Photovoltaic modules are used in transportation equipment such as satellites, airplanes, automobiles, yachts, boats, water streetcars etc. The inventor of the first solar-powered aircraft, shown in Fig. 1 and called Solar Impulse, was Bertrand Piccard. The plane made its first flight in 2010 and completed its round-the-world journey in 2016.

Figure 1: The first Solar Impulse aircraft powered by solar radiation energy. Aut. photo Rama, licensed under CC BY-SA 2.0 FR, source: Wikimedia Commons.

The first unmanned aircraft in Poland was created by the AGH Solar Plane Scientific Association in Krakow ( Fig. 2 ). The aircraft has a wingspan of almost 4 m and weighs only 5 kg and can reach speeds of about 50 \( \frac{km}{h} \). The aircraft is powered by energy from 48 photovoltaic modules with a total output of 167 W.

Figure 2: Solar powered unmanned aircraft made by AGH Solar Plane. Photo: Maciej Talar, KSAF Krakow Student Photographic Agency AGH.

The photovoltaic cells have also found their way into the wings of the International Space Station, which is shown in the Fig. 3.

Figure 3: P4 deployed (International Space Station equipped with P3/P4 solar cells). Photo: NASA, CC0 license, source: Wikimedia Commons.

The automotive market is also a recipient of photovoltaic installations. Electric cars can be charged using electric charging stations as well as electricity generated by photovoltaic cells that are directly installed on the vehicle. An example of the use of photovoltaic cells to power vehicles is the Lightyear One electric car, whose hood, roof and trunk are covered with PV cells totaling 5 \( m^{2} \). This car is presented in Fig. 4.

Figure 4: Lightyear One electric car covered with Lightyear ∞ photovoltaic cells. Photo used with permission from Lightyear ∞.

Modules made of 156 mm by 156 mm monocrystalline silicon cells were used in the Volkswagen T5 California car, shown in Fig. 5. Flexible photovoltaic modules from Solbian's Solbian Flex CP series are used in the car.

Figure 5: Solbian Flex CP Series modules used in a Volkswagen T5 California by Solbian Energie Alternative SRL. Photo used with permission from Solbian Energie Alternative SRL.

An example of the application of photovoltaic systems on vessels is the ship "Harta", shown in Fig. 6. The ship was designed and built by Januszkowice Shipyard. The engines used in the ship are of Polish production made by the Institute of Propulsion and Electrical Machines Komel, while Soltech Service is the photovoltaic and battery supplier. Photovoltaic modules used in the ship project have a maximum power of about 8 kW.

Figure 6: The ship "Harta" equipped with a solar installation by SolTech Service. Photo used by permission of SolTech Service.

Solar cells are also used in boats. Case in point: Maya and Aladino's Vindo 32 from the YouTube channel Sailing Magic Carpet, who have set their sights on circumnavigating the world. The boat, Vindo 32, was equipped with Solbian's SP-Series 130W flexible photovoltaic module made of monocrystalline silicon cells. Solbian's SP-Series flexible photovoltaic panels were also used on the Alibi 54 catamaran, shown in Fig. 7.

Figure 7: Alibi 54 catamaran equipped with 12 Solbian SP series flexible modules from Solbian Energie Alternative SRL. Photo used with permission from Solbian Energie Alternative SRL.

Students from the AGH University of Science and Technology in Krakow have decided to build a zero-emission racing boat powered by \( 100\% \) renewable solar energy. The AGH Solar Boat Team is powered by 384 SunPower c60 series monocrystalline photovoltaic cells, providing up to 1 kW of power ( Fig. 8 ). This energy is accumulated in 1.5 kWh lithium-ion batteries. The team participates in many international solar boat races and in 2018 took 3rd place in the Monaco Solar & Energy Boat Challenge [1].

Figure 8: AGH Solar Boat Team boat powered by solar radiation energy. Photo used by permission of AGH Solar Boat Team.

Photovoltaic cells are also used in tents and sunshades, for example, at the U.S. Army military base in Africa shown in Fig. 9.

Figure 9: Sunshade equipped with photovoltaic cells. Photo US Army Africa, licensed under CC BY 2.0, source: Wikimedia Commons.

Another interesting application of photovoltaic cells is their installation in smart clothing equipped with sensors monitoring vital signs. Researchers from the University of Salento in Italy have worked on this type of solution, developing clothing powered by PV cells with a power of 265 mW [2].
One of the problems of using photovoltaic cells on clothing is the lack of water resistance. A water-resistant garment with a photovoltaic system was made by researchers in Tokyo. They created an ultra-thin photovoltaic cell covered on both sides with a stretchable and waterproof layer. When subjected to stretching and water exposure, this type of cell does not lose its photovoltaic properties [3].