India being a tropical country has an abundance of solar energy; thus, solar energy utilization has become an important component of the renewable energy sector. India has enormous solar energy potential. Approximately 5,000 trillion kWh of energy are incident over India's land area each year, with most areas receiving 4-7 kWh per square meter per day. Karnataka leads India's list of a solar energy-producing states, with a total installed solar power capacity of about 7,100MW, followed by Telangana, Rajasthan, Andhra Pradesh, and Gujarat. In addition, India is now the world's fourth-largest producer of solar power. In this article, we will discuss Solar Energy which will be helpful for UPSC exam preparation.

Role of Solar Energy in the Indian Energy Scenario

• Solar energy-based decentralized and distributed applications have benefited millions of people in Indian villages by meeting their cooking, lighting, and other energy needs in an environmentally friendly manner.
• The social and economic benefits include a reduction in drudgery among rural women and girls engaged in long-distance fuel wood collection and cooking in smoky kitchens, a reduction in the risks of contracting lung and eye ailments, job creation at the village level, and, ultimately, an improvement in the standard of living and the creation of opportunities for economic activities at the village level.

India's Solar Policy

• The Jawaharlal Nehru National Solar Mission (JNNSM), also known as the National Solar Mission (NSM), began in January 2010.
• It was the first time the government of India focused on promoting and developing solar power.
• The scheme's total installed capacity target was set at 20 GW by 2022.
• The target was revised in 2015 to 100 GW, and the government set a solar target of 300 GW by 2030 in August 2021.
• Since 2011, India's solar sector has grown at a compound annual growth rate (CAGR) of around 59%, from 0.5 GW in 2011 to 55 GW in 2021.

Photovoltaic Electricity

• Solar panels are attached to a mounting system made of aluminum. PV cells are composed of at least two semiconductor layers, one positive and one negative in charge.
• Photons are reflected, passed through, or absorbed by a PV cell when exposed to sunlight. When the negative layer of the photovoltaic cell absorbs enough photons, electrons are liberated from the negative semiconductor material.
• These liberated electrons migrate to the positive layer, resulting in a voltage difference.
• When the two layers are connected to an external load, electrons flow through the circuit, causing electricity to be generated.
• Inverters are used to convert the power generated - Direct Current (DC) - to Alternate Current (AC).

*For detailed notes of this topic, check this link Photovoltaic Electricity

Solar-Thermal Electricity

• Solar-Thermal Electricity is generated by a solar collector with a mirrored surface that reflects sunlight onto a receiver that heats a liquid. This heated liquid is used to generate steam, which generates electricity.
• Solar thermal power/electric generation systems collect and concentrate sunlight to generate the high-temperature heat required for electricity generation.
• Solar energy collectors are used in all solar thermal power systems and consist of two main components: reflectors (mirrors) that capture and focus sunlight onto a receiver.

*For detailed notes of this topic, check this link Solar-Thermal Electricity

Solar Thermal Technology

• Solar thermal technologies utilize solar energy to generate thermal energy (heat).
• Solar thermal technologies include flat or parabolic collectors (low, medium, and high-temperature collectors) that concentrate sunlight primarily through the use of mirrors and lenses.
• Solar thermal technologies absorb the heat of the sun and transfer it to useful applications such as heating buildings or water.
• There are several major types of solar thermal technologies in use:
  • Unglazed solar collectors
  • Transpired solar air collectors
  • Flat-plate solar collectors
  • Solar collectors using evacuated tubes
  • Solar concentrators

*For detailed notes of this topic, check this link Solar-Thermal Technology

Concentrated Solar Power

• It takes focused sunlight and converts it into high-temperature heat. This heat is then passed through a conventional generator to generate electricity.
• Solar collectors capture and concentrate sunlight to heat a fluid, which generates electricity. The collectors come in a variety of shapes.
• The most common are parabolic troughs. Parabolic trough power plants use a curved, mirrored trough that reflects direct solar radiation onto a glass tube containing a fluid, heating the fluid due to the concentrated solar radiation, and the hot steam generated is used to rotate the turbine to generate electricity.
• Synthetic oil, molten salt, and pressurized steam are all common fluids.
• Inverters are used to convert the power generated by direct current (DC) to alternating current (AC).

*For detailed notes of this topic, check this link Concentrated Solar Power

Potential of Solar Energy in India

• India has the potential to generate 35 MW/km2 of solar photovoltaic and solar thermal energy.
• Solar energy of approximately 5,000 trillion kWh per year is incident over India's land area, with most parts receiving 4-7 kWh per square meter per day.
• As a result, both technology routes (solar thermal and solar photovoltaic) for converting solar radiation into heat and electricity can be effectively harnessed, providing enormous scalability for solar power in India.
• Rajasthan, northern Gujarat, and parts of the Ladakh region, Andhra Pradesh, Maharashtra, and Madhya Pradesh have very high solar radiation.

*For detailed notes of this topic, check this link Potential of Solar Energy in India

Installed Capacity of Solar Energy in India

• According to MNRE estimates, the current installed capacity of solar in grid-connected power has surpassed 10,000 MW.
• The Government of India and its state governments developed a major initiative known as "The National Solar Mission."
• One of the Mission's main goals is to make India a global leader in solar energy, with an installed solar generation capacity of 100 GW (revised target) by 2022.

International Solar Alliance

• The International Solar Alliance (ISA) was launched on November 30th at the CoP21 Climate Conference in Paris as a special platform for mutual cooperation among 121 solar resource-rich countries located entirely or partially between the Tropics of Cancer and Capricorn.
• The alliance is dedicated to meeting the unique energy needs of ISA member countries.
• The International Solar Alliance's formal name will be International Agency for Solar Policy and Application (IASPA). The ISA secretariat will be based at the National Institute of Solar Energy in Gurgaon.

*For detailed notes of this topic, check this link International Solar Alliance

Luminescent Solar Concentrators

• A luminescent solar concentrator (LSC) is a device that uses a thin sheet of material to trap solar radiation over a large area before directing the energy (via luminescent emission) to cells mounted on the thin edges of the material layer.
• The thin sheet of material is typically made of a polymer (such as polymethylmethacrylate (PMMA)) doped with luminescent species such as organic dyes, quantum dots, or rare earth complexes.

*For detailed notes of this topic, check this link Luminescent Solar Concentrators

International Renewable Energy Agency (IRENA)

• IRENA has 150 member countries and is headquartered in Abu Dhabi.
• The International Renewable Energy Agency (IRENA) is an intergovernmental organization that assists countries in their transition to a sustainable energy future.
• It serves as the primary platform for international cooperation, a center of excellence, and a repository of renewable energy policy, technology, resource, and financial knowledge.
• IRENA promotes the widespread adoption and long-term use of all forms of renewable energy, including bioenergy, geothermal, hydropower, ocean, solar, and wind energy, in the pursuit of sustainable development, energy access, energy security, and low-carbon economic growth and prosperity.

*For detailed notes of this topic, check this link International Renewable Energy Agency (IRENA)

India's Present Capacity of Solar Energy

• In terms of installed solar power capacity, India currently ranks fifth behind China, the United States, Japan, and Germany.
• As of December 2021, India's cumulative solar installed capacity is 55 GW, accounting for roughly half of the country's renewable energy (RE) capacity (excluding large hydropower) and 14% of total power generation capacity.
• Grid-connected utility-scale projects contribute 77% of the 55 GW, with the remainder coming from grid-connected rooftop and off-grid projects.

Significance of Solar Power in India's Commitment to Climate Change Mitigation

• Solar power is a major component of India's commitment to address global warming in accordance with the terms of the Paris Agreement, as well as achieve net zero carbon emissions by 2070.
• PM Modi stated at the United Nations Conference of Parties meeting in Glasgow in November 2021 that India would reach a non-fossil fuel energy capacity of 500 GW by 2030 and meet half of its energy requirements through renewable energy by 2030.
• To boost long-term renewable energy installation, the Centre set a target of 450GW of RE-based installed capacity by 2030, with solar accounting for 300GW of that total.

Conclusion

For a developing country like India, where having electricity in every home was once considered a pipe dream, it is now becoming a reality. The government's 'power for all' initiative is altering the country's socioeconomic structure. To finance solar projects, strong financial measures are required; innovative measures such as green bonds, institutional loans, and clean energy funds can play an important role. Promotion of research and development in the renewable energy sector, particularly in storage technology. Framework should be there for avoiding unnecessary delays in policy decision making and implementation.

FAQs

MCQs

1. Which of the following is a primary advantage of solar energy?

A) High energy density

B) Non-renewable

C) Environmentally friendly

D) High production cost

2. What is the main challenge faced by solar energy systems in India?

A) Limited sunlight

B) High initial investment

C) Lack of grid infrastructure

D) Short lifespan of solar panels

3. Which of the following is the most widely used method of harnessing solar energy?

A) Solar thermal power

B) Photovoltaic cells

C) Solar heating

D) Concentrated solar power

4. What is the main benefit of solar power for rural areas in India?

A) Low cost of electricity

B) Reduced grid dependency

C) High efficiency

D) Immediate availability of energy

5. Which country has the largest installed solar energy capacity in the world?

A) Germany

B) India

C) China

D) United States

GS Mains Questions and Model Answers

Q1: Discuss the role of solar energy in India's energy transition strategy and its potential to reduce carbon emissions.

Answer: Solar energy plays a crucial role in India's energy transition strategy, as it helps reduce reliance on fossil fuels and mitigates carbon emissions. India has set an ambitious target to reach 100 GW of solar power by 2022, aligning with its international climate commitments under the Paris Agreement. Solar energy provides a clean, sustainable alternative to coal, reducing both greenhouse gas emissions and air pollution. The decentralized nature of solar power also supports rural electrification and energy access, which is vital for India’s development. As India continues to scale up its solar capacity, it is expected to significantly reduce its carbon footprint, helping to meet both domestic and global climate goals.

Q2: Evaluate the economic and environmental advantages of transitioning to solar energy in India.

Answer: The transition to solar energy offers significant economic and environmental advantages for India. Economically, it can reduce the dependence on imported fossil fuels, thereby enhancing energy security and stabilizing energy prices. The solar industry also creates jobs in manufacturing, installation, and maintenance, contributing to employment generation. Environmentally, solar power reduces carbon emissions and air pollution, mitigating the effects of climate change. Solar energy is also sustainable, as it relies on an abundant and renewable resource – sunlight. Additionally, with decreasing costs of solar technology, solar energy is becoming increasingly competitive with conventional energy sources.

Q3: What are the technological challenges in the widespread adoption of solar energy in India, and how can they be addressed?

Answer: The widespread adoption of solar energy in India faces several technological challenges. One key challenge is the intermittency of solar power, as it is dependent on sunlight and does not generate electricity during cloudy days or at night. To address this, energy storage technologies, such as batteries, need to be developed and integrated with solar systems to ensure continuous power supply. Another challenge is the integration of solar power into the national grid, which requires upgrading grid infrastructure to handle decentralized and variable power generation. Additionally, there is a need for advancements in solar panel efficiency, reducing the cost per watt of solar power. Encouraging research and development, providing financial incentives, and scaling up manufacturing can address these technological hurdles.

Previous Year Questions on Solar Energy

1. UPSC CSE Prelims 2020:

Question: Which of the following is the major environmental benefit of solar energy?

Answer: The correct answer is (B) Reduction of carbon emissions. Solar energy significantly reduces carbon emissions by providing an alternative to fossil fuels, thus mitigating the effects of climate change.

2. UPSC CSE Mains 2019:

Question: How does India plan to increase its share of solar energy in the national energy mix, and what are the challenges it faces?

Answer: India plans to increase its solar energy capacity through the National Solar Mission, aiming for 100 GW of solar power by 2022. Challenges include high initial costs, land acquisition issues, intermittency, and grid integration. These can be overcome through technological advancements, policy support, and financial incentives.