Key facts
- A new battery-free artificial photosynthesis system has been developed by researchers at Osaka Metropolitan University.
- The system converts sunlight, water, and carbon dioxide into formic acid, a liquid fuel and energy-storage chemical.
- Unlike many existing systems, it does not require batteries or electronic controllers for stable operation.
- It utilizes a self-regulating chemical component that responds to changing sunlight conditions.
- The technology aims to simplify solar fuel production, reduce costs, and enhance practicality for real-world deployment.
- The system was tested outside laboratory settings and demonstrated its ability to power an installation at Expo 2025 Osaka.
Scientists at Osaka Metropolitan University have developed a novel battery-free artificial photosynthesis system capable of continuously converting sunlight, water, and carbon dioxide into formic acid, a liquid fuel. This innovation aims to mimic the natural process plants use to create energy-rich compounds, offering a more practical and cost-effective approach to solar fuel production.
Traditional artificial photosynthesis systems often rely on photovoltaic panels to generate electricity, which then powers electrolyzers to convert carbon dioxide and water into fuels. However, the fluctuating nature of solar power necessitates the use of batteries or complex electronic controls to maintain stable operation. The Osaka team's approach bypasses these requirements by redesigning the electrolyzer with a self-regulating chemical component. This "chemical MPPT system" automatically adjusts to varying sunlight conditions, allowing for continuous fuel production without conventional battery-based mechanisms.
The system's design prioritizes simplicity and cost reduction by eliminating the need for expensive and redundant electronic maximum-power-point tracking systems. It powers its low-energy components, including piezoelectric pumps and a microprocessor, directly from solar panels via a buck-boost DC/DC converter. The primary output is formic acid, a carbon-based liquid that can store hydrogen stably and is produced by combining carbon dioxide and water through electrochemical reactions. Researchers utilized a specialized three-compartment electrolyzer for stand-alone, unmanned operation.