Maarg Manthan · Topic 12.12

Renewable Energy: Solar, Wind, Geothermal, Tidal, Wave, Biomass, Hydrogen as a Fuel

Geography › Mineral and Energy Resources · Topic 12.12

Renewable energy comes from sources that nature replenishes: sunlight (solar), moving air (wind), the heat of the Earth (geothermal), tides and waves, plant matter (biomass) and, as an energy carrier, hydrogen made with clean power. China leads in solar and wind capacity, followed by the United States, India and Europe. India targets 500 gigawatts of non-fossil capacity by 2030, runs the National Solar Mission, rooftop and farm solar schemes and the National Green Hydrogen Mission, and co-founded the International Solar Alliance.

7 min read · UPSC Prelims · Geography · Mineral and Energy Resources

At a Glance

Sources Sun, wind, heat, tides, biomass
Best solar sites Dry, clear low-latitude regions
India’s target 500 GW non-fossil by 2030
Alliance International Solar Alliance, 2015
Fuel Green hydrogen
Exam link UPSC Prelims, Geography: Mineral and Energy Resources

Where Does It Fit?

This topic completes the macro on mineral and energy resources. It follows atomic energy and brings together the new sources that are expected to replace fossil fuels. Previous topic: Atomic (Nuclear) Energy: Source Minerals (Uranium, Thorium), Production, Distribution, Future Potential. Next topic: coking coal, limestone, water Process Blast furnace to pig iron to steel Largest producer China,…">Iron and Steel Industry: Production Process, Location, Distribution, Global Production, International Trade.

What Are the Main Renewable Sources and Where Are They Best Used?

Source	How it works	Best locations	Examples
Solar energy	Photovoltaic cells turn sunlight into electricity directly; solar thermal plants use mirrors to make steam; solar heaters warm water	Dry, cloud-free regions at low and middle latitudes: deserts and plateaus	Bhadla in Rajasthan, Pavagada in Karnataka, the Atacama in Chile, the Sahara, western China
Wind energy	Wind turns turbine blades connected to a generator	Coasts, hill passes, open plains; the trade winds and westerlies; offshore areas with strong steady wind	Muppandal in Tamil Nadu, Gujarat, Maharashtra, Denmark, the North Sea, Texas
Geothermal energy	Heat from hot rocks and water below ground gives steam for turbines or heat for buildings	Plate boundaries, volcanic regions, hot springs and geysers	Iceland, the Geysers in California, the Philippines, Indonesia, Kenya, New Zealand
Tidal energy	Barrages or turbines use the rise and fall of the tide	Estuaries and bays with a large tidal range	La Rance in France (1966), Sihwa Lake in South Korea; the Bay of Fundy; Gulf of Khambhat and Gulf of Kachchh in India
Wave and ocean thermal energy	Floating devices use waves; ocean thermal plants use the temperature gap between warm surface and cold deep water	Open coasts with strong waves; tropical seas	A wave energy pilot at Vizhinjam in Keralam and low-temperature thermal desalination at Kavaratti are Indian trials
Biomass and biofuels	Burning or digesting plant and animal waste, or making ethanol and biodiesel	Farming regions, sugar mills, cities	Ethanol from sugarcane in India and Brazil; biogas from dung; compressed biogas

The first four sources are described in the next sections, with the details of the Indian programmes. For the classification and trends see Classification and Production Trends of Energy Resources.

How Do Solar and Wind Energy Work in India?

Solar: India lies in a tropical belt with 300 or more sunny days a year in many areas, especially Rajasthan, Gujarat and the Deccan. The National Solar Mission began in 2010; the PM-KUSUM scheme of 2019 supports solar pumps for farmers; and the PM Surya Ghar Muft Bijli Yojana of 2024 aims to put rooftop solar on one crore households. Large parks include Bhadla in Rajasthan, Pavagada in Karnataka and Kamuthi in Tamil Nadu.
International Solar Alliance: launched by India and France at the Paris climate conference in 2015, with its headquarters in Gurugram, to promote solar power among sunshine countries.
Wind: Tamil Nadu has long led in wind power, with the Muppandal area near Kanyakumari, followed by Gujarat, Karnataka, Maharashtra and Rajasthan. India is among the top four countries for wind capacity, and offshore wind is planned off Gujarat and Tamil Nadu. Check the latest ranks and capacity.
Issues: the sun and wind are variable, so the grid needs storage, such as batteries and pumped hydro, flexible gas or hydro power and better transmission. Land, local opposition, curtailment of output and dependence on imported panels and cells, mostly from China, are also concerns.

What About Geothermal, Tidal, Wave and Biomass Energy?

Geothermal in India: hot springs at Puga and Chumathang in Ladakh, Manikaran in Himachal Pradesh and Tattapani in Chhattisgarh are the main sites, but there is no commercial geothermal power plant, and pilot projects are being explored. Check the latest.
Tidal in India: the large tidal range of the Gulf of Khambhat and the Gulf of Kachchh in Gujarat and of the Sundarbans in West Bengal gives potential, but costs and the effect on coastal ecology have so far prevented commercial plants.
Waves: the pilot at Vizhinjam in Keralam showed that wave energy is possible but costly.
Biomass: India uses crop residues, bagasse of sugar mills, dung and waste. The GOBARdhan scheme and the SATAT scheme of 2018 promote biogas and compressed biogas; and ethanol blending in petrol, aimed at 20 per cent, has been reached ahead of schedule, though it raises food and water questions. Check the latest on blending.
Waste to energy: plants at Delhi’s Okhla and elsewhere burn municipal waste, but they face emission and efficiency problems.

What Is Hydrogen as a Fuel?

In short: hydrogen is a fuel that burns to water, but it is not found free in nature, so it must be made, and its climate value depends on how.

Type	Made from	Climate effect
Grey hydrogen	Natural gas by steam reforming	Releases carbon dioxide; most hydrogen today
Blue hydrogen	Natural gas, with carbon capture and storage	Lower emissions
Green hydrogen	Splitting water by electrolysis with renewable power	Nearly zero emissions

Uses: refineries and fertilisers already use hydrogen. Green hydrogen is expected to be important for steel, shipping, long-distance transport and storage of energy.
India’s mission: the National Green Hydrogen Mission, approved in January 2023, aims at 5 million tonnes of green hydrogen a year by 2030, with a large outlay and demand support. Hubs are planned at ports such as Kandla, Paradip and Tuticorin (Thoothukudi).
Challenges: high cost of electrolysers and renewable power, storage and transport of a light gas, and the need for water. See Fertilizer Industry: Production of Nitrogenous, Phosphatic and Potash Fertilizers for the use in fertilisers.

As an analytical point, renewables are changing the geography of energy: from fuel deposits in a few regions to sunlight, wind and land in many places, and from fuel supply to equipment and critical minerals; see gypsum, salt Energy Coal, petroleum, uranium Law MMDR Act, 1957 Key idea…">Types of Mineral Resources: Metallic and Non-Metallic. India’s advantage lies in sunshine, a large market and falling cost; its task is to build the grid, storage and domestic manufacture to match.

Why Is This Topic Important?

Facts Sites and schemes asked
Climate Energy transition
Current affairs Hydrogen and solar missions

What Came Next?

The next macro, on industry, begins with the iron and steel industry: production process, location, distribution, global production and trade. Next topic: Iron and Steel Industry: Production Process, Location, Distribution, Global Production, International Trade.

Key People and Terms

Photovoltaic Direct light-to-electricity cell
Geothermal Heat from inside the Earth
Tidal range Difference between high and low tide
Biomass Plant and animal matter as fuel
Green hydrogen Hydrogen from renewable power
Curtailment Wasted renewable output

Exam Corner

Points to Remember

Bhadla in Rajasthan is a giant solar park.
The International Solar Alliance was launched in 2015.
Muppandal is a wind farm area in Tamil Nadu.
La Rance is the early tidal plant of France.
Green hydrogen mission target: 5 million tonnes by 2030.

Do Not Confuse With

Grey, blue and green hydrogen Gas without capture, gas with capture, water with clean power
Tidal and wave energy Tide barrage versus surface waves
Renewable and non-conventional Hydro is renewable but conventional

Memory Hook

Sun in the desert, wind on the coast, heat on the plate edge, tide in the bay, plants in the field, hydrogen as the carrier.

Mains Angle

Questions ask for the potential, locations and problems of renewable energy and for India’s policies. These points add depth.

Potential Sun, wind, biomass
Grid Storage and transmission
Supply chain Imported equipment

A Question You May Face

An original practice question, not a past paper question.

“Discuss the potential of different renewable energy sources in India and the challenges in achieving the target of 500 GW of non-fossil capacity by 2030.”

How to Answer

Sources Solar, wind, biomass, others.
Schemes Mission, rooftop, KUSUM.
Challenges Grid, storage, imports.
Way forward Manufacture and hydrogen.

GS Relevance

Prelims: types of renewable energy with examples, sites, Indian schemes and missions, International Solar Alliance. GS Paper 3: energy security, climate change and transition.

Frequently Asked Questions

What are the main renewable sources of energy?

The main renewable energy sources are solar, wind, geothermal, tidal, wave, biomass and hydro power, with green hydrogen as a clean fuel made from them. They are replenished by nature, emit little or no carbon dioxide in operation, and are expected to replace fossil fuels in electricity first.

Where are the best sites for solar energy?

The best sites for solar energy are dry, cloud-free regions at low and middle latitudes, such as deserts and plateaus, with strong sunshine through the year. Examples are the Thar desert in Rajasthan, home to the Bhadla park, the Atacama desert in Chile, the Sahara and western China.

What is the International Solar Alliance?

The International Solar Alliance is a treaty-based organisation of sunshine-rich countries launched by India and France at the Paris climate conference in 2015. It has its headquarters in Gurugram, India, and works to promote solar power by lowering the cost of finance and technology.

What is green hydrogen and what is India's mission?

Green hydrogen is hydrogen produced by splitting water with electricity from renewable sources, and it emits almost no carbon dioxide. The National Green Hydrogen Mission, approved in January 2023, aims at 5 million tonnes of green hydrogen a year by 2030 for industry such as fertilisers, refineries and steel.

Does India have geothermal or tidal power plants?

India has no commercial geothermal or tidal power plant at present. Geothermal sites such as Puga in Ladakh, Manikaran in Himachal Pradesh and Tattapani in Chhattisgarh are studied, and the Gulfs of Khambhat and Kachchh and the Sundarbans have tidal potential, but cost and ecological concerns have limited projects.

PYQ Practice — Statement Analysis

1 The International Solar Alliance has its headquarters in Gurugram.

True

It was launched by India and France in 2015.

2 La Rance in France is an early tidal power station.

True

It opened in 1966.

3 Green hydrogen is made from natural gas without capturing carbon.

False

That is grey hydrogen; green hydrogen uses electrolysis with renewable power.

4 India has a large commercial geothermal power plant at Puga.