Renewable energy geography

The first principle

Coal can be dug up and carried to a power plant anywhere, but sunshine and wind must be used where they fall and blow. Renewable energy is therefore tied to geography far more tightly than fossil energy: the output of a solar panel depends on how much sunlight reaches the ground, and the power in wind rises with the cube of its speed, so a site with winds just 25 per cent stronger yields nearly twice the energy. Location, land and the grid that carries the power away decide where renewables can grow, and these same three factors explain both India's huge potential and its uneven development.

The core

What decides solar output

• Insolation. Solar energy reaching the ground depends on the sun's angle (latitude and season), the hours of daylight, and how much the atmosphere absorbs or scatters it. Clouds, dust and humidity cut it most, so dry, clear regions receive the most.
• India's position. Lying largely within the tropics, India receives about 5,000 trillion kilowatt hours of solar energy a year, with most areas getting 4 to 7 kilowatt hours per square metre a day and about 300 clear days. The National Institute of Solar Energy estimated a ground mounted potential of about 748 gigawatts (GW) if only 3 per cent of wasteland were covered with panels.
• Altitude and temperature. Thinner, drier air at height lets more radiation through, and panels work more efficiently when cold, which is why Ladakh, though far north, is among India's best solar sites.

What decides wind output

• Speed and steadiness. Wind power is proportional to air density times the cube of speed, so turbines need sites with strong, steady winds, generally above about 6 to 7 metres per second at hub height.
• Height. Wind is slowed by friction near the ground and is stronger higher up, which is why potential rises with hub height: the National Institute of Wind Energy (NIWE) estimates about 695 GW at 120 metres and about 1,164 GW at 150 metres above ground.
• Topography and season. Winds speed up when funnelled through mountain gaps and along coasts. In India the southwest monsoon supplies the strongest winds, so most wind energy comes between May and September.

Dimensions

Regional variation in solar development

• High potential and high development. Rajasthan and Gujarat combine strong insolation, flat, cheap and largely barren land, and state policies that eased land and grid access. Bhadla in Jodhpur (about 2,245 megawatts) and the Khavda renewable energy park in Kutch, planned at 30 GW, are among the world's largest; Karnataka's Pavagada park (about 2,050 megawatts) was built on land leased from farmers in a drought prone taluk.
• High potential, low development. Ladakh has excellent sunlight but is far from demand and needs long, costly transmission lines across the Himalaya, now being planned.
• Low potential. The north east, Kerala and the Western Ghats have heavy cloud for months, steep or forested land and dense settlement, so they rely more on rooftops and small hydro.
• Demand and policy. States with industrial demand and financially healthy power distribution companies (discoms) (Gujarat, Maharashtra, Tamil Nadu) attract more rooftop and open access solar than poorer states with similar sunshine.

Why wind has a narrow spatial spread

Almost all of India's wind capacity, about 51 GW by mid 2025, lies in eight states: Gujarat, Tamil Nadu, Karnataka, Maharashtra, Rajasthan, Andhra Pradesh, Madhya Pradesh and Telangana. The reasons are partly physical: only coastal stretches, the Kutch and Saurashtra peninsula, the Palghat and Aralvaimozhi gaps behind Muppandal in Tamil Nadu, and the windward edges of the Deccan have strong, steady winds, while the Gangetic plain and the north east have weak winds for most of the year. Seasonality adds to this, since generation peaks in the monsoon and falls sharply in winter, giving a capacity utilisation factor of only about 25 to 35 per cent. Human factors narrow the spread further: the best sites were taken first by small, old turbines, land with clear title is scarce, transmission to carry the power out lags generation, and states have sometimes cancelled or delayed payments. Offshore wind could help, with zones identified off Gujarat and Tamil Nadu, but it remains nascent because foundations, ships and grid links at sea cost much more.

In practice

Potential, targets and progress

India has committed to 500 GW of non fossil capacity by 2030 under its updated Nationally Determined Contribution (2022). By mid 2025 non fossil sources crossed half of installed capacity, five years ahead of the 2030 goal, though coal still produces most electricity because solar and wind run for fewer hours.

Schemes

• Solar parks scheme (2014, Ministry of New and Renewable Energy): ready land and transmission for large plants, as at Bhadla and Pavagada.
• Pradhan Mantri Kisan Urja Suraksha evam Utthaan Mahabhiyan (PM KUSUM) (2019, Ministry of New and Renewable Energy): solar pumps and solarised farm feeders, so that farmers earn by selling surplus power.
• PM Surya Ghar Muft Bijli Yojana (February 2024, Ministry of New and Renewable Energy): subsidy for rooftop solar on one crore homes, with up to 300 units of free power a month.
• Green Energy Corridors (Ministry of Power): dedicated transmission lines to evacuate power from renewable rich states.
• Production Linked Incentive for solar modules (2021): domestic manufacturing of cells and wafers to reduce imports.

Ecological and economic benefits of solar energy

Ecologically, solar plants emit no smoke or carbon while running, and unlike thermal plants they need almost no cooling water, which matters in water stressed Rajasthan. Every unit of solar power replaces coal that would otherwise pollute the air of cities such as Delhi. Economically, competitive auctions have pushed solar tariffs to about ₹2 to 2.5 per unit, cheaper than new coal, the sector employs lakhs of people in installation and maintenance, and PM KUSUM lets farmers earn from sunshine. Agrivoltaics, where crops grow beneath raised panels, keeps land productive, and solar mini grids have brought power to remote hamlets in Jharkhand and Ladakh.

Two short cases

• Great Indian Bustard. Overhead lines from solar and wind plants in Rajasthan and Gujarat kill this critically endangered bird (Ardeotis nigriceps). In M K Ranjitsinh v Union of India (2021) the Supreme Court ordered power lines in its habitat to go underground; in March 2024 it modified this for practicality and recognised a right against the adverse effects of climate change.
• Bhadla. The park turned a hot, sparsely populated desert into a power hub, but dust storms force frequent panel cleaning, and water and skilled staff must come from outside.

Issues and way forward

• Grid and storage. Solar output falls to zero at sunset just as demand peaks, so the Central Electricity Authority has called for large battery and pumped storage capacity alongside new transmission.
• Land and commons. Desert "wasteland" is often grazing land used by pastoralists and habitat for wildlife; rooftop solar, canal top panels and agrivoltaics reduce this conflict.
• Import dependence. Most cells and wafers still come from China, so the Production Linked Incentive and the approved list of models and manufacturers are meant to build domestic supply chains.
• Discom finances. Delayed payments by state discoms deter investors; the late payment surcharge rules (2022) improved this.
• Old wind sites. Repowering small, old turbines with taller, larger ones, under the national repowering policy for wind (2016), can raise output from the best windy sites.
• Other renewables. Hydropower is concentrated in the Himalaya and the north east, geothermal sites such as Puga in Ladakh remain untested at scale, and the National Green Hydrogen Mission (2023) aims to use cheap solar and wind power to make hydrogen for steel, fertiliser and refining.

Common confusions

• Capacity and generation. Capacity is the maximum output in GW; generation is the energy actually produced. Solar and wind have lower capacity utilisation than coal, so their share of capacity is larger than their share of electricity.
• Insolation and temperature. The hottest places are not always the best for solar, since heat lowers panel efficiency; clear skies matter more, which is why cold Ladakh rates highly.
• Non fossil and renewable. The 500 GW target counts nuclear and large hydro as non fossil, not only solar and wind.

For the exam

• Keyword bank: insolation, cube law of wind power, hub height, capacity utilisation factor, solar parks, Bhadla, Pavagada, Khavda, rooftop solar, agrivoltaics, PM KUSUM, PM Surya Ghar, Green Energy Corridors, offshore wind, Great Indian Bustard, 500 GW non fossil target.
• Previous year questions: Practise the previous year questions on this topic →
• Use in an answer:
  • Introduction (data): India receives about 5,000 trillion kilowatt hours of solar energy a year, and its estimated wind potential at 150 metres exceeds 1,100 GW, yet these resources are concentrated in a handful of states.
  • Introduction (judgement, quote or report): In M K Ranjitsinh v Union of India (2024) the Supreme Court recognised a right against the adverse effects of climate change, tying clean energy to fundamental rights.
  • Conclusion: Geography gives India abundant sun and strong but localised wind; turning this into reliable power needs storage, transmission and fair use of land.
  • Conclusion: A transition that places panels on rooftops, canals and farms rather than only on grasslands can serve both climate goals and rural livelihoods.