Solar power is one of the largest alternative energy and renewable energy sources (RES) segments. Today, it is customary to distinguish between three main solar energy technologies: solar energy can be used to generate electricity (photovoltaics, PV), to obtain concentrated thermal energy for subsequent power generation (concentrated solar power, CSP), or direct heating of the coolant, most often water (solar thermal).
The use of SE in photovoltaics is by far the most widespread. In photovoltaics, the energy of solar radiation is converted into electricity in solar cells, the basis of which are solar cells, or photovoltaic converters (PV). It is customary to distinguish between several generations of PECs, among which the main market share is occupied by the first generation of PECs based on crystalline silicon produced from mono silicon. The most promising and the cheapest are PECs of the third generation based on organic materials. The technical potential of photovoltaics development is connected with an increase in efficiency, i.e. with the efficiency of conversion of sunlight into electric power in PECs.
In concentrated solar power systems (CSP), the energy of the sun’s rays is focused on a concentrated beam of sunlight using a system of lenses and mirrors. This solar beam is used as a source of thermal energy to heat the working fluid, which is consumed for power generation similar to conventional CHP or stored for energy storage. An alternative technology is to produce only hot water in CSP systems.
The simplest example of using solar energy is heating domestic water in special solar collectors. This method is widely used in southern countries such as Israel, Turkey, Greece, China, and Croatia, where solar energy is very profitable.
SE and its use represent current areas for research and technological development. Like any RES, thermal solar power has its characteristics. The main indicator for the efficiency of solar power use is the insolation index of the project region. Insolation shows the intensity of surface irradiation by sunlight and is measured in kWh/sq. m for a certain time interval (day, month, year). The greater the insolation of a region, the more energy from the sun can be converted into electrical or thermal energy. Nevertheless, solar energy can develop in regions with low insolation from the sun, for example, in Germany, which is the world leader in the amount of installed photovoltaic stations, insolation is almost two times lower than in North African countries.
Solar energy, like other alternative energy sources, can be applied and used in various fields of human activity:
- in the form of industrial heat and power plants;
- Solar power plants in the form of installations for supplying commercial, industrial, -administrative, social and other buildings and premises with heat and electricity;
- for installations for private households;
- The use of flexible solar cells as building materials (BIPV) and in the textile industry (SFIT);
- backup power sources in mass consumption products such as calculators, laptops, batteries, etc;
- as a backup power supply for motor vehicles;
- used to illuminate displays, road signs, etc., at night;
- for cooking food.
