Researchers from the University of Cambridge just ran a computer for six months using blue-green algae as a power source.
A type of cyanobacteria called Synechocystis sp. PCC 6803 produces oxygen through photosynthesis when taken under sunlight. It was sealed in a small container, made of aluminum and clear plastic.
The research was published in the journal Energy & Environmental Science.
The computer was placed on a windowsill at one of the researchers’ houses during the lockdown period and stayed there for six months, from February to August.
The computer ran in cycles of 45 minutes. It was used to calculate sums of consecutive integers to simulate a computational workload, which required 0.3 microwatts of power, and 15 minutes of standby, which required 0.24 microwatts.
It is possible that the bacteria produce electrons, which creates a current, or it creates conditions in which an aluminum anode in the container is corroded in a reaction that produces electrons.
More research is needed to take this to the next level. It can be used in rural areas of low and middle-income countries where a small amount of energy might be beneficial, such as environmental sensors or charging a mobile phone.
The bacteria create their food during photosynthesis, and the battery can continue producing power during periods of darkness.
The commercial applications can be expected in five years. They have also found other species of algae that create higher currents.