It may seem odd that algae (seaweed) can power an electronic device. Cambridge researchers recently powered a microprocessor continuously for over a year using a common type of blue-green algae (Synechocystis), providing them with light and water. They suggest that algae might be able to provide power to small devices.

Here’s how it works:

Some advantages of algae, according to the researchers:

● Because algae use light as their energy source to produce a tiny electrical current, they don’t “run down,” like batteries.

● Systems for using algae to produce current can be made from “common, inexpensive and largely recyclable materials” according to the researchers, Paulo Bombelli et al., who developed the test device. Its main use is seen to be in off-grid or remote places where only a small amount of power is needed anyway.

● The researchers note that, as the number of small devices in the world (the Internet of Things) approaches the trillion mark by 2035, the demand for lithium will be three times the supply, to say nothing environment damage done by batteries using made using hazardous materials.

“The growing Internet of Things needs an increasing amount of power, and we think this will have to come from systems that can generate energy, rather than simply store it like batteries,” said Professor Christopher Howe in the University of Cambridge’s Department of Biochemistry, joint senior author of the paper…

In the experiment, the device was used to power an Arm Cortex M0+, which is a microprocessor used widely in Internet of Things devices. It operated in a domestic environment and semi-outdoor conditions under natural light and associated temperature fluctuations, and after six months of continuous power production the results were submitted for publication.

Jacqueline Garget/Research news, “Algae-powered computing: scientists create reliable and renewable biological photovoltaic cell” at University of Cambridge (May 12, 2022)

For now, of course, it is only a demonstration project:

The cyanobacteria system isn’t powerful enough yet to run all devices. A desktop computer would need 333,000,000 algae batteries to work normally, reports James Vincent for The Verge. But the authors say the system could be scaled up, though knowing how far would require more research. p1 “Putting one on your roof isn’t going to provide the power supply for your house at this stage. There’s quite a bit more to do on that front,” Howe tells New Scientist. “But [it could work] in rural areas of low and middle income countries, for example, in applications where a small amount of power might be very useful, such as environmental sensors or charging a mobile phone.”

Margaret Osborne, “Researchers Use Algae to Power a Computer for Months” at Smithsonian Magazine (May 17, 2022) The paper requires a fee or subscription.

Interestingly, the algae continue to produce a current in the darkness. The researchers suspect that algae process some of their food in the dark; thus, the power supply is not interrupted.

Incidentally, algae and other marine plants provide an estimated 50% of all the oxygen we breathe via photosynthesis.

You may also wish to read:

Could carbon computing make computers more environment friendly? As a key component of life forms, carbon is abundant and energy efficient. Carbon-based computing uses vastly less energy than silicon-based, just as a human brain, with as many connections as the internet, uses much less energy. (November 2020)