Air pollution cut India's solar power output by 9.6% in 2023, study says

📌 Summary:

• New study in Nature Sustainability finds aerosols cut India's solar power generation by 9.6% in 2023 — about 15 terawatt-hours (TWh) lost
• Global average loss in 2023 was 5.8%; India among the world's worst-affected, with the heaviest losses in heavily polluted north
• Multi-year picture (2017–2023): pollution-related losses from existing solar installations averaged 74 TWh per year — roughly one-third of the electricity produced annually by NEW solar capacity added each year
• Methodology: world's first facility-level database of solar PV generation/losses covering 1,40,000 installations; combined with satellite data, atmospheric data, and machine learning
• Aerosols are fine sulphate and carbon particles; chief human sources are coal plants, road transport vehicles, and industries
• Smog (aerosols + gases) directly cuts sunlight reaching panels, undermining a key replacement for coal
• China (largest solar producer, 793.5 TWh in 2023) lost 61.3 TWh (7.7% of total) — bigger absolute loss but smaller fractional loss than India
• China cut pollution-related solar loss by ~1.4%/yr from 2013–2023 EVEN WHILE expanding coal — by retrofitting coal plants with flue-gas desulphurisation (FGD), which removes SO₂ and particulates
• India's aerosol-induced solar losses STAYED FLAT from 2013–2023 (no improvement)
• India in 2025 WEAKENED its FGD target — restricting mandatory FGD only to coal plants near major cities and case-by-case to critically polluted areas
• Policy implication: air pollution and renewable energy are intertwined — without aggressive FGD rollout, India's renewable energy investment yields lower returns

🎯 UPSC Relevance: GS3 — Environment (Pollution / Renewable Energy / Climate Change); GS3 Economy (Infrastructure-Energy); GS3 S&T (atmospheric science); SDG-7 (Affordable Clean Energy); SDG-3 (Air-Quality–Health); links air quality policy to clean-energy returns

📝 Prelims Facts:

• Journal: Nature Sustainability
• India's 2023 solar loss due to aerosols: 9.6% / ~15 TWh
• Global average loss: 5.8%
• China's 2023 solar generation: 793.5 TWh; loss = 61.3 TWh (7.7%)
• Annual pollution-induced loss from existing Indian solar installations (2017–2023 average): 74 TWh
• Key mitigation tech: Flue-Gas Desulphurisation (FGD) — removes SO₂ from flue gas
• India weakened FGD installation mandate in 2025

🔑 Key Term: Flue-Gas Desulphurisation (FGD) — pollution-control technology installed in coal-fired power plants that removes sulphur dioxide from exhaust flue gases before release; reduces acid rain, particulate haze, and (per this study) aerosol-blocking of solar generation downstream.