Coal imports by Indian coal utilities during the first half of 2019 rose 53.4% from a year earlier to 35.47 million tonnes, data provided by India's Central Electricity Authority (CEA) showed.
Demand for seaborne coal imports in India has risen because of a fast rising population and the unavailability of alternative fuels such as natural gas.
Imports for power plants at the port of Mundra, in western India's state of Gujarat, made up 42% of all imports by Indian utilities during the first half of 2019.
Imports by Adani Power Ltd's Mundra plant more than quadrupled from a year earlier to 9.01 million tonnes, while coal shipments by Tata Power Ltd's utility rose over 6% to 6.07 million tonnes.
The utilities have been ramping up imports of thermal coal after India's top court in October eased their earlier stance and paved the way for passing on increased generation costs to consumers.
The power plants were forced to cut imports and slash electricity generation after the court barred them from increasing prices for customers in 2016, after their coal supplier Indonesia raised the price of coal.
NTPC Ltd, India's largest electricity generator, shipped in 1.4 million tonnes of coal to various ports during six months ended June 2019, about 11 times of what it imported a year ago.
Coal is among the top five commodities imported by India, and about three-fifths of its thermal coal imports come from Indonesia, while less than one-sixth is imported from South Africa.
Thermal coal imports rose at the fastest pace in four years in 2018, after two straight years of decline.
Indian utilities are importing more as the government has failed to open the industry to competition because bureaucratic indecision and resistance from unions has stalled the passage of a liberalization policy approved by the country's cabinet 16 months ago.
Higher Indian coal imports are a boon for international miners such as Indonesia's Adaro Energy, U.S. coal miner Peabody Energy Corp and global commodity merchants such as Glencore PLC.
They also undercut efforts by Prime Minister Narendra Modi's government to cut imports and place additional burdens on India's debt-ridden thermal power sector.