Green Hydrogen and Clean Energy Technology: Exam Notes

The correct answer is C, Diu. Diu, on the coast of Gujarat, was declared the first union territory in India to run entirely on solar power. It built a solar park on rocky waste land near the coast and added rooftop plants on government buildings, and together these meet its full daytime demand, so the territory no longer draws power from outside during the day. Option A is wrong because the Andaman and Nicobar Islands have long depended on diesel generation and are now adding solar and diesel hybrid systems island by island. Option B is wrong because Chandigarh is promoted as a model solar city with compulsory rooftop installation on larger buildings, but it still draws most of its power from the northern grid. Option D is wrong because Puducherry has rooftop and solar pump programmes but was never declared fully solar powered.

The correct answer is C, Electrolysis of water using renewable electricity. Hydrogen is called green only when the electricity that splits the water comes from a renewable source such as solar or wind, so that no carbon dioxide is released in making it. Option A is wrong because steam reforming of natural gas is the route for grey hydrogen, which is the cheapest and the most widely used route today and releases carbon dioxide to the air; the same route with carbon capture gives blue hydrogen. Option B is wrong because gasification of coal or lignite gives brown or black hydrogen, the route with the highest emissions of all. Option D is wrong because fractional distillation separates petroleum into fractions such as petrol, kerosene and diesel and is not a method of producing hydrogen at all.

The correct answer is B, Blue hydrogen. Blue hydrogen is made by the same fossil route as grey hydrogen, usually steam reforming of natural gas, but the carbon dioxide produced is captured and stored underground instead of being released, so its emissions are much lower though not zero. Option A is wrong because grey hydrogen is exactly the same process without capture, which is why reading the words carbon capture in the question decides the answer. Option C is wrong because pink hydrogen, also called purple hydrogen, is made by electrolysis using electricity from a nuclear plant, which is a non-fossil route. Option D is wrong because turquoise hydrogen is made by pyrolysis of methane, where the carbon leaves the process as a solid that can be stored or sold rather than as a gas that has to be captured.

The correct answer is B, 2 kg of carbon dioxide equivalent per kg of hydrogen. The Ministry of New and Renewable Energy notified the Green Hydrogen Standard for India in August 2023, fixing the limit at two kilograms of carbon dioxide equivalent for each kilogram of hydrogen, averaged over twelve months, and covering the whole chain from water treatment through electrolysis, purification, drying and compression up to the plant gate. Both electrolysis and biomass routes may qualify. Option A is wrong because one kilogram is stricter than the notified Indian limit. Option C is wrong because five kilograms is close to what an efficient grey hydrogen plant emits, which is precisely what the standard is meant to exclude. Option D is wrong because ten kilograms is in the range of coal-based hydrogen and far above any green threshold.

The correct answer is C, Rupees 19,744 crore. The Union Cabinet approved the National Green Hydrogen Mission on 4 January 2023 with this outlay, to be spent up to the financial year 2029-30 across incentives, hubs, pilot projects, research and skilling. Option A is wrong because eight thousand crore rupees matches no component of the mission; the figure of eight lakh crore rupees that appears in mission documents is the total investment the mission hopes to attract, not government spending. Option B is wrong because seventeen thousand four hundred ninety crore rupees is the outlay of the SIGHT programme alone, the largest single component, which supports electrolyser manufacturing and green hydrogen production. Option D is wrong because one lakh crore rupees is the saving in fossil fuel imports that the mission projects, not its outlay.

The correct answer is B, At least 5 million metric tonnes a year. The mission aims to build a green hydrogen production capacity of at least five million metric tonnes a year by 2030, with the potential to rise further if an export market develops, and this is the single figure most often asked from the mission. Option A is wrong because one million metric tonnes is well below the stated target. Option C is wrong because fifty million metric tonnes is the quantity of carbon dioxide emissions the mission expects to avert each year, not the hydrogen it expects to produce, and swapping the two is the standard trap. Option D is wrong because one hundred and twenty-five is the figure in gigawatts of renewable electricity capacity that the mission expects to be added alongside, not a tonnage of hydrogen.

The correct answer is B, Ministry of New and Renewable Energy. The MNRE is the nodal ministry for the mission, frames the guidelines for each of its components and notified the Green Hydrogen Standard for India in August 2023. Option A is wrong because the Ministry of Power handles generation, transmission and distribution of electricity; the Bureau of Energy Efficiency under it was however made the nodal authority for accrediting the agencies that certify green hydrogen, which is why this option is a plausible distractor. Option C is wrong because the Ministry of Petroleum and Natural Gas deals with crude oil, refining and gas, and refineries will be customers for green hydrogen rather than its administrators. Option D is wrong because the environment ministry handles climate negotiations and forest and pollution law, not this mission.

The correct answer is B, Strategic Interventions for Green Hydrogen Transition. SIGHT is the largest component of the mission, with an outlay of seventeen thousand four hundred ninety crore rupees, and it has two parts: incentives for manufacturing electrolysers in India and incentives for producing green hydrogen, both awarded through competitive bidding. Options A, C and D are wrong because they are invented expansions of the same four letters, built from words that sound plausible in an energy scheme. Full forms of mission acronyms are asked exactly as notified, so the safe method is to remember the four key words of this one, strategic, interventions, green hydrogen and transition, and to reject any expansion that replaces interventions with incentives, subsidy or support. The two parts of SIGHT are often asked separately as well, so remember that one window funds electrolyser manufacturing capacity in India and the other funds the production of green hydrogen itself.

The correct answer is A, Electricity and water. A fuel cell converts the chemical energy of hydrogen directly into electrical energy without combustion, so it is not bound by the efficiency limit of a heat engine. Hydrogen is oxidised at the anode, the electrons pass through the external circuit as current, and at the cathode they combine with oxygen from the air to give water, with some heat released as well. Option B is wrong because there is no carbon anywhere in the reaction, which is exactly why hydrogen is attractive as a fuel. Option C is wrong because oxides of nitrogen form when air is burnt at high temperature in an engine, and a fuel cell has no flame and no such high temperature. Option D is wrong because hydrogen peroxide is not the product of this cell; water is, and the cell stops working if it is flooded with it.

The correct answer is B, An energy carrier. Free hydrogen does not occur in any usable quantity on earth, so it has to be made from water or from a hydrocarbon by spending energy, and it then stores and delivers that energy elsewhere. That is the definition of a carrier, like electricity. Option A is wrong because a primary source is one found in nature and used as it is, such as sunlight, wind, flowing water, coal or uranium; hydrogen has to be manufactured first. Option C is wrong because a fossil fuel is formed from buried organic matter over geological time, and although grey hydrogen is made from natural gas, hydrogen itself is not a fossil fuel. Option D is wrong because hydrogen is a gas and not a mineral, and no mineral is renewable in this sense.

The correct answer is B, India. The International Solar Alliance was launched jointly by India and France at the Paris climate conference on 30 November 2015 to bring together countries lying largely between the tropics, and its headquarters is at Gwal Pahari in Gurugram, Haryana. It is the first headquarters of an international intergovernmental organisation to be located in India. Option A is wrong because France is the co-founder of the alliance but not its seat. Option C is wrong because the United Arab Emirates hosts the International Renewable Energy Agency at Masdar City in Abu Dhabi, which is a different body and a common source of confusion. Option D is wrong because Germany hosts the secretariat of the United Nations Framework Convention on Climate Change at Bonn, again a different organisation.