The landscape is further complicated by new demands such as the widespread production of green hydrogen, touted as a key enabler of deep decarbonisation. Today’s solar panel technologies not only affect the quantity of clean electricity generated but directly shape the potential and credibility of downstream solutions like green hydrogen, green ammonia, and green methanol. As nations grapple with land constraints, rising carbon dioxide levels, and the urgency of energy self-sufficiency, the imperative grows not just to deploy more renewables but to invest in smarter, more efficient, and more diverse energy innovation.

Silicon photovoltaics

The widely used solar panels, or silicon photovoltaics, were originally invented by researchers at Bell Laboratories in the U.S. in 1954 and first deployed on satellites so they could generate power in space. From there, they slowly entered other industries over time until, in the last few decades, their adoption exploded worldwide.

Current solar panels generally have a reported efficiency of around 18-21% and an in-field efficiency of 15-18%. In the last 15 years or so, around 80% of the supply of solar panels has been from China. In India, the production of silicon solar cells has reached around 6 GW and is expected to increase further in the coming years.

At this juncture, as the world prepares to invest more in solar power even as the ability to harness it has become a strategic ability, an important question has arisen: should we continue to adopt silicon solar panels even though superior, more efficient technologies have become available?

The best research-based solar cell efficiency chart has been regularly updated from 1976 for a broad range of photovoltaic technologies. There are many, with the maximum efficiency of around 47% being achieved by single junction gallium arsenide thin-film technology. Many of these photovoltaic setups have already been demonstrated at a high level and are ready to be commercialised.

Because silicon solar panels’ efficiency is below 18%, they need to have greater area exposed to the sun than panels of higher efficiency. When the efficiency doubles, the required collection area halves.

Land area is becoming a rarer commodity: countries are urbanising rapidly even as increasing environmental consciousness, driven by the pressures of climate mitigation, render green spaces too valuable to be diverted for solar power plants.

Silicon photovoltaics are also slow runners in the world’s race to catch up with its own growing energy demand. While 4.45 TWh of renewable energy generation capacity had been installed until the end of 2024, the CO2 concentration in the atmosphere has continued to increase — from 350 ppm in 1990 to around 425 ppm in 2025 — implying energy demand is only increasing faster.

Costs of green hydrogen

The widespread adoption of silicon photovoltaics also has implications for the ‘greenness’ of green hydrogen, among other fuels. Hydrogen as a fuel can be produced by using a large electric current to break apart water molecules (H2O). If this current comes from a renewable energy source, the resulting hydrogen is called green hydrogen.

Green hydrogen is environment friendly and doesn’t emit any greenhouse gases when it is combusted. However, the current electrolysis technologies available consume more energy to produce green hydrogen than its energy value in use. The yet other costs hydrogen imposes include that of its storage and transportation, which are very difficult because of the element’s extremely low density, which causes it to leak easily.

As alternatives, experts have proposed infusing the green hydrogen into molecules like green ammonia (NH3) and green methanol (CH3OH), which are easier to transport, before extracting the green hydrogen at the destination.

However, using green hydrogen to produce green ammonia or methanol by conventional catalysis methods, followed by stripping hydrogen out of those molecules, also requires a significant amount of energy.

Thus, at the first step itself — the act of generating renewable energy from silicon photovoltaics — there is a compromise on efficiency (that is, by not adopting more efficient solar power technologies). And in the subsequent steps, energy is consumed for electrolysis, storage or conversation, transport, and finally utilisation. As a result, the greenness of green hydrogen should not be taken at face value.

CO2 recycling

One alternative is to produce green methanol or ammonia directly from water, sunlight, and carbon dioxide or nitrogen, respectively. The plants in our gardens are already doing this everyday in a process called photosynthesis. Similarly, some scientists are working on a process called artificial photosynthesis, or APS. Currently, while APS technologies are restricted to the lab bench, some bright spots indicate they have a promising future.

As the world’s various net-zero targets come into view, it’s important to develop and perfect diverse technologies, rather than just a few, so that it has the best shot of achieving carbon-neutral economies.

Europe is already working on ‘Renewable Fuels of Non-Biological Origin’, or RFNBO, which is the production of fuels with renewable energy and resources and without biomass. India should also work on such futuristic solutions to become energy independent, from its current position of importing nearly 85% of different forms of energy resources (including oil, coal, and natural gas) from other countries.

As geopolitical conflicts proliferate and the supply of energy is increasingly disrupted, achieving energy self-sufficiency is paramount. As such the Government of India should consider spending more on research, innovation, and technology development with help from the private sector.

Prevention is better than cure. Spending ₹1 crore on preventing pollution today will save us from having to spend several crore in the future on damage control. While green hydrogen and silicon photovoltaics are good technologies, the world already needs better, that is, more efficient, more practicable, more economic, and more diverse solutions.

Reference : https://epaper.thehindu.com/ccidist-ws/th/th_kozhikode/issues/142064/OPS/G97EN6EJ5.1+GICEN6FU5.1.html

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