How to benefit from solar energy at night?

How to benefit from solar energy at night?

A research team from Stanford University was able to generate large amounts of electrical energy at night using solar energy cells.

Since people have realized the dangers of fossil fuels and the damages resulting from them in terms of air pollution, climate change, the decline in human health, and the spread of diseases, it has become imperative to change the direction toward clean or renewable energy, which is safer and less expensive.

There are many types of this energy, including wind energy, solar energy, hydroelectricity, and others. Scientists and researchers are working to develop these energies and make the most of them. In this regard, a group of researchers at Stanford University, California, USA, was able to enhance the productivity of solar cells, so that they can produce larger amounts of electrical energy at night. The study was published in the Applied Physics Letters on April 5. April 2022.

Solar Panels

The solar panel consists of a group of small cells called solar cells. These cells are exposed to the sun and work to convert light energy into electricity. A cell generates more electricity the more light it receives. The world's attention has turned to these panels in recent years, as they are saving on the one hand and a clean source of energy on the other hand, which makes them an amazing opportunity to save the world from the problems of climate change caused by fossil fuels, as space agencies use them in designing spacecraft and directing them towards the sun, to get the amount of solar energy to generate electricity.

Taking advantage of solar energy at night 

Solar cells can produce between 100 to 200 watts / square meter during sunrise, However, productivity drops significantly at night to just 50 megawatts per square meter. Because of this significant difference, researchers sought to increase solar energy productivity at night by using a technique known as "radiative cooling", a phenomenon that occurs in the evening to lower the temperature by releasing heat into the night sky. The researchers took advantage of this heat, which is supposed to be released by the solar panels at night after absorbing solar energy throughout the hours of the day, and began to collect it to benefit from it in generating electricity at a greater rate than usual at night.

Thermal energy

To obtain this thermal energy, the researchers combined a solar cell with a thermoelectric generation unit (TEG), so that the generating unit is placed below the solar cell, and they are connected to each other by means of an aluminum plate that transfers heat from the solar cell to the thermoelectric generation unit, which is connected on the other side to the surrounding air Through a heat sink, researchers can thus benefit from the heat instead of releasing it into the sky, to be converted later into electrical energy.

Solar innovation experience at night

The innovation experiment for the first time was the first attempt by the researchers to test the prototype of the solar cell integrated with the thermoelectric generation unit in October 2021 on the roofs of a building at Stanford for 3 days, and they concluded that they could produce electric power of up to 100 megawatts / square meter... The authors of the study believe that they can develop the model further, this time they used an ordinary solar cell, and if they could design another for radiative cooling, this would provide a greater temperature difference, which increases the energy that can be produced.

The most prominent design of a solar cell model

Researchers at Stanford University are facing a set of difficult challenges, most notably designing a new model of solar cells that can handle the radiative cooling process, which ultimately enhances electrical energy production. On the other hand, the team plans to expand the scope of the first model, so that the area of ​​the solar cells increases. However, the researchers believe that the cost may be somewhat prohibitive, given the high prices of thermoelectric generation units. However, they are optimistic about the future of this innovation.