BENGALURU: India's utility solar capacity grew by a whopping 72% in 2017-18 over the previous year, says solar consultancy Bridge To India in its latest annual report on the sector. It installed 9.1GW of utility solar against 5.5GW in 2016-17.Total solar installation was 10.4GW, the rest comprising rooftop solar plants and off-grid solutions, taking the country’s cumulative solar capacity to 24.4GW.Solar capacity addition in 2017-18 was higher than that of all other energy sources, both conventional and renewable, combined, the report notes. In comparison coal and wind only added 4.6GW and 1.7GW respectively.Among the states, Karnataka added the most capacity at 4.1GW, which was 46% of total capacity installed in 2017-18. This also makes Karnataka the state with the largest commissioned solar capacity in the country, at 5.2GW. The report notes that the open access market in the state grew substantially because of favourable exemptions under its solar policy, but that these are being phased out from this year.The second highest cumulative capacity was in Telangana (3.28GW), followed by Rajasthan (2.3GW), Andhra Pradesh (2.28GW) and Tamil Nadu (1.86GW).Adani Green Energy, Renew Power and Acme Solar were the top three developers in 2017-18, installing a total capacity of 2.3GW between them, according to the study.“Indian solar market has grown spectacularly over last four years. But we are still only at 24.4GW, way short of the 100GW target,” said Vinay Rustagi, Managing Director, Bridge to India.The government had set the 100GW target in 2015, as part of an overall renewable energy target of 175GW for 2022. Recently, the new and renewable energy ministry announced it expects to surpass this target to reach 227GW, including 113.5GW of onshore solar and another 31GW of floating solar and wind.The study, however, estimates that capacity addition will be lower in 2018-19 because of a slowdown in tender activity in late 2016 and early 2017. The majority of installations this year were driven by state government tenders. “While falling prices and government support have helped in boosting demand, supply side factors like land and transmission still remain a concern,” said Rustagi.There is also the fear of safeguard duty being imposed on imported solar equipment, as the Directorate General of Trade Remedies examines a complaint from domestic manufacturers on the matter. In early January, a provisional safeguard duty of 70% for a period of 200 days had been suggested, but a final decision will be taken after a public hearing later this month.As in previous years, rooftop solar installations have been lagging, says the report. Total rooftop capacity stood at 2.4GW as of March 2018, with around 1GW having been added in 2017-18, against a target of 40GW by 2022.“Growth in rooftop solar slowed down marginally in the year due to GST and safeguard related uncertainty,” the study says.“We have bid out 10,500 MW of solar projects this year, as against 5,000 MW in 2016-17,” said Anand Kumar had said to ET in March. “We have also brought solar tariffs down to affordable levels.”Solar tariffs reached a record low of Rs 2.44 per unit at an auction held by Solar Energy Corporation of India (SECI) for 500 MW of projects at the Bhadla Solar Park in Rajasthan in May 2017, but have been rising slowly since then. Even so, solar tariffs compare favourably with the cost of thermal power.