Next week, international leaders and scientists are meeting in Paris to figure out how to lower the world's reliance on fossil fuels – but one of the key challenges they'll face is finding clean and highly efficient energy sources to take their place.
One candidate for the job? Green slime. Or, technically, blue-green slime. Scientists in Canada have used blue-green algae to energise a new kind of power cell that harnesses an electrical charge from the photosynthesis and respiration of cyanobacteria, which are the microorganisms that make up blue-green algae.
"Both photosynthesis and respiration, which take place in plant cells, involve electron transfer chains. By trapping the electrons released by blue-green algae during photosynthesis and respiration, we can harness the electrical energy they produce naturally," said engineer Muthukumaran Packirisamy from Concordia University in Montreal.
The photosynthetic power cell consists of an anode, cathode, and proton exchange membrane. The blue-green algae are placed in the anode chamber, and as they undergo photosynthesis, they release electrons onto the electrode surface. With an external load attached to the cell, it's possible to extract the electrons and harness power from the device.
From a natural resources point of view, blue-green algae are a fantastic choice to help take the burden off diminishing fossil fuels cyanobacteria are one of the most prosperous microorganisms on Earth. Plus, unlike other renewable energy sources like solar power and wind power, their efficiency doesn't vary with changes in the weather.
"By taking advantage of a process that is constantly occurring all over the world, we've created a new and scalable technology that could lead to cheaper ways of generating carbon-free energy," said Packirisamy.
It's still early days for the technology, with the researchers noting that they have a lot of work to do in terms of scaling the power cell to make the concept commercially viable.
So far, they've measured open-circuit voltage as high as 993 millivolts and obtained a peak power of 175.37 microwatts, as detailed in their published findings in Technology. If they can expand on these initial achievements, the researchers hope the system will one day be powerful enough to run the electronic devices we use everyday – in addition to helping humanity cut down greenhouse gas emissions.
"In five years, this will be able to power your smart phone," Packirisamy told Chris Arsenault at Reuters. Take that, lithium-ion.