Saving the planet from the coming climate havoc is among the most critical challenges of the century. To get over it, we have to be very creative. For example, we may extract energy from the atoms’ and molecules’ physical processes, waves, wind, sunlight, and even living beings. This prodigal idea has been proposed and successfully executed by a group of Cambridge researchers who fed a microprocessor with electrical energy from algae.

How about a battery of algae?

The researchers set out to study whether it was possible to extract electrical energy from the biological processes of algae. So they took non-toxic algae (synechocystis, better known as blue-green algae) and put it inside a box-shaped device filled with water. Then, they exposed it to the sun and watched as the algae began photosynthesizing. The extraction of electrical energy from the biological activity of plants and algae is known as “biophotovoltaic” energy.

The experts attached aluminum electrodes to the device through which modest electrical currents generated by the algae’s biological process could reach the microprocessor: an Arm Cortex M0+. The battery operated in a domestic environment, with natural light and temperature fluctuations. Six months after its startup, the algae continued to produce energy thanks to photosynthesis, and the data collected during that time were processed. Then, the study was published in Energy & Environmental Science.

Lead author of the paper, Dr. Paolo Bombelli, from the Department of Biochemistry at the University of Cambridge, said: “We were impressed with the consistency with which the system worked over a long period we thought it might stop after a few weeks, but it kept working,” in a news release.

According to New Scientist, the microprocessor was put through some basic calculations and simple tasks, consuming a mere 0.3 microwatts of electrical power. A conventional computer uses between 50 and 100 W per day, which means that if we think about powering our computer with energy from algae, we should first make sure that we have enough space at home to house the 333,000,000 batteries.

Back to the green (bluish) world

Although the battery could not produce significant amounts of power, experts consider this a good starting point for exploring sustainable energy options.

The battery the researchers developed is made of cheap and primarily recyclable materials. “The growing Internet of Things needs an increasing amount of power, and we believe it will need to come from systems that can generate power rather than just store it like batteries,” said Professor Christopher Howe of the University’s Department of Biochemistry. He is also a co-author of the paper. He added, “our photosynthetic device doesn’t run down like a battery because it continually uses light as a power source.”

The algae do not need assistance, maintenance, or food since the ecosystem provided to them is enough for them to live for an extended period. In addition, they can generate electricity even when not exposed to sunlight, as they process part of their food when there is no light, which continues to create an electrical current.

By 2035 there will be one trillion devices globally, and conventional lithium batteries will not be practical because demand cannot be met. So scientists are looking for new, portable ways to produce clean energy.

Biophotovoltaic energy could be one of the many alternatives to generate sustainable and environmentally friendly energy. Vast stretches of water could easily be home to energy-producing algae farms, floating solar panels, and offshore wind farms. The future of renewable energy is enormously promising, and the need for its implementation is urgent.