New Solar Cells Keep Collecting Power Even On Cloudy Days

As useful as solar panels are, one of the most common issues they deal with is lack of sunlight on cloudy days. That could soon cease to be as much of a problem, thanks to researchers from the University of British Columbia who have managed to make solar cells that function even under low light conditions.

Researchers managed to construct a solar cell based around the bacteria, which gave this cells the ability to operate efficiently in a variety of lighting conditions.

Creating Biogenic Solar Cells

Solar cells are what solar panels are constructed out of, the building blocks of the solar power collection unit. The actual solar cells are what are responsible for capturing light and converting it into electrical currents.

There have been previous projects that examined the potential use of solar cells based off of actual living matter. These projects are known as biogenic cells, and they work by mimicking the process of photosynthesis found in plants, nature’s way of extracting energy from sunlight.

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Photosynthesis happens in plants thanks to an organelle within plant cells called a chloroplast, which has a pigment known as chlorophyll. Chlorophyll and other pigments absorb light within certain parts of the electromagnetic spectrum. Visible radiation (light) is simply the part of the electromagnetic spectrum that humans can see, and the energy in these wavelengths can be captured by certain pigments. It isn’t just the cells of plants that can do this, however. Certain bacteria also have dyes that can absorb energy from light. Techniques were invented to use genetically modified bacteria and extract their light-sensitive dyes, but these were expensive and difficult processes to carry out.

The UBC team utilized a simpler approach involving the use of a strain of genetically engineered E. coli that create a chemical substance called lycopene. Lycopene is one of the chemicals responsible for giving tomatoes there red/orange color, and the chemical is also an efficient absorber of sunlight. The engineered E. coli strains were treated with a mineral that allowed them to function as a semiconductor, and the treated strains were spread across a glass surface. This improvises solar cell performed well in tasks, achieving a current density of approximately 0.69 milligrams per square meter, which is approximately double the performance of previous biogenic cells.

Applications And Enhancements

The technology would be extremely beneficial to areas like Northern Europe and Canada that frequently have cloudy skies. Right now, solar energy is often only a wise economical investment for people who live in more middle latitudes. The technology could also, potentially be used in other low light conditions, like under the ocean.

Vikramaditya Yadav, professor from UBC’s department of biological and chemical engineering lead the project, and stated that the project was a huge step forward in making solar energy more widely available and economical. Said Yadav:

We recorded the highest current density for a biogenic solar cell. These hybrid materials that we are developing can be manufactured economically and sustainably, and, with sufficient optimization, could perform at comparable efficiencies as conventional solar cells.

Yadav and his team are excited about the project, as they believe the process to be much more efficient and substantially cheaper with costs estimated at somewhere around 1/10 of the current cost of creating biogenic cells. While the bacteria powered solar cells show substantial possibility, there’s still much work to be done to make the technology a viable method of collecting energy. Currently, the bacteria used in the process die off after a certain amount of time, meaning that the researchers need to create more batches of the bacteria/mineral concoction to keep producing the dye. If the research team can figure out a way to keep the bacteria alive, they would produce the dye indefinitely.

Scientists who work on photovoltaic systems and solar cells are constantly looking for ways to overcome the current limitations of solar power technology, looking for ways to increase the efficiency of conversion from energy to electricity, finding cheaper and better ways to store energy, and finding new ways to convert solar energy into different forms of energy.

Solar Panels That Work In The Rain And Perovskite Solar Cells

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Chinese scientists have managed to develop solar panels that produce electricity during rainstorms, using the rainwater itself. The researchers found that if the bottom side of the solar cell was covered with a thin layer of graphene, the positively charged ions in the raindrops would interact with it and produce electricity. This strategy makes use of a chemical process known as the Lewis acid-base interaction, and when the positive and negative ions (and dissolved salts) in raindrops come into contact with the grenadine, it creates a temporary capacitor as the positive ions of elements like sodium and calcium cause electrical currents. Combining the strategy with the low light capable bacteria based solar cells could dramatically enhance the amount of energy that solar panels produce on rainy days.

The past few months have witnessed notable advancements in solar power technology. Just recently a team of researchers from the University of Surrey succeeded in creating an inverted perovskite solar cell with the highest ever recorded performance. Perovskite cells are frequently viewed as the next logical step for solar cells, as they are capable of achieving similar power conversion efficiency as the current crystalline silicon based solar cells, yet at a substantially lower cost than said silicon based cells.

The research team from University of Surrey were able to discern a method of reducing energy and efficiency lost to a process known as non-radiative recombination. The team was able to increase the voltage of the inverted perovskite cells to around 100 millivolts, which meant that the cells were able to reach a limit of about 1.21 volts without any sacrifice to the quality of the electrical current flowing through a device or to the solar cell.