The big challenges standing in the way of a full frontal assault on petroleum by the clean energy industry are the cost of production and a dearth of ways to store the energy after its produced. But a team from Caltech’s Joint Center for Artificial Photosynthesis (JCAP) came up with new technology that could bridge that gap: an artificial leaf that mimics the process of photosynthesis by plants. The artificial leaf efficiently produces and chemically stores energy using nothing but the sun’s rays.
Artificial photosynthesis isn’t new, as the concept has existed since 1912. It has been researched ever since, but as with many renewable technologies, the cost of production has always been too high. Finding materials and creating a stable system have also been major challenges. After five years of work, JCAP has pioneered new technology that can bridge the gap, creating a process that’s not only efficient, but also stable and cost effective.
How does it work? According to Caltech:
“The new system consists of three main components: two electrodes—one photoanode and one photocathode—and a membrane. The photoanode uses sunlight to oxidize water molecules, generating protons and electrons as well as oxygen gas. The photocathode recombines the protons and electrons to form hydrogen gas. A key part of the JCAP design is the plastic membrane, which keeps the oxygen and hydrogen gases separate. If the two gases are allowed to mix and are accidentally ignited, an explosion can occur; the membrane lets the hydrogen fuel be separately collected under pressure and safely pushed into a pipeline.”
The demo setup produced by the researchers is capable of converting 10 percent of the energy it absorbs from the sun into energy stored in its chemical fuel – and can operate for more than 40 straight hours.
“This new system shatters all the combined safety, performance and stability records for artificial leaf technology by factors of five to 10 or more,” says JCAP director, Harry Atwater. “Our work shows that it is indeed possible to produce fuels from sunlight safely and efficiently in an integrated system with inexpensive components.” Of course, we still have work to do to extend the lifetime of the system and to develop methods for cost-effectively manufacturing full systems, both of which are in progress.”
Image and video via Caltech