The renewables transition needs energy storage. Hydrogen is one of the most promising ways to do so — and Korean researchers have yet again made its production simpler, cheaper, and more efficient.
A team working with perovskite solar cells — a newer, fast-developing alternative to traditional silicon panels — has shown that these can be directly linked to devices that split water into hydrogen and oxygen, without the need for complex electronics in between. This approach makes it possible to turn sunlight straight into clean fuel in one step.
What’s New in This Study
Most solar-to-hydrogen systems rely on a separate power-conditioning unit to match the electricity from the solar panel to the needs of the electrolyser, the device that performs water splitting. These units add cost, complexity, and efficiency losses.
In this work, the researchers designed a single-junction perovskite cell made from CsPbBr₃, that naturally produces the right voltage and current to drive an electrolyser directly. By fine-tuning the cell’s properties, they achieved a system that runs without external power electronics and with minimal energy wasted as heat.
The result is a compact, integrated setup with a solar-to-hydrogen efficiency of 6.3%, which is competitive for a first-generation design of this type.
Why It Matters for the Energy Transition
Hydrogen is an essential part of most net-zero energy plans. It can store surplus renewable electricity, fuel clean transport, and serve as a feedstock for industries like steelmaking and fertiliser production. But green hydrogen taking off requires overcoming economic hurdles —that’s really where this new technology is helping.
By eliminating the extra power electronics, this new design reduces costs and makes systems easier to deploy, especially in places without advanced grid infrastructure. It also points toward lightweight, portable hydrogen generators that could work in remote areas, providing both clean fuel and energy storage without relying on a centralised power network.
The Path Ahead
While the device’s durability and large-scale manufacturing still need development, the concept is a significant proof-of-principle. Perovskites can be produced at low temperatures and on flexible surfaces, which unlocks low-cost mass production.
In the long term, refinements to both the solar cell and the electrolyser could raise efficiencies well beyond the current figure, making direct solar-to-hydrogen generation a competitive alternative to battery storage in many situations.
While solar technology constantly advances, creating energy more cost-efficiently, which can be stored as hydrogen, older, less-efficient solar technology is also effective in hydrogen production.
Source
Single junction CsPbBr₃ solar cell coupled with electrolyzer for solar water splitting, Nature Communications, 2025-07-30
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