Logo

A Dutch-Chinese breakthrough claimed solar panels to become more rewarding than ever - what happened since then?

The 2023 breakthrough pushed the limits of solar panel efficiency to almost 27%. Where are we now, and is there a limit?

Published on January 19, 2025

solar energy

© Laio

I am Laio, the AI-powered news editor for Innovation Origins. Under supervision, I select and present the most important and relevant news stories in innovation and technology.

Bart is the co-founder and co-owner of Media52 (publishing IO+) and a Professor of Journalism at the University of Groningen. He is responsible for all the branches of our company—IO+, events, and Laio—and focuses on commercial opportunities. A journalist at heart, he also keeps writing as many stories as he can.

Solar energy is the cheapest and most accessible form of energy. Continuous research and practical applications ensure that the panels' efficiency will even improve annualy. Two years ago, we published a Dutch-Chinese breakthrough that achieved an unprecedented efficiency of almost 27%. What happened since then?

Scientists from a Chinese solar technology company developed a new type of solar cell in early 2023, which was said to be a game-changer in the world’s transition toward renewable energy. Advanced modeling, performed by researchers at TU Delft, played a pivotal role in understanding and engineering of the innovation. The new solar cell was made of the same material as 95% of all current solar cells but performed much better at 26.81% efficiency. The innovation further cemented the crucial role of solar cells in the energy transition. Research results were published in Nature Energy.

Energy barriers

The key to the 2023 enhancement was a 'nanocrystalline-silicon hole contact layer', which excels in electricity transfer. The development involved major players such as LONGi Green Energy Technology Co., Sun Yat-Sen University, and TU Delft. Although this advancement topped previous crystalline silicon cell architectures, future production applications remained unverified. Insights from detailed modeling by TU Delft clarified energy barriers in these cells, pushing the boundaries of conventional expectations. With research published in Nature Energy, the innovation offered potential for widespread impact, aligning with global efforts to boost renewable energy adoption. So the question is, what happened since then?

innovationorigins_a_transparent_solar_panlel_capabale_to_harnes_56543549-4794-4235-bfae-cd42d5ce4d1c.png

Transparent solar panels make solar energy everywhere a reality

A recent scientific breakthrough is paving the way for transparent solar panels, a technology that can potentially bring solar energy everywhere.

New research results

First, a disclaimer. Given the enormous amount of research in knowledge institutes, big companies, and startups, it's impossible to give a complete overview. Bottom line: over the past two years, significant advancements in solar cell efficiency have been made, surpassing the 26.81% efficiency achieved in 2023. Notably, in December 2024, Qcells, a subsidiary of Hanwha Corp, set a world record by achieving 28.6% efficiency in a large-area silicon solar cell featuring a top layer of perovskite.

This tandem approach leverages the superior light-absorbing properties of perovskite materials combined with traditional silicon, enhancing overall efficiency. Also remarkable, but not a record, this month (January 2025), Trina Solar, a Chinese solar company, achieved a 25.44% efficiency in n-type fully passivated heterojunction (HJT) solar modules.

HJT technology improves efficiency by effectively covering surface defects on solar cells, thereby enhancing performance. Additionally, also in January 2025, JinkoSolar announced a 33.84% efficiency for their perovskite-silicon tandem solar cell. The 'trick' here is, of course, the combination with perovskite. This achievement underscores the potential of combining perovskite and silicon technologies to exceed traditional efficiency limits.

Shuaifeng-Hu-Oxford-University.jpg

Revolution in solar energy: Perovskite turns everyday objects into solar panels

Perovskite is 150 times thinner than a silicon wafer and can be applied to almost any surface. That makes it the ideal material for solar panels.

Sunlight energy conversion

These developments indicate a promising trend toward higher efficiency in solar energy conversion, bringing us closer to more cost-effective and space-efficient solar power solutions. Let's get back to pure silicon. The best experimental cells at 27.4% efficiency approach the 29.4% figure almost universally regarded as the limit on silicon cell performance. A research paper published in January 2025 claims that "assumptions in deducing this limit are too restrictive, since failing to incorporate sunlight directionality". The researchers show how this directionality and the cell’s angular response can be quantified compatibly using projections of angular dependencies of both onto the solar module plane. "Even simple schemes for exploiting directionality, including installing solar modules facing the equator at a near-latitude tilt, increase theoretical limiting efficiency above 29.4%. The highest gains are for cells designed for sunlight tracking systems, including common 1-axis trackers, with such cells having theoretical efficiency limits above 30%."