Emerging Technologies: Geothermal and Green Hydrogen - Complete Guide for Competitive Exams

Introduction

As the world accelerates its transition toward clean energy, two emerging technologies have captured significant attention from policymakers, researchers, and industry leaders: geothermal energy and green hydrogen. These technologies represent the next frontier in India's quest for energy security, decarbonization, and sustainable development. For competitive exam aspirants, understanding these technologies is not just about staying updated with current affairs but about comprehending the fundamental shift in global energy architecture.

India, being the third-largest energy consumer globally and the third-largest greenhouse gas emitter, faces the dual challenge of meeting its growing energy demands while fulfilling its climate commitments. The country has pledged to achieve net-zero emissions by 2070 and reduce the emissions intensity of its GDP by 45% by 2030. In this context, geothermal energy and green hydrogen emerge as critical pillars of India's clean energy strategy.

This comprehensive guide provides an in-depth analysis of both technologies, their current status in India and globally, policy frameworks, challenges, and most importantly, their relevance for various competitive examinations including UPSC, SSC, Banking, and State PSC exams.

1. Understanding Geothermal Energy

What is Geothermal Energy?

Geothermal energy is the thermal energy generated and stored within the Earth's core, mantle, and crust. This heat originates from the original formation of the planet and from the radioactive decay of materials such as uranium, thorium, and potassium. The temperature at the Earth's core reaches approximately 5,000°C to 6,000°C, making it an enormous reservoir of untapped energy.

Geothermal energy can be harnessed for various applications including electricity generation, direct heating, greenhouse cultivation, industrial processes, and spa therapies. Unlike solar and wind energy, geothermal energy provides baseload power, meaning it can operate 24 hours a day, 365 days a year, regardless of weather conditions.

Types of Geothermal Energy Systems

• Dry Steam Systems: Use steam directly from underground fractures to drive turbines. These are the oldest geothermal power systems, first used at Lardarello, Italy, in 1904.
• Flash Steam Systems: The most common type, where high-pressure hot water is pumped to the surface and flashes into steam to drive turbines.
• Binary Cycle Systems: Use moderate-temperature water (100°C-180°C) to heat a secondary fluid with a lower boiling point, which then vaporizes to drive turbines.
• Enhanced Geothermal Systems (EGS): Engineered reservoirs created where there is hot rock but insufficient natural permeability or fluid saturation. Water is injected under pressure to create artificial fractures.
• Geothermal Heat Pumps: Utilize shallow ground energy for heating and cooling buildings, working at temperatures as low as 10°C-20°C.

Global Geothermal Energy Potential

The global geothermal power installed capacity stands at approximately 16 GW as of 2024, with the United States leading with around 3.7 GW, followed by Indonesia, Philippines, Turkey, and New Zealand. The International Energy Agency (IEA) projects that geothermal energy could potentially meet 8% of global electricity demand by 2050 under net-zero scenarios. Countries like Iceland demonstrate the remarkable potential of geothermal energy, where it meets approximately 65% of primary energy needs and nearly 100% of heating requirements.

2. Geothermal Energy in India: Current Status and Potential

India's Geothermal Potential

India has significant geothermal energy potential estimated at 10,000 MW (10 GW) by the Geological Survey of India (GSI). The country is located within the global geothermal belt, with potential concentrated along plate boundary zones and areas with recent volcanic activity. GSI has identified over 340 geothermal hot springs spread across seven geothermal provinces in India.

Major Geothermal Provinces in India

Puga Valley: India's Geothermal Flagship Project

The Puga Valley in Ladakh has emerged as the most promising geothermal site in India. Located at an altitude of approximately 4,400 meters above sea level, this area exhibits surface manifestations including hot springs, mud pools, and fumaroles, indicating significant subsurface heat. Geological studies suggest temperatures exceeding 250°C at depths of 500-1,000 meters.

ONGC (Oil and Natural Gas Corporation) has taken the lead in developing Puga Valley as India's first geothermal energy project. Key developments include:

• Signing of a Memorandum of Understanding (MoU) with the Union Territory of Ladakh in February 2021
• Drilling of exploratory wells to assess reservoir characteristics
• Plans for initial capacity of 1 MW, scalable to 10-20 MW
• Potential for direct heat applications for space heating in extreme cold conditions

"Puga Valley project represents a strategic milestone in India's pursuit of energy diversification and could serve as a model for geothermal development across the Himalayan region." - Ministry of New and Renewable Energy (MNRE)

Policy Framework for Geothermal Energy

The development of geothermal energy in India falls under the purview of the Ministry of New and Renewable Energy (MNRE). Key policy initiatives include:

• National Geothermal Program: Formulated to assess and harness geothermal potential systematically
• Fiscal Incentives: Concessional customs duty, accelerated depreciation, and income tax holidays for geothermal projects
• Research Support: Funding through the Department of Science and Technology (DST) for geothermal research
• International Collaboration: Partnerships with Iceland, New Zealand, and other geothermal-rich nations

3. Green Hydrogen: The Fuel of the Future

What is Green Hydrogen?

Green hydrogen is hydrogen gas produced through the electrolysis of water using electricity generated from renewable energy sources such as solar, wind, or geothermal power. The term "green" specifically denotes that the production process results in zero carbon emissions, distinguishing it from other forms of hydrogen production.

Types of Hydrogen: A Color Spectrum

• Grey Hydrogen: Produced from natural gas through Steam Methane Reforming (SMR). Accounts for approximately 95% of current global hydrogen production. Emits about 9-12 kg CO₂ per kg of hydrogen.
• Blue Hydrogen: Produced from natural gas but with Carbon Capture, Utilization, and Storage (CCUS) to reduce emissions. Captures 85-95% of CO₂ emissions.
• Green Hydrogen: Produced via water electrolysis using renewable electricity. Zero direct carbon emissions.
• Pink/Purple Hydrogen: Produced using nuclear energy for electrolysis.
• Yellow Hydrogen: Produced using solar power for electrolysis.
• Turquoise Hydrogen: Produced through methane pyrolysis, yielding solid carbon instead of CO₂.
• White Hydrogen: Naturally occurring hydrogen found in geological formations.

The Electrolysis Process

The production of green hydrogen relies on water electrolysis, which splits water molecules (H₂O) into hydrogen (H₂) and oxygen (O₂) using electrical energy. The three main electrolyzer technologies are:

1. Alkaline Electrolyzers (AEL): Most mature technology, lower cost (₹3-4 crore per MW), suited for steady operations. Efficiency: 60-70%
2. Proton Exchange Membrane (PEM) Electrolyzers: Higher efficiency (70-80%), flexible operation, faster response time. Cost: ₹5-7 crore per MW
3. Solid Oxide Electrolyzers (SOEC): Highest efficiency (up to 90% with waste heat), operates at high temperatures (700-850°C). Still in demonstration phase

Global Green Hydrogen Landscape

The global hydrogen market is currently valued at approximately $150-200 billion annually, with production of about 90 million tonnes per year. However, less than 1% of this is green hydrogen. The IEA's Net Zero Emissions (NZE) scenario projects that green hydrogen should reach 30 million tonnes by 2030 and over 300 million tonnes by 2050.

Leading countries in green hydrogen development include:

• Australia: Aiming to become a major green hydrogen exporter, targeting 15 million tonnes production by 2050
• European Union: Green Deal targets of 10 million tonnes domestic production and 10 million tonnes imports by 2030
• China: Largest electrolyzer manufacturing capacity, aggressive domestic targets
• United States: Inflation Reduction Act provides production tax credits of up to $3/kg for green hydrogen
• Saudi Arabia: NEOM project aiming for 1.2 million tonnes green ammonia production by 2026

4. India's National Green Hydrogen Mission

Launch and Objectives

The National Green Hydrogen Mission (NGHM) was approved by the Union Cabinet on January 4, 2023, with an initial outlay of ₹19,744 crore (approximately $2.3 billion) for the period up to 2029-30. This mission represents India's most ambitious clean energy initiative and aims to position the country as a global hub for green hydrogen production, usage, and export.

Key Targets of the Mission

• Production Target: 5 million tonnes of green hydrogen per annum by 2030
• Renewable Energy Addition: 125 GW additional renewable energy capacity
• Electrolyzer Manufacturing: 60-100 GW domestic manufacturing capacity
• Employment Generation: Creation of over 6 lakh (600,000) jobs
• Investment Mobilization: ₹8 lakh crore in total investments
• Emission Reduction: Nearly 50 million tonnes of CO₂ emissions reduced annually
• Fossil Fuel Savings: ₹1 lakh crore in annual imports savings

Strategic Interventions for Green Hydrogen Transition (SIGHT)

The SIGHT program is the flagship financial mechanism under NGHM, with an allocation of ₹17,490 crore. It provides:

• Production-Based Incentive (PBI): Incentives for domestic production of green hydrogen for three years
• Electrolyzer Manufacturing Incentive: Support for setting up electrolyzer manufacturing facilities

In the first tranche of SIGHT allocations (May 2024):

• ₹2,256 crore allocated for green hydrogen production incentives
• ₹440 crore for electrolyzer manufacturing incentives
• Selected beneficiaries include companies like Reliance Industries, Adani Green Energy, NTPC, Greenko, and JSW Energy

Green Hydrogen Hubs

The mission proposes the development of Green Hydrogen Hubs in strategic locations with high renewable energy potential and proximity to demand centers. Identified potential hubs include:

• Gujarat: Kutch region with abundant solar and wind resources
• Rajasthan: Jaisalmer and Barmer districts
• Tamil Nadu: Coastal areas with strong wind resources
• Odisha: Industrial corridors with existing port infrastructure
• Ladakh: Potential integration with geothermal energy

5. Applications of Green Hydrogen

Transportation Sector

Green hydrogen has transformative potential for the transportation sector, particularly for segments where battery electrification faces limitations:

• Heavy-Duty Trucks: Hydrogen fuel cell electric vehicles (FCEVs) offer longer range and faster refueling compared to battery electric vehicles
• Maritime Shipping: Green ammonia and green methanol (derived from green hydrogen) are emerging as viable marine fuels
• Aviation: Sustainable Aviation Fuel (SAF) can be produced from green hydrogen, with targets for 1% SAF blending by 2027
• Railways: India's first hydrogen-powered train prototype was launched in 2023, with plans for retrofitting existing diesel locomotives

Industrial Decarbonization

The industrial sector accounts for approximately 30% of India's CO₂ emissions. Green hydrogen can decarbonize hard-to-abate industries:

• Steel Production: Green hydrogen can replace coking coal in Direct Reduced Iron (DRI) processes. India's steel ministry has launched a Task Force on Green Steel
• Fertilizer Industry: India consumes about 33 million tonnes of fertilizers annually, with hydrogen as a key feedstock. Transition to green hydrogen can significantly reduce emissions
• Oil Refining: Hydrogen is essential for desulfurization and hydrocracking in refineries
• Cement Industry: Green hydrogen can replace fossil fuels in high-temperature kilns

Energy Storage and Grid Balancing

Green hydrogen addresses the critical challenge of renewable energy intermittency. Excess solar and wind power during peak generation periods can be used to produce green hydrogen, which can be stored and later used for power generation during low-renewable periods. This creates a seasonal energy storage solution that batteries cannot economically provide.

6. Challenges and Barriers

Geothermal Energy Challenges

• High Exploration Risk: Subsurface conditions are uncertain, and exploratory drilling is expensive (₹10-20 crore per well)
• High Initial Capital Cost: Geothermal power projects cost ₹15-25 crore per MW, higher than solar (₹4-5 crore/MW) and wind (₹6-7 crore/MW)
• Location Constraints: Viable sites are often in remote, geologically complex areas like the Himalayas
• Long Development Timeline: 5-8 years from exploration to commercial operation
• Limited Policy Support: No specific geothermal energy legislation or feed-in tariffs
• Technical Expertise: India lacks specialized geothermal engineering capabilities

Green Hydrogen Challenges

• High Production Cost: Green hydrogen currently costs ₹300-400 per kg, compared to grey hydrogen at ₹150-200 per kg. The target is to achieve ₹100 per kg by 2030
• Electrolyzer Dependence: India imports 80% of electrolyzer components, primarily from China
• Water Requirements: Producing 1 kg of green hydrogen requires approximately 9-10 liters of pure water, raising concerns in water-stressed regions
• Storage and Transportation: Hydrogen has low volumetric energy density and requires high-pressure tanks (350-700 bar) or cryogenic storage (-253°C)
• Infrastructure Gap: Lack of hydrogen pipelines, refueling stations, and dedicated port terminals
• Greenwashing Concerns: Need for robust certification mechanisms to verify the "green" nature of hydrogen

7. Recent Developments and Updates (2024-2025)

• India's First Green Hydrogen Plant: NTPC commissioned a 5 MW green hydrogen plant at its Simhadri thermal power station in Andhra Pradesh in 2024
• SIGHT Tranche-II: Second round of incentives under SIGHT program launched with enhanced allocation
• International Partnerships: India signed green hydrogen cooperation agreements with Germany, Australia, Japan, and the European Union
• Green Hydrogen Standards: Bureau of Energy Efficiency (BEE) notified certification framework for green hydrogen
• Geothermal Drilling Progress: ONGC completed first phase of exploratory drilling at Puga Valley, confirming subsurface temperature above 240°C
• State-Level Initiatives: Gujarat, Maharashtra, and Tamil Nadu announced state green hydrogen policies with additional incentives
• Green Hydrogen Blending: Gas Authority of India Limited (GAIL) started pilot project for blending 5% green hydrogen in natural gas pipelines
• Export Potential: India and Singapore signed MoU for potential green hydrogen/ammonia exports

8. Expert Analysis and Perspectives

"Geothermal energy and green hydrogen are not competing technologies but complementary pillars of India's clean energy architecture. Geothermal can provide the baseload renewable power needed for electrolysis, creating a synergistic clean energy ecosystem." - Dr. Anil Kakodkar, Former Chairman, Atomic Energy Commission

The convergence of geothermal energy and green hydrogen offers unique opportunities for India. Geothermal energy, particularly from high-enthalpy sites like Puga Valley, can provide the consistent renewable electricity needed for continuous green hydrogen production. This addresses one of the key limitations of solar and wind-powered electrolysis, which is intermittent and results in underutilization of expensive electrolyzer equipment.

Furthermore, the strategic location of geothermal resources in border areas like Ladakh presents dual benefits: energy self-sufficiency for military installations and reduction of diesel transportation logistics in sensitive regions. The development of these technologies aligns with India's broader goals of Atmanirbhar Bharat (Self-Reliant India), energy security, and climate leadership.

9. Exam Relevance: How This Topic Matters

UPSC Civil Services Examination

Prelims: Questions may appear on:

• Types of hydrogen (color spectrum) and their distinguishing features
• Geothermal energy sites in India (Puga Valley, Manikaran, etc.)
• National Green Hydrogen Mission targets and allocations
• Electrolyzer technologies and their characteristics

Mains (GS Paper 3): Potential questions include:

• "Discuss the potential of geothermal energy in India's energy security strategy. What are the challenges in harnessing this resource?"
• "Evaluate the National Green Hydrogen Mission's ability to transform India into a green hydrogen hub. What structural challenges need to be addressed?"
• "Analyze the role of emerging clean energy technologies in India's net-zero pathway."

Essay: Relevant topics include "Clean Energy Transition," "Technology for Sustainable Development," and "Energy Security in the 21st Century."

SSC and Banking Examinations

• Factual questions on mission targets, budgets, and launch dates
• Match the following on geothermal sites and their states
• Current affairs questions on recent developments and partnerships
• Banking awareness questions on green financing and green bonds

State PSC Examinations

• State-specific geothermal potential (if applicable)
• State-level green hydrogen policies and initiatives
• Local environmental and economic impacts

Key Points for Quick Revision

• India's geothermal potential: 10,000 MW
• Geothermal hot springs identified: 340+
• Flagship geothermal project: Puga Valley, Ladakh
• Lead agency for geothermal: ONGC
• National Green Hydrogen Mission launched: January 4, 2023
• NGHM initial outlay: ₹19,744 crore
• Green hydrogen production target by 2030: 5 million tonnes/year
• Additional RE capacity under NGHM: 125 GW
• Electrolyzer manufacturing target: 60-100 GW
• SIGHT allocation: ₹17,490 crore
• Current green hydrogen cost: ₹300-400/kg
• Target green hydrogen cost by 2030: ₹100/kg
• Water required per kg green hydrogen: 9-10 liters
• Global geothermal installed capacity: ~16 GW
• Iceland's geothermal share in primary energy: ~65%

Conclusion

Geothermal energy and green hydrogen represent transformative technologies that can redefine India's energy landscape. While geothermal energy offers the promise of reliable, baseload renewable power, green hydrogen provides a pathway to decarbonize hard-to-abate sectors and position India as a global clean energy leader. The successful realization of these technologies requires coordinated efforts across research, policy, industry, and finance.

For competitive exam aspirants, these topics offer rich content that intersects with multiple subjects including geography (distribution of geothermal resources), economics (cost competitiveness and investment), science and technology (production processes and equipment), environment (emission reductions), and governance (policy frameworks and international cooperation). A comprehensive understanding of these emerging technologies, coupled with analytical ability to assess their challenges and opportunities, will serve aspirants well across various examination formats.

As India progresses toward its 2030 and 2070 climate targets, developments in geothermal and green hydrogen will only gain prominence. Staying updated with these evolving technologies is not just exam-relevant but essential for any informed citizen engaged with India's development trajectory.

Additional Resources

• MNRE Official Website: mnre.gov.in - For policy documents and updates
• National Green Hydrogen Mission Portal: greenhydrogen.gov.in
• Geological Survey of India: gsi.gov.in - For geothermal resource assessments
• International Energy Agency (IEA): Global Hydrogen Review and Geothermal Power Reports
• International Renewable Energy Agency (IRENA): Green Hydrogen Cost Reduction Report
• NITI Aayog Reports: "Investing in Green Hydrogen" and "Clean Energy Transitions"