The main source of energy for most spacecraft is the Sun. But, in order to perfectly accumulate its rays, satellites must have not only photovoltaic converters of a large area, but also special mechanisms for orienting their working surface to the sun. For small probes, the weight of such structures is very large, because scientists from Saudi Arabia offer a common and affordable solution.
At first glance, the idea seems trivial - to make solar panels in the form of a sphere. Therefore, they can be wrapped around a microsatellite or mounted on an external structure, and most of the surface that modifies light into electricity will always be illuminated.
Researchers at the King Abdullah Institute of Science and Technology (KAUST) in Saudi Arabia have already unveiled a model of such a photovoltaic converter in 2020. The technology description was published on the IEEE Spectrum portal.
The new solar panels have a number of advantages that make them suitable for use not only in space, but also on Earth. Due to their almost spherical shape, they collect not only direct starlight, but also reflected light.
In laboratory conditions, spherical photovoltaic converters were 24-39% more efficient than converters in the form of conventional flat plates when simulating the movement of the sun across the sky. And when the light source was obstructed by an obstruction (such as a roof overhang), the new batteries generated 60% more electricity than conventional flat panels.
Technologically, of course, the production of such solar cells is more complicated - firstly, for the manufacture of each photovoltaic converter, and this is a whole field, 15% more etching is required.
In addition, the researchers had not yet fully developed the sphere rolling process, and the test pieces were formed by hand. It is planned to develop a special mechanical arm that simulates the movements of a person rolling on a flexible substrate.
Spherical solar panels are superior to traditional panels in many other ways. For example, they have shown higher efficiency in long-term operation at higher temperatures (perhaps due to more efficient heat dissipation, but this remains to be verified).
And naturally, such structures have an even better situation with surface contamination with dust - which is very important. for huge solar power plants or unmanned vehicles: from sensors in inaccessible places to rovers.
Given all the advantages and disadvantages of the newest technology, scientists are still wary of its commercial prospects. In theory, it can be useful for almost all niche applications - in low Earth orbit for microsatellites, on the surface of other planets for small stationary or self-propelled probes, on Earth for the operation of temporary or permanent sensors, as well as in rooms for IoT devices and smart sensors at home".
Developers of spherical solar cells plan to test them in laboratory and field conditions in the near future according to a number of criteria. They will then assess the economics of the technology.
In terms of the production of light-sensitive parts, the innovation is not revolutionary: photovoltaic cells based on monocrystalline silicon are widely used and perfectly mastered in industry. The innovation of the Saudi researchers lies in the use of a narrow and flexible backing and special processing of the edges of each cell.
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