Solar panels that use bacteria to generate electricity

A new generation of solar panels that use bacteria can generate electricity even with cloudy skies. The renewable energies are here to stay but still, have their drawbacks. In the case of plates with photovoltaic cells, their viability is compromised in northern areas with little solar radiation.

In addition, although its production costs have fallen and its efficiency has increased greatly in recent years, it is still difficult to find, on average, percentages of conversion of light into energy greater than 25%.

Currently, the main material used is silicon, but that may change in the not too distant future. And it will not be for any material of the latest generation such as graphene, but for one of the oldest forms of life on our planet: bacteria. Specifically, a species with a bad reputation such as E. coli, known for the digestive disorders it can cause.

The new technology is the result of research by a team of scientists from the University of British Columbia (Canada), who have opted for a biogenic approach, that is, using living organisms to generate electricity. For this, they have been based on the dyes that bacteria use to carry out photosynthesis processes.

E. coli bacteria

In previous investigations, it had been tried to extract the dyes to apply them in the solar panels, but the process was expensive and toxic. So scientists have looked for another approach that is based on genetic engineering. Instead of extracting the dyes, they have programmed E. coli bacteria to produce a greater amount of lycopene, the same substance that is responsible for the red color of fruits and vegetables.

After impregnating the culture of bacteria with a mineral that exerted as a semiconductor, they proceeded to spread a layer of the mixture on a glass surface. Later, they found that bacteria were capable of generating electricity even in conditions of very low luminosity, such as the one that reaches us on cloudy days.

The results are extremely encouraging, as they have doubled the amount of electricity generated, from the 0.362 milliamperes achieved in previous experiments to 0.686 milliamps per square centimeter. It is the largest electric current generated by a  biogenic photovoltaic cell, according to Vikramaditya Yadav, the scientist who has spearheaded the project.

Although it is still early to calculate accurately the savings that the new technology can bring, Yadav assures that production would be cheap and sustainable. In addition, the applications of these solar panels from live bacteria could be extended to mining or underwater exploration.

Biosynthesis, green chemistry

Vikramaditya Yadav is one of the pioneers of a new field of research that could have repercussions in numerous areas, not only energy but also pharmaceutical. It is a field that Yadav has baptized as "biosynthetic".

In an article published a few years ago in the journal ACS, the Indian scientist pointed to the diminishing returns in the investigation of new medicines. The new drugs need up to ten years of development and investments of more than one billion dollars. It was time to try new approaches and integrate the benefits of genetic research.

Fundamentally, the biosynthetic is to discover and synthesize bioactive molecules, expanding the spectrum of chemical investigations. This process, which is called "metabolic engineering", allows the synthesis of new drugs of interest to industry and medicine, through the alteration of genes or the metabolic fluxes that occur in microorganisms.