https://www.techspot.com/news/94603-res ... g-but.html
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.