New Scientist reports that photosynthesis research group the Howe Lab from Cambridge University was able to power a computer for six months using a colony of non-toxic photosynthetic algae called Synechocystis sealed within a small container about the size of an AA battery. The computer in question was obviously not a high-end gaming rig or even a low-end machine; it was an Arm Cortex-M0+ processor commonly found in Internet of Things devices. Nevertheless, the device was able to supply power from February to August 2021 as it sat on a windowsill, providing a continuous current across its anode and cathode. The Arm processor ran constant calculations to simulate real-world workloads and measured the current output from the device. There were no power interruptions during its six months of operations, and the cyanobacteria have continued to produce power since the experiment ended. The device can even produce power when it’s dark, possibly because the cyanobacteria continue to process surplus food. The team believes the power comes either from the cyanobacteria producing electrons, which creates a current, or they create conditions in which the aluminum anode in the container is corroded in a chemical reaction that produces electrons. While the experiment might not ultimately lead to algae-powered gaming PCs, it could have applications in the world of low-power IoT devices—there are expected to be one trillion IoT devices by 2035, and charging them using lithium-ion batteries would be impractical. The method could also be used to power environmental sensors or phone chargers. Researchers say algae-power is likely to be most useful in off-grid situations or remote locations.
