Rooftop solar capacity addition saw a 6.25% growth to 1.7 gigawatts in 2023, supported by various factors like reduced installation cost, according to Mercom Capital.The rooftop capacity addition was at 1.6 GW in 2022, the US-based research firm said in its latest report.In October-December 2023, 406 megawatts of rooftop solar was added, down 15.9% from 483 MW in the last quarter of 2022, the 'Mercom India Rooftop Solar Market Report' said.Cumulative rooftop solar installations reached 10.5 GW at the end of December 2023. Residential installations were the primary driver of capacity additions in 2023. However, growth was marginal as many commercial and industrial consumers waited for module prices to stabilise to lower their capital investments.The residential segment accounted for over half of the capacity additions in 2023, followed by C&I segments."Rapidly falling system costs, increasing electricity rates, incentives for residential installations, and attractive return on investments for the C&I segment are all fuelling demand, which is expected to accelerate in 2024. The wait for prices to continually drop is over, and the resurgence in construction activity has begun," said Raj Prabhu, CEO of Mercom Capital Group.Rooftop solar tenders totalling 1.2 GW were issued in 2023, down 45.7% year-on-year. Uttar Pradesh New Energy Development Agency drove tender activity in 2023, accounting for 44.2% of announced tender capacity, the report said.Tenders to add rooftop solar systems on government buildings across India accounted for nearly 57% of the announced total solar tender capacity.Gujarat was the leader in installation, accounting for 27.3% of cumulative solar rooftop installations, followed by Maharashtra and Rajasthan, with 13.3% and 8.1% share respectively.The top 10 states accounted for 77.3% of cumulative rooftop solar installations as of December 2023. The average cost of rooftop solar systems fell for the fifth straight quarter.