Chennai, despite being responsible for nearly a quarter of Tamil Nadu’s total electricity consumption, only accounts for a modest 6% of the state’s rooftop solar photovoltaic (RTPV) capacity. With a total rooftop capacity of 31 MW, the city is significantly behind the 526 MW capacity of Tamil Nadu as a whole, according to a recent report by the C40 Cities Climate Leadership Group. The report, prepared in collaboration with the Center for Study of Science, Technology and Policy (CSTEP) and ASAR Social Impact Advisors, provides insights into the factors limiting the adoption of rooftop solar systems in the city.
A key factor impeding rooftop solar uptake in Chennai is the prevalence of multi-storey buildings and the complications posed by multiple electricity connections within these structures. The lack of a ‘group net metering’ system in Tamil Nadu further exacerbates the challenge, as power generated by rooftop solar systems cannot be easily distributed across various consumers within a building. This situation discourages the adoption of solar power, especially in residential complexes where multiple tenants share the same space.
The economic model behind Chennai’s electricity tariffs also plays a crucial role. The subsidised electricity for domestic consumers using less than 500 units every two months limits the financial incentive for households to invest in solar systems. The state’s policy that favours more expensive domestic solar panels over imported ones further raises the installation costs, making it a less viable option for many, especially for low and middle-income families.
From a sustainability perspective, the study emphasises the potential benefits of rooftop solar adoption in Chennai. If network charges were not a factor, a domestic consumer installing a 2-kW system could save up to Rs 3.41 lakh over the system’s lifetime. However, network charges reduce these savings by 15%, affecting the financial viability for many potential adopters. Despite these barriers, rooftop solar systems remain a promising solution for reducing carbon footprints and contributing to Chennai’s long-term sustainability goals. However, addressing the gaps in policy and infrastructure will be key to scaling up rooftop solar adoption across the city.
