging stations are exempt from fixed charges and demand charges under this structure.
The tariff structure has been designed to align with the ‘Guidelines for Installation and Operations of Electric Vehicle Charging Infrastructure-2024’ issued by the Ministry of Power, Government of India. These guidelines aim to encourage EV charging during solar hours by making it more affordable while discouraging charging during non-solar hours by imposing a higher tariff. The overall goal is to promote sustainable energy use by encouraging EV charging when solar power is abundant.
For EV charging stations equipped with Solar PV installations, the KSERC intends to incentivize the use of solar power during solar hours and reduce dependence on grid power during non-solar hours. The commission has provided specific procedures for energy adjustment, billing, and the banking of solar power for these stations.
According to the new clarifications, energy exported from Solar PV plants between 9 AM and 4 PM can be used to offset the electricity imported during the same hours within a billing cycle, without any additional charges. Likewise, any electricity exported during non-solar hours can be adjusted against energy imported during the same period, also without charges.
In cases where there is surplus energy exported to the grid during solar hours, this energy can be adjusted against the import of power during non-solar hours, using a multiplication factor of 7/13. The KSERC has clarified that no grid support charges will be levied for this adjustment. Any surplus energy remaining at the end of the billing period can be carried forward and banked for future use, with the banking period extending up to the settlement period, currently set to end on March 31st. However, banking charges of 5% and applicable grid support charges will apply to this banked energy.
If there is any net surplus energy left at the end of the settlement period after adjustments, it will be settled at the Average Power Purchase Cost (APPC) or another rate approved by the KSERC. Additionally, EV charging stations with Solar PV systems have the option to install Battery Energy Storage Systems (BESS), which would allow them to store surplus solar energy for use during non-solar hours. This would further reduce their reliance on grid power during non-solar periods.
The KSERC has emphasized that the goal of these measures is to encourage EV charging during solar hours. It expects EV charging stations, including those set up by the Kerala State Electricity Board (KSEB), to provide appropriate incentives that support this objective.
These new procedures and tariffs will remain in effect until further orders or regulations are issued by the commission.
