Renewable Energy in India: Sources, Missions and PYQs

The correct answer is D, anthracite. Anthracite is the oldest and hardest grade of coal, with the highest proportion of carbon, so it gives the most heat for its weight and burns with a clean, almost smokeless flame. Option A is wrong because bituminous coal, though the grade most widely used in industry and in power stations, stands below anthracite in carbon content and produces more smoke. Option B is wrong because lignite, also called brown coal, is a low grade with high moisture, used mainly in power stations built at the mine itself. Option C is wrong because peat is the first stage of the process, little more than partly decayed plant matter, with the least carbon and the most moisture of the four. The rising order to remember is peat, lignite, bituminous, anthracite.

The correct answer is D, lower. A geothermal plant takes steam or hot water from a natural underground reservoir, whose temperature is set by the rock and rarely approaches what a furnace can produce, so both the temperature and the pressure at the turbine are well below those of a coal-fired steam plant, and the thermal efficiency is correspondingly lower. Options B and C are wrong for the same reason: no natural reservoir is hotter than a boiler fired deliberately, and quoting higher values confuses the depth of the source with its temperature. Option A is wrong because the two are not comparable either; the gap is large enough that geothermal turbines are designed differently, often working on a separate fluid that boils at a low temperature. What geothermal loses in efficiency it gains in fuel cost, which is nil, and in emissions.

The correct answer is B, Gurugram in Haryana. The alliance has its secretariat on the campus of the National Institute of Solar Energy at Gwal Pahari in Gurugram, and because it rests on a framework agreement among its members it is the first treaty-based international organisation to be headquartered in India. Option A is wrong because although the alliance is closely linked with the Indian government, the secretariat is not in New Delhi itself. Option C is wrong because Bengaluru hosts many renewable energy firms and research bodies but no organ of the alliance. Option D is wrong because Paris is where the alliance was launched, jointly by India and France at the climate conference of 2015, and candidates often confuse the place of launch with the seat of the secretariat.

The correct answer is C, 2010. The mission was launched in January 2010 as one of the eight national missions under the National Action Plan on Climate Change, and its aim was to make solar power competitive by building capacity in stages and by supporting domestic manufacturing. Option A is wrong because 2006 is the year the ministry took its present name, the Ministry of New and Renewable Energy, which is a separate landmark often placed among the options. Option B is wrong because 2008 is the year the National Action Plan on Climate Change itself was released, that is the umbrella under which the mission was later launched. Option D is wrong because 2015 is the year of the Paris climate conference and of the launch of the International Solar Alliance, five years after the national mission began.

The correct answer is B, natural gas. Natural gas is a fossil fuel formed over millions of years from buried organic matter; the stock is fixed, so every unit burnt is gone, and it releases carbon dioxide when burnt, although less than coal for the same heat. Option A is wrong as an answer because tidal energy comes from the rise and fall of the sea caused by the pull of the moon and the sun, which will not run out. Option C is wrong as an answer because biomass is agricultural residue, dung and other plant matter, which grows again each season and is therefore renewable, though it must be used no faster than it regrows. Option D is wrong as an answer because geothermal energy draws on heat continuously produced within the earth, tapped in India at sites such as Puga valley and Manikaran.

The correct answer is C, Tamil Nadu. Muppandal lies in the far south of the state near Kanyakumari, where the wind pushed through a break in the Western Ghats blows strongly and steadily for much of the year, and Tamil Nadu has long been among the leading wind states of the country. Option A is wrong because Gujarat, although a major wind state with farms along its coast, is not where Muppandal is. Option B is wrong because Rajasthan has large wind farms around Jaisalmer and huge solar parks such as Bhadla, but Muppandal is not one of them. Option D is wrong because Maharashtra has wind capacity on the Sahyadri ridges and a great deal of sugar mill cogeneration, yet the site named in the question belongs to the deep south of the peninsula.

The correct answer is A, Ladakh. The Puga valley in eastern Ladakh carries hot springs and sulphur deposits and is the best studied geothermal field in the country, the heat coming from the young mountain building of the Himalaya. Option B is wrong because Uttarakhand has hot springs of its own but none of them forms the standard textbook example; the named Himachal site is Manikaran in the Parvati valley. Option C is wrong because Sikkim is known for its small hydro projects on steep streams rather than for geothermal fields. Option D is wrong because Meghalaya is associated with coal and limestone and with very heavy rainfall, not with geothermal energy. The three sites worth remembering together are Puga in Ladakh, Manikaran in Himachal Pradesh and Tattapani in Chhattisgarh.

The correct answer is A, the Gulf of Khambhat and the Gulf of Kachchh. Both are long, narrowing inlets on the coast of Gujarat, and such a shape funnels the incoming tide so that the difference between high and low water is large, which is exactly what a tidal power scheme needs; the Sundarbans coast is the other site usually named. Option B is wrong because the Palk Strait between India and Sri Lanka is shallow and its tidal range is small. Option C is wrong because the Andaman Sea is associated with rich marine biodiversity and with the seismic activity of the island arc rather than with a large tidal range. Option D is wrong because the sea around Lakshadweep is being studied for ocean thermal energy, which uses the temperature difference between surface and deep water, not the tide.

The correct answer is B, 2008. The plan set out eight missions covering solar energy, enhanced energy efficiency, sustainable habitat, water, the Himalayan ecosystem, a green India, sustainable agriculture and strategic knowledge for climate change, and every later programme in this field refers back to it. Option A is wrong because 2005 is the base year used for India's emissions intensity target rather than the year of the plan, and the two are easy to confuse. Option C is wrong because 2012 is the year the first commitment period of the Kyoto Protocol ended. Option D is wrong because 2016 is the year the Paris Agreement entered into force, and India ratified it that year; the national plan is eight years older and is a domestic document rather than an international one.

The correct answer is C, twenty-five megawatts. Projects of this size and below fall under the small hydro programme of the Ministry of New and Renewable Energy, while larger schemes are handled as conventional hydro power by the Ministry of Power. Option A is wrong because five megawatts marks the boundary of what is often called mini hydro within the small hydro family, not the outer limit of the category. Option B is wrong for a similar reason: ten megawatts is the limit used in several other countries and in some international definitions, which is why it appears as a distractor. Option D is wrong because a hundred megawatt project is a full-sized hydro station with a substantial reservoir or diversion works and is never treated as small hydro anywhere.

The correct answer is B, the Ministry of New and Renewable Energy. It grew out of a department for non-conventional energy sources created in 1982, became a full ministry in 1992 and took its present name in 2006, and India is among the very few countries in the world to have a separate ministry devoted to this sector. Option A is wrong because the Ministry of Power handles generation, transmission and distribution of conventional electricity, including thermal and large hydro stations. Option C is wrong because the Ministry of Environment, Forest and Climate Change deals with forests, wildlife, pollution control and India's position in climate negotiations rather than with building renewable capacity. Option D is wrong because the Ministry of Petroleum and Natural Gas is concerned with oil and gas, which are fossil fuels and the opposite of the sector in question.