India, with a staggering 2,514 million tons of CO₂ emissions in 2022, ranks 3rd among the top greenhouse gas (GHG) emitters globally. Achieving its ambitious Net Zero target by 2070 necessitates a significant shift from coal and other fossil fuels to sustainable energy sources. This blog explores the detailed calculations behind India's emissions, the renewable energy capacity required for the transition, and the multifaceted challenges the nation faces in this journey.

In 2022, India’s total primary energy consumption stood at 42.5 EJ (Exajoule= 10^18 Joules), with CO₂ emissions from fossil fuels—Coal, Oil, and Natural Gas (CONG- a nomenclature I have given)—amounting to 2,514 million tons. Among these, coal was the dominant contributor, accounting for 72.2% of emissions, followed by oil at 24.2%, and natural gas at 3.6%.

In terms of physical consumption, this translates to approximately 821.5 million tons of coal, 1,671 million barrels of oil, and 55.15 billion cubic meters of natural gas. The sheer scale of these numbers underscores the magnitude of the challenge India faces in phasing out these energy sources while maintaining economic growth and energy security.

Through this analysis, an attempt is made to shed light on the renewable energy capacity needed to offset these emissions and the structural, technological, and economic complexities of achieving a carbon-neutral future for India.

To achieve Net Zero Carbon, India must rapidly decarbonize its power grid while integrating and coupling industrial processes and mobility solutions into its clean energy framework.

Last year, India’s installed capacity was approximately 430 GW, producing around 1,750 TWh of electricity annually, with coal accounting for about 1,316 TWh. This heavy reliance on coal underscores the scale of transformation required to achieve Net Zero.

Understanding Net Zero

Net Zero doesn’t imply the complete absence of emissions but rather achieving a balance where emissions are offset by equivalent removal or absorption through natural and technological carbon sinks. Eliminating India’s 2,514 million tons of CO₂ emissions of 2022 requires a substantial transition from fossil fuels to renewable energy sources, primarily solar and wind and others like Hydro, Nuclear only playing supportive role. While this goal seems straightforward, the intricacies of replacing coal-generated power, ensuring energy security, and scaling carbon sink solutions make it a highly complex endeavor.

Calculating Renewable Energy Requirements

India, with annual CO₂ emissions of 2,514 million tons, faces a monumental challenge in transitioning to a Net Zero Carbon economy. Achieving this goal requires a large-scale deployment of renewable energy, specifically solar and wind.

CO₂ Emissions and Energy Requirements

The table below summarizes the CO₂ emissions and energy requirements for coal, oil, and natural gas, using the emission factors of 0.95 kg CO₂/kWh for coal, 0.75 kg CO₂/kWh for oil, and 0.45 kg CO₂/kWh for natural gas.

Replacing emissions from coal, oil, and natural gas (CONG) entails developing sufficient renewable capacity to compensate for fossil fuel-based energy production.

Assuming a 70:30 split between solar and wind energy based on their potential in India and the following factors:

1. Solar and Wind Capacity Utilization Factors (CUF):

   • Solar: 20%

   • Wind: 25%

2. Transmission and Distribution (T&D) Losses: 10%

The total renewable energy required to replace 2,514 million tons of CO₂ emissions can be estimated. Here’s the step-by-step process:

A.     Step-1: Annual Energy Demand Replacement:

1. • Each ton of CO₂ corresponds to a specific amount of energy from coal, oil, and gas.

   • Adjust for T&D losses by multiplying the energy demand by 100/(100-10).

2. Step-2: Energy Contribution by Solar and Wind:

   • 70% of the total energy demand will be met by solar, and 30% by wind.

3. Step-3: Calculating Capacity Requirements:

   • Capacity required for each source is calculated as:

                             Capacity=Energy Demand (in TWh) /(CUF× Hours in a Year)

 Capacity Calculation and Challenges

Total Energy Required to Offset CO₂ Emissions

1. CO₂ Emissions from Coal to Offset: 1816 million tons of CO₂.
2. Coal Emission Offset Rate: 0.95 tons of CO₂ per MWh (average emission factor of Indian coal).
3. Energy Required:
    Energy Required (MWh/year) = CO₂ emissions (tons) / Emission factor (tons/MWh)
  = 1816,000,000 / 0.95 = 1911.58 TWh/year. 

4.  CO₂ Emissions from Oil to Offset: 608 million tons of CO₂.
5. Oil Emission Offset Rate: 0.75 tons of CO₂ per MWh (average emission factor of Oil).
6. Energy Required:
    Energy Required (MWh/year) = CO₂ emissions (tons) / Emission factor (tons/MWh)

= 608,000,000/0.75= 810.67 TWh/year

7. CO₂ Emissions from Natural Gas to Offset: 200 million tons of CO₂.
8.  NG Emission Offset Rate: 0.45 tons of CO₂ per MWh (average emission factor of NG).
9. Energy Required:
    Energy Required (MWh/year) = CO₂ emissions (tons) / Emission factor (tons/MWh)

  = 90,000,000/.45= 200 TWh / year

10. Total Energy Required = 1911.58+810.67+200= 2922.25 TWh

11. Adjusting for T&D Losses (10%):
  Energy Generated (MWh/year) = Energy Required / (1 - T&D Loss Factor)
  = 2922.25 / 0.9 ≈ 3246.94 TWh/year~ 3247 TWh/Year

Therefore, around 3247 TWh of additional clean energy is required to be generated every year from Solar & Wind sources to replace Co2 emission of 2022.

Energy Split for Solar and Wind

1. Solar Energy Contribution (70%):
  Solar Energy (MWh/year) = 70% × 3247= 2272.9 TWh/year

   ~ 2273 TWh/year
2. Wind Energy Contribution (30%):
  Wind Energy (MWh/year) = 30% × 3247 = 974.1 TWh/year

   ~974 TWh/year

Capacity Required for Solar and Wind

Solar Capacity

1. Solar CUF: 20% (1,752 MWh/year per MW).
2. Solar Capacity (MW):
  Solar Capacity = Solar Energy (MWh/year) / CUF output (MWh/year per MW)
  = 2273 TWh/ 1,752 hrs ≈ 1297.4 GW
3. Solar Capacity (GW):
  Solar Capacity = 1297.4 GW.

Wind Capacity

1. Wind CUF: 25% (2,190 MWh/year per MW).
2. Wind Capacity (MW):
  Wind Capacity = Wind Energy (MWh/year) / CUF output (MWh/year per MW)
  = 974.1 TWh/ 2,190 hrs ≈ 444.8 GW.
3. Wind Capacity (GW):
  Wind Capacity = 406,739 / 1,000 ≈ 444.8 GW.

Around 1742.2 GW of capacity (1297.4 GW of Solar and 444.8 GW of Wind generation capacity) is required to generate required 3247 TWh annually.

Financial Considerations

1. Solar Costs:
  • Cost per MW for solar: ~$700,000.
  • Total Solar Cost = 1,297,000 MW × 700,000 $/MW ≈ 907.9 billion USD.
2. Wind Costs:
  • Cost per MW for wind: ~$1,200,000.
  • Total Wind Cost = 444,800 MW × 1,200,000 $/MW ≈ 533.76 billion USD.
3. Total Cost: = 907.9+533.76= 1,441.67 billion USD.

4. Associated Transmission & Cost @25% of Generation Cost= 0.25* 1441.67 billion USD.

5. Total Cost= US$ 1441.67*1.25= US$ 1802 billion

 An estimated US$ 1.8 trillion will be required to establish the necessary generation, transmission, and distribution capacities to meet India's renewable energy and Net Zero targets. This includes investments in large-scale renewable energy installations, transmission infrastructure to connect generation sites with consumption centres, and distribution networks to ensure reliable and equitable energy access across the country.

Land Requirements

Solar Land Requirements

1. Land required per MW of solar: ~5 acres.
2. Total Solar Land Requirement:
  Land (acres) = 1,188,549 MW × 5 acres/MW = 5,942,745 acres.
3. Land in km²:
  Land (km²) = 5,942,745 / 247.1 ≈ 24,043 km².

Wind Land Requirements

1. Land required per MW of wind: ~1 acre (direct), but spacing requires larger areas.
2. Total Wind Land Requirement:
  Land (acres) = 406,739 MW × 1 acre/MW = 406,739 acres.
3. Land in km²:
  Land (km²) = 406,739 / 247.1 ≈ 1,646 km².

 Total Land Requirement: = 24,043 + 1,646 = 25,689 km².

Challenges and Pathways

The Scale of the Challenge

Above estimation shows that even if India were to freeze its energy consumption at 2022 levels, the resources required to meet the Net Zero goal are staggering. The projected US $1.8 trillion investment for the transition equates to approximately 47% of India’s current GDP of US$ 3.8 trillion, underscoring the scale of the economic commitment involved. This investment excludes additional energy losses due to storage inefficiencies:
- Pump Hydro Storage Losses: Up to 30%.
- Battery Energy Storage Systems (BESS) Losses: Up to 10%.

Annual Investment Requirements

To maintain 2022 energy levels while meeting NZC commitments by 2070, India would need to invest approximately:
Annual Investment = US $1.8 trillion ÷ 45 years ≈ US $40 billion annually at 2024 prices.
This estimate assumes NO NET GROWTH in energy demand or growth served by efficiency gains, which is a highly conservative and unlikely scenario given India’s developmental ambitions.

Current Efforts and the Gap:

India is presently adding less than 20 GW of renewable energy capacity annually, with investments ranging from $12 to $15 billion per year. While this progress is notable, it is far below the required combined 38 GW of solar and wind capacity and $40 billion investment annually needed for next 45 years to achieve Net Zero Carbon (NZC) targets by 2070. Doubling these annual investments is essential merely to maintain current energy demands under Net Zero emissions. Meeting the anticipated growth in energy demand will necessitate even greater investments and a significantly accelerated deployment of renewable energy.

Key Challenges

1. Energy Storage Losses

Storing renewable energy to address intermittency involves significant losses:
- Pumped hydro systems lose 25–30% of energy.
- BESS systems lose 8–10% during charging/discharging.
These inefficiencies increase the required installed renewable energy capacity, compounding the challenges.

2. Land Acquisition

The land required for renewable energy installations and associated infrastructure remains a significant barrier:
- Solar and wind energy expansion requires ~25,689 km², around 1.4% of India’s agricultural land.
- Land conflicts and competing demands from housing, urbanisation and infrastructure development exacerbate the challenge.

3. Grid Modernization

India’s grid infrastructure must integrate large-scale renewables while minimizing transmission and distribution losses (currently ~10%). Investments in grid flexibility and smart grid technologies are crucial.

4. Financial Commitments

The estimated US $1.8 trillion investment represents a colossal financial burden, requiring international financing, private-sector participation, and innovative mechanisms like green bonds and carbon credits.

5. Energy Demand Growth

Freezing energy consumption at 2022 levels is neither practical nor sustainable for India’s growth trajectory. Energy efficiency measures and demand-side management must be prioritized to offset some of the growth.

6. Policy and Regulation

Bold reforms are needed to streamline project approvals, attract private investments, and incentivize energy storage and grid development.

 The Path Forward

To meet its Net Zero commitments, India must adopt a multifaceted approach. Key priorities include accelerating renewable energy deployment to 40–50 GW annually, enhancing energy efficiency across sectors, and investing in large-scale energy storage solutions like BESS and pumped hydro. Securing international funding, attracting private investments, and implementing robust policy measures such as carbon pricing and streamlined regulations are essential. Managing social and economic transitions, including reskilling coal-dependent workers and ensuring equitable access to renewable energy, will be critical for a sustainable and inclusive future.

Conclusion

Achieving Net Zero for India’s 2022 emissions of 2,514 million tons of CO₂ by 2070 requires systemic reforms across all sectors. Meeting this goal demands $40 billion in annual investments (at 2024 prices) and 38 GW of combined new solar and wind capacity yearly for next 45 years—far exceeding the current 20 GW capacity addition and $12–$15 billion annual investments. Bridging this gap necessitates accelerated renewable deployment, enhanced efficiency, and increased financial resources. Bold policy reforms, private-sector participation, and innovative financing, both domestic and external, are essential to overcome challenges like land acquisition, grid integration, and storage. With strategic planning, India can achieve ambitious climate goals and build a sustainable future.