kWh produced compared to average emissions from their European Union (EU-27) counterparts. The central government plans to retire coal-based plants that are at least 25 years old and contributing excessive pollution, totalling 11,000 MW of capacity. As of 2018 there is no similar retirement plan for the captive power sector. In 2020 Carbon Tracker estimated that phasing out 20 years or more old coal-fired plants and the coal fired plants under construction with electricity sale price exceeding INR 4/kWh with new renewables is more economical as these coal fired plants are imposing heavy financial burden on Discoms. Some diesel generator plants and gas turbine plants were also decommissioned in 2016 though they are best suitable for catering ancillary services. Integration of renewable power India has committed to install 275,000 MW renewable energy capacity by 2027. The existing base load coal and gas based power plants need to be flexible enough to accommodate the variable renewable energy. Also ramping up, ramping down, warm start up, hot start up capabilities of existing coal based power stations are critical to accommodate the frequent variations in renewable power generation. It is also examined to use the retired coal based electric generators as synchronous condensers for improving the grid inertia when it is dominated by static power generation sources like solar and wind power. As the solar power plants remain idle during the night hours, reactive power capability of the inverters installed as part of the solar power plant can also be used during the night time for solving the problem of very high voltage which occurs due to low loads on the transmission lines. Natural gas supply constraints The installed capacity of natural gas-based power plants (including the plants ready to be commissioned with the commencement of natural gas supply) was nearly 26,765 MW at the end of the financial year 2014–15. These plants were operating at an overall plant load factor (PLF) of 22% due to a severe shortage of natural gas in the country, and the fact that imported liquid natural gas (LNG) was too expensive for power generation. Many power stations were shut down throughout the year for a lack of natural gas supply. The natural gas shortage for power sector alone was nearly 100 million cubic metre per day at standard conditions. The break-even price for switching from imported coal to LNG in electricity generation was estimated to be approximately