Three new 5-megawatt solar farms to be built in Tully will each be about twice as big at this installation at the former DeWitt town landfill. N. Scott Trimble (syracuse.com)

You could say the leaf is one of nature’s finest inventions, and for decades scientists have been at work trying to make a copy of it. The process plants go through is so unremarkable in its way that it doesn’t get much notice. It is called photosynthesis: with just sunlight, water and carbon dioxide they put together the chemical energy required to live.

Researchers have long wanted to put together an artificial version of this, something that can turn the sun into a usable fuel instead of merely making electricity. But most of these projects have come up against the same old issue. Sure, the systems functioned, but you needed batteries and all manner of external controllers and electronics to make them do so, which made for a costly and complicated affair. The technology was there, but not easy to scale.

Now researchers from Osaka Metropolitan University have put forward a new system that does away with some of that. This month they unveiled a device that will take in sunlight, water and carbon dioxide and make formic acid, a chemical for storing energy and as fuel. And it does so on its own, adapting to whatever the sun is doing without the need for outside control or batteries.[1]

It is a step forward in what has been one of renewable energy’s more intractable problems.

The Storage Problem

Take solar and wind power. In spite of the strides made in the last 20 years, both have a common flaw: they are only as good as the weather. When the sun goes down your panels are dark; a lull in the wind and the turbines don’t put out as much. You need storage to handle the excess, so the push for clean energy has in many ways become a contest over how to store it as much as to produce it. 

Batteries have become the go-to fix for this. You see governments underwriting their manufacture, companies pouring billions into new facilities and supply chains forming around lithium and nickel. But then again, a battery is hardly a perfect solution. They degrade over time, require large quantities of raw materials, and become difficult to deploy economically in industries that need vast amounts of energy for extended periods.

Researchers pursuing artificial photosynthesis are exploring a different approach. Instead of storing energy inside a battery, they store it directly in chemical fuel.[2]

Borrowing Nature’s Playbook

The concept behind artificial photosynthesis is surprisingly straightforward. Plants absorb sunlight and use that energy to transform water and carbon dioxide into energy-rich molecules. Scientists have spent decades trying to engineer devices capable of performing a similar process.

The Osaka Metropolitan University system does exactly that. Sunlight powers chemical reactions that convert water and carbon dioxide into formic acid, a compound that can serve as both a fuel and a hydrogen carrier. The key innovation is that the device regulates itself as sunlight conditions change throughout the day, eliminating the need for batteries and many of the electronic control systems used in previous designs.[1]

Around the same time, a separate research team led by Yale University demonstrated a standalone "artificial leaf" capable of producing methanol using only sunlight, water, and carbon dioxide.[3]

Together, the developments suggest that artificial photosynthesis is gradually moving from a laboratory curiosity toward a more practical technology platform.

Why Researchers Care

The significance of artificial photosynthesis is not that it generates electricity, but rather that it creates fuel, which is the stored equivalent. That distinction matters because some sectors of the global economy remain difficult to electrify. Commercial aviation, maritime shipping, chemical manufacturing, and heavy industry require dense, transportable energy sources that batteries often struggle to provide economically.

Fuel ultimately remains the dominant solution, and artificial photosynthesis offers a potential pathway to producing those fuels using sunlight and captured carbon dioxide. Researchers argue that the technology could eventually provide a way to store renewable energy in a form that is easier to transport and use over long periods of time.[4]

The idea has attracted growing interest from scientists and policymakers because it addresses two challenges simultaneously. Firstly by storing intermittent renewable energy, and secondly recycling carbon dioxide into useful products.[5]

What Comes Next

Energy history is full of technologies that performed well in controlled experiments but struggled once manufacturing costs, infrastructure requirements, and market competition entered the equation. Researchers still need to improve efficiency, durability, and scalability before the technology can move beyond small-scale demonstrations.[4]

For now, artificial photosynthesis remains experimental. But recent developments suggest researchers are making progress on one of renewable energy's most difficult problems. Generating electricity is only part of the challenge. Storing it, transporting it, and using it in energy-intensive industries may prove just as important.

Whether artificial photosynthesis becomes a major energy technology remains to be seen. What is clear is that scientists are getting closer to turning sunlight directly into a usable fuel, a goal that, until recently, seemed far more theoretical than practical.

References:

[1] Osaka Metropolitan University. "Scientists Built a Battery-Free Device That Turns Sunlight Into Fuel." ScienceDaily, June 11, 2026. https://www.sciencedaily.com/releases/2026/06/260611024601.htm

[2] Wang, Qian, and Chanon Pornrungroj. "Artificial Photosynthetic Processes Using Carbon Dioxide, Water and Sunlight: Can They Power a Sustainable Future?" Chemical Science, 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12498249/

[3] Yale University. "Growing a New 'Leaf' That Harnesses Sun, Water and CO₂ to Make Liquid Fuel." Yale News, June 4, 2026. https://news.yale.edu/2026/06/04/growing-new-leaf-harnesses-sun-water-and-co2-make-liquid-fuel

[4] Inorganic Chemistry Communications. "Artificial Photosynthesis: Emerging Strategies for Solar-to-Fuel Conversion." June 2026. https://www.sciencedirect.com/science/article/pii/S1387700326003692

[5] Times of India. "Scientists Build an Artificial Leaf That Turns Sunlight, Water and CO₂ Into Fuel Without a Battery." June 2026. https://timesofindia.indiatimes.com/science/scientists-build-an-artificial-leaf-that-turns-sunlight-water-and-co-into-fuel-without-a-battery/articleshow/131678723.cms