Scientists fed the computer with energy from blue-green algae for six months

Researchers from the University of Cambridge managed to run a computer for six months using blue-green algae as an energy source. The computer worked in cycles of 45 minutes. It was used to calculate sums of consecutive integers to simulate a compute load that required 0.3 microwatts of power and 15 minutes of idle time that required 0.24 microwatts.