Implications of Time-of-Day Tariff Policy on Residential Consumers with Grid-Connected Rooftop Solar PV Systems in Ahmedabad, India

In June 2023, the Government of India announced that a time-of-day (ToD) tariff policy would be implemented for electricity consumers by April 2025. The notification proposes time-differentiated billing based on three periods: peak period, normal tariff period, and solar hours. This paper examines the implications of the proposed ToD tariff policy on the electricity bills of residential consumers having grid-connected rooftop photovoltaic (PV) systems by analyzing the changes in their energy charges. The hourly residential electricity consumption data for the year 2018 are collected from the National Energy End-use Monitoring (NEEM) dashboard. A grid-connected rooftop PV system is simulated with the help of System Advisor Model (SAM) software to get the hourly generation data. The energy charges are calculated for four households to understand the potential impact of implementing the ToD tariff policy. The study concludes that the design of ToD tariff (charges/rebates) has the potential to influence the projected savings of the consumers having grid-connected rooftop PV systems. The impact can be neutralized by providing additional incentives for surplus exported electricity. If the consumers with grid-connected rooftop PV systems are penalized more than other consumers because of the ToD tariff, it may jeopardize the ongoing efforts of the central and state governments to accelerate the deployment of the grid-connected solar PV systems.