Why in the News?

Amid rising energy demands and climate concerns, experts are calling for a shift toward more efficient and scalable green technologies beyond conventional silicon photovoltaics and green hydrogen.

What’s in Today’s Article?

• Green Technologies (Introduction, Limitations, Rethinking Approach, Policy & Investment Implications)

Introduction

• The world is racing to meet its climate commitments amid the growing urgency of energy self-sufficiency, carbon emission reduction, and geopolitical uncertainty.
• While green technologies like silicon photovoltaics and green hydrogen have catalysed a global energy transition, they are no longer sufficient in their current forms.
• The future demands not just more renewable deployment, but smarter, more efficient, diverse, and scalable green technologies that better serve a resource-constrained world.

Limitations of Current Green Technologies

• Silicon Photovoltaics: Dominant Yet Inefficient
  • Invented in 1954 by Bell Labs, silicon photovoltaics (PV) have become the backbone of renewable energy worldwide. However, their limitations are becoming apparent:

• Typical efficiencies range from 15% to 21%, with lower actual field performance.
• Land-use intensity is high due to low energy conversion rates; a doubling of efficiency could halve the land required.
• Over 80% of silicon solar panels come from China, raising strategic and supply chain concerns.

• India, with ~6 GW of production capacity, is expanding its silicon PV output, but must also prepare to leapfrog toward next-generation solar technologies like gallium arsenide thin-film cells, which have demonstrated up to 47% efficiency in labs.

• The “Green” in Green Hydrogen is Relative
  • Green hydrogen, produced by electrolysis using renewable energy, is a promising clean fuel. However, it suffers from key drawbacks:

• Energy inefficiency: Electrolysis consumes more energy than the energy value of the hydrogen it produces.
• Storage and transportation challenges due to hydrogen’s low density and leakage issues.
• Conversion losses in creating and later separating hydrogen from green ammonia or methanol.

• Therefore, while green hydrogen is technically clean, its overall lifecycle efficiency is poor, especially when powered by low-efficiency PV systems.

Rethinking Fuel Production and CO₂ Utilisation

• To overcome these hurdles, researchers are exploring Artificial Photosynthesis (APS), mimicking plant-based CO₂ recycling to produce fuels like green methanol and green ammonia directly from sunlight, water, and atmospheric gases.
• While APS is currently confined to lab research, it represents a breakthrough pathway for truly sustainable fuel production.
• Meanwhile, Europe is pushing ahead with Renewable Fuels of Non-Biological Origin (RFNBOs), which avoid biomass and use pure renewable inputs.
• India, too, must pivot toward such futuristic innovations to reduce its 85% dependence on imported energy, which includes oil, coal, and natural gas.

Land Scarcity and the Efficiency Imperative

• Land scarcity is becoming a significant constraint:

• Urbanisation and biodiversity conservation limit the availability of large tracts for solar installations.
• With rising CO₂ concentrations (from 350 ppm in 1990 to 425 ppm in 2025), current green technologies are not scaling fast enough to reverse climate trends.

• Thus, doubling down on high-efficiency technologies becomes essential, not just to generate more power per square metre, but also to enable complementary decarbonisation solutions like green hydrogen and RFNBOs to succeed.

Policy and Investment Implications

• Governments must now shift from deployment to diversified innovation. India’s energy roadmap should include:

• Increased R&D spending on next-gen energy systems
• Public-private partnerships to accelerate commercialisation
• Strategic support for deep-tech innovations like APS and RFNBO
• Redesign of subsidies and incentives to favour higher efficiency, land-saving, and lifecycle-optimised technologies

• As geopolitical instability threatens global supply chains, energy independence through innovation is no longer optional; it is urgent and essential.