Renewable Energy and Climate Change Mitigation Technologies

Beyond wetlands, wildlife and climate finance sits a fourth, technology-heavy corner of the Environment syllabus: the actual hardware of cutting emissions. Green hydrogen, rooftop solar, ethanol blending, carbon capture, even geoengineering, all answer the same question UPSC keeps asking in different forms: what is India actually building, and by when? This note works through each mitigation technology with the real scheme names and numbers examiners test, then ties them together under India's Panchamrit commitments.

Green hydrogen: the new industrial fuel

The Union Cabinet approved the National Green Hydrogen Mission on 4 January 2023 with an outlay of ₹19,744 crore. Its headline target: 5 Million Metric Tonnes (MMT) of green hydrogen production capacity per annum by 2030, alongside roughly 125 GW of added renewable capacity to power the electrolysers that make it. Green hydrogen is hydrogen produced by splitting water using renewable electricity, distinct from grey hydrogen (made from natural gas) and blue hydrogen (grey hydrogen with the resulting carbon captured). The Mission's main delivery mechanism is the Strategic Interventions for Green Hydrogen Transition (SIGHT) programme, which incentivises electrolyser manufacturing and green hydrogen production alongside pilot projects in steel, mobility and shipping. The government projects this will unlock over ₹8 lakh crore in investment, create 6 lakh jobs, and avert nearly 50 MMT of CO2 a year by 2030.

Solar power and biofuels: scaling the supply side

PM Surya Ghar: Muft Bijli Yojana is the residential solar push, aiming to put rooftop panels on 1 crore households by March 2027, adding about 30 GW of capacity and giving eligible households up to 300 units of free electricity a month through a capital subsidy (up to 60% of cost for a 2 kW system, capped at 3 kW). Biofuels moved just as fast: the National Policy on Biofuels, 2018, amended in 2022, advanced the target for 20% ethanol blending in petrol (E20) from 2030 to Ethanol Supply Year (ESY) 2025-26, reached roughly five years early, building on 10% blending achieved in June 2022, five months ahead of its own schedule. Feedstock has diversified well beyond sugarcane molasses to include surplus food grains, maize, and residues such as rice straw and bagasse, a hedge against betting on one crop.

Carbon capture, utilisation and storage

Carbon Capture, Utilisation and Storage (CCUS) targets emissions that renewable energy cannot reach: cement, steel and other hard-to-abate industrial sectors, where the chemistry itself releases CO2, not just the fuel burned. NITI Aayog released its CCUS Policy Framework report in November 2022, framing CCUS as essential to India's updated NDC targets (50% non-fossil capacity and 45% lower emissions intensity by 2030, net zero by 2070) precisely because continuing coal dependence makes some emissions unavoidable without it. The report sets an ambition of 750 MTPA of CO2 captured, utilised or stored by 2050, projecting 8 to 10 million jobs, and lists real end uses: green urea, building materials, methanol, ethanol, and enhanced oil recovery. Capture and store locks CO2 away permanently underground; capture and utilise turns it into a product; direct air capture, a different idea again, pulls CO2 from ambient air rather than a factory flue.

Geoengineering: the last-resort category

Geoengineering means deliberate, planet-scale intervention to counter climate change, and UPSC tests it mainly as a classification question. It splits into two families: Solar Radiation Management (SRM), which reflects incoming sunlight back to space (stratospheric aerosol injection, marine cloud brightening), and Carbon Dioxide Removal (CDR), which pulls CO2 already in the atmosphere back out (afforestation, direct air capture, ocean fertilisation). The two solve different problems: SRM cools the planet without touching CO2 concentrations, so it does nothing for ocean acidification and risks disrupting monsoon patterns at scale; CDR reduces atmospheric CO2 but works far more slowly. No geoengineering technique is deployed at climate-relevant scale anywhere today, including in India, it remains a research and governance question, which is why exam statements tend to name one specific technique rather than "engineering the climate" in general.

Ozone-depleting substances and the HFC pivot

A genuine two-step story UPSC likes to compress into one trick question. Step one: the Montreal Protocol (1987) phased out CFCs and HCFCs, the refrigerants destroying the ozone layer. Step two: their replacement, hydrofluorocarbons (HFCs), do not deplete ozone at all, but are extremely potent greenhouse gases, some many thousand times more warming than CO2, molecule for molecule. The Kigali Amendment (2016) closed this loophole by bringing HFCs under a phase-down schedule despite them not being ozone-depleting substances. India, classified as an Article 5 Group 2 country for its high ambient temperatures and cooling demand, agreed to freeze HFC consumption and production at its 2024-26 baseline from 1 January 2028, then cut it 10% by 2032, rising to an 85% cut by 2047. A question describing HFCs as "ozone-depleting" is testing exactly this distinction, and it is false: HFCs are a climate problem, not an ozone problem.

Panchamrit and India's net-zero roadmap

India's mitigation targets across all these technologies eventually route back to one framework: the Panchamrit ("five nectar elements"), announced by the Prime Minister at COP26 in Glasgow on 1 November 2021. The five: raising non-fossil energy capacity to 500 GW by 2030; meeting 50% of energy requirements from renewable energy by 2030; cutting total projected carbon emissions by one billion tonnes between then and 2030; reducing the emissions intensity of GDP by 45% (over 2005 levels) by 2030; and achieving net-zero emissions by 2070. India's updated NDC, submitted after COP26, formally carries the 2030 non-fossil-capacity and emissions-intensity numbers. Every technology above, hydrogen, solar, biofuels, CCUS, delivers one or more of these five numbers, not a stand-alone commitment.

Exam angle

Statement questions on this cluster usually swap a number between two similar-sounding targets: non-fossil energy capacity (500 GW) is not the renewable share of energy consumption (50%); ethanol blending's original 2030 deadline moved to 2025-26, so a question citing the old date is testing whether you noticed; CCUS and CDR both remove carbon but at opposite ends of the supply chain (industrial flue gas versus ambient air); and HFCs are routinely mislabelled as ozone-depleting when they are precisely the gas class Kigali regulates because they are not. Anchor each technology to its one governing number and document, and most traps collapse.

Quick revision points

• National Green Hydrogen Mission (Jan 2023): 5 MMT/year by 2030, ₹19,744 crore outlay, delivered via the SIGHT programme.
• PM Surya Ghar: 1 crore households, about 30 GW of rooftop solar, by March 2027.
• Ethanol blending: E20 target advanced from 2030 to ESY 2025-26 under the National Policy on Biofuels, 2018 (amended 2022), reached ahead of schedule.
• CCUS: NITI Aayog framework (Nov 2022), 750 MTPA capture, utilisation or storage target by 2050.
• Geoengineering: SRM (reflects sunlight) versus CDR (removes CO2), neither deployed at climate-relevant scale anywhere.
• Kigali Amendment: brings HFCs (not ozone-depleting, but high-warming) under the Montreal Protocol; India freezes HFCs from 2028 (2024-26 baseline), cutting 85% by 2047.
• Panchamrit (COP26, 2021): 500 GW non-fossil capacity, 50% renewable energy share, 1 billion tonne emissions cut, 45% emissions-intensity cut (all by 2030), net zero by 2070.

Try a few questions now to see how these targets get tested against each other.