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Solar panels are an extremely important tool for generating clean and sustainable energy. Its popularity and effectiveness are increasing day by day, but there is a problem. They only work half the day.

And in some areas of the world where daylight availability fluctuates dramatically, such as the Nordic countries, these panels can be ineffective not only during certain parts of the day, but also for much of the year. As a solution, the solar panel.

Solar panels offer a way to capture energy at night. Together with conventional solar panels, solar panels create a sustainable source of energy that can be used all day and year round.

New research has developed a system to optimize it.

A team of researchers from Stanford University and the Technion-Israel Institute of Technology theoretically optimized the existing infrastructure for solar panels: thermoelectric generators.

These generators create an electrical voltage by converting the temperature differences between a heat source (for example, ambient air temperature at night) and a specially cooled surface of the generator.

While these generators already exist, the study authors argue that they fall short of their potential and are not sustainable options for off-grid power generation.

Lingling Fan, the study’s first author and doctoral candidate in electrical engineering at Stanford University, says his study aims to optimize this existing design.

We are working to develop a generation of high-performance, sustainable lighting that can provide everyone – including those in rural and developing areas – with access to reliable and sustainable sources of lighting energy at low cost.

Lingling fan.

Fan says that a modular power system like this could even be used to convert waste heat from cars into usable energy.

Despite their linguistic similarity to the common solar panel, solar panels do not look like conventional photovoltaic panels.

The team experimented with simulating different improvements, such as the way heat circulates in the system and the use of commercially available thermoelectric materials to improve the efficiency of the system in using its energy.

Wei Li, co-author of the study and postdoctoral fellow at Stanford, says one of the most important changes they simulated was the use of a material to better control how the generator vented the excess heat.

One of the most important innovations was the design of a selective emitter attached to the cold side of the device. This optimizes the radiant cooling process so that the power generator can remove excess heat more efficiently.

Wei Li.

After analyzing these simulated improvements, the team found that their design was capable of generating 2.2 watts of power per square meter (2 W / m2), what is 120 times more energy than previous experimental models they were able to achieve it, write the authors.

Authors also that a system like this could even be worn during the day, creating an overlay of energy production with traditional solar panels.

That being said, there is a difference between the simulated results and how this system might actually work.

However, the authors argue that this design demonstrates that the system is theoretically feasible using commercially available technology – we don’t have to wait for new materials or innovations. In the future, this off-grid solution could be used to provide sustainable energy and essential electricity services.

More information: www.osapublishing.org