Citation: Mateja, K.; Skarka, W.;
Drygała, A. Efficiency Decreases in a
Laminated Solar Cell Developed for a
UAV. Materials 2022, 15, 8774.
https://doi.org/10.3390/
ma15248774
Academic Editors: Andrzej
Łukaszewicz, Wojciech Giernacki,
Zbigniew Kulesza, Jaroslaw Pytka
and Andriy Holovatyy
Received: 29 September 2022
Accepted: 6 December 2022
Published: 8 December 2022
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Article
Efficiency Decreases in a Laminated Solar Cell Developed for a UAV
Krzysztof Mateja
1,2,
* , Wojciech Skarka
1,2
and Aleksandra Drygała
3
1
Department of Fundamentals of Machinery Design, Silesian University of Technology,
Stanisława Konarskiego 18A, 44-100 Gliwice, Poland
2
SkyTech eLab LLC, Stanisława Konarskiego 18C, 44-100 Gliwice, Poland
3
Department of Engineering Materials and Biomaterials, Silesian University of Technology,
Stanisława Konarskiego 18A, 44-100 Gliwice, Poland
* Correspondence: krzysztof.mateja@polsl.pl
Abstract:
Achieving energy autonomy in a UAV (unmanned aerial vehicle) is an important direc-
tion for aerospace research. Long endurance flights allow for continuous observations, taking of
measurements and control of selected parameters. To provide continuous flight, a UAV must be
able to harvest energy externally. The most popular method to achieve this is the use of solar cells
on the wings and structure of the UAV. Flexible solar cells mounted on the surface of the wings
can be damaged and contaminated. To prevent these negative changes, it is necessary to apply a
protective coating to the solar cells. One of the more promising methods is lamination. To properly
carry out this process, some parameters have to be appropriately adjusted. The appropriate selection
of temperature and feed speed in the laminator allows a PV (photovoltaic) panel to be coated with
film, minimizing any defects in the structure. Covering PV panels with film reduces the performance
of the solar cells. By measuring the current–voltage characteristics, data were obtained showing the
change in the performance of solar cells before and after lamination. In the case of testing flexible PV
panels, the efficiency decreased from 24.29 to 23.33%. This informed the selection of the appropriate
number of solar cells for the UAV, considering the losses caused by the lamination process.
Keywords:
renewable energy; flexible solar cell; lamination; energy harvesting; UAV power
supply system
1. Introduction
External energy harvesting allows for standalone power supply systems to extend
their working time and even achieve full energy autonomy [
1
–
3
]. PV (photovoltaic) panels
allow electricity to be obtained from solar energy, and surplus energy can be stored in
batteries [
4
,
5
]. The use of such systems is gaining more and more popularity in the
electromobility industry in use, among others, in charging stations for electric cars, and
in aviation as an element of the wings or other parts of the vehicle structure. In the case
of UAVs (unmanned aerial vehicles), the operation of a solar cell under the conditions in
which it will be operated should be verified [
2
]. Currently, UAVs are used for, amongst
other functions, distributing shipments, mapping, surveillance, and monitoring of borders
and crops [
6
,
7
]. The biggest research area associated with UAVs is increasing flight duration
without unnecessary landing. For this purpose, systems should be developed to increase
flight duration, optimize the system in terms of weight and provide functionality in all
weather conditions. Obtaining external energy allows for energy autonomy; however, it
is closely related to the location and time of flight [
8
]. The use of solar cells allows for an
increase in flight duration, but it also has numerous limitations that have to be taken into
account during the design of power supply systems [9–11].
The sun is the largest source of free energy on Earth. Solar energy is a renewable,
pollution-free, sustainable, and inexhaustible resource. A solar cell is a device that converts
solar energy into electricity through the photovoltaic effect. The most-used material for
Materials 2022, 15, 8774. https://doi.org/10.3390/ma15248774 https://www.mdpi.com/journal/materials
