What is photovoltaics and what is it used for? Photovoltaics is the process through which we directly generate electricity from sunlight. The most basic form of energy that can be obtained is solar energy. Its utilization is possible through various technologies, primarily photovoltaics.

In simple terms, photovoltaics is used to generate energy. It is the simplest form of electricity generation through the conversion of solar radiation into direct current using photovoltaic panels. The generated current is then sent to an inverter (converter), where it is converted into alternating current, which can power, for example, an entire house. Excess energy produced is sent to the grid and can later be used by the user.

This way of obtaining energy has an advantage over other alternative energy sources such as wind, tidal, or biomass energy. It can be used almost anywhere, and the amount of energy obtained depends on the intensity of sunlight that reaches the Earth's surface, which changes depending on the time of day, season, atmospheric conditions (dust levels), and geographic location.

The power of a photovoltaic installation depends on several factors: the size of the roof or free land, the exposure of the roof surface to the sun, the angle of the roof, and shading. If the conditions are less favorable, for example, there is shading or the roof is oriented east-west, a larger installation capacity should be selected to cover the specified electricity demand.

Investing in photovoltaic panels is profitable. It allows for significant savings on electricity bills, and with the appropriate installation capacity, it can lead to complete reliance on solar energy, eliminating the need for electricity from conventional sources. Additionally, with such savings, the investment can pay off within 7-10 years.

The solar energy market is part of the renewable energy sources (RES) market. It is developing dynamically, and the amount of installed photovoltaic capacity in Poland, Slovakia, and worldwide is growing. This is primarily influenced by the European Union and its requirements for Poland and Slovakia.

Generating energy from renewable sources allows for cost savings. Excess energy that is not consumed can also be sold for profit.

Photovoltaic panel installations primarily enable reducing electricity expenses and even allow for obtaining free electricity with the appropriate number of panels. Due to these savings, the investment can pay off in 9-10 years, with panel efficiency estimated at 35 years.

In Poland, more and more farms are using photovoltaics to reduce electricity costs. Panels can be installed on agricultural buildings and uncultivated land. They can also be installed on the roofs of animal housing buildings (barns, pigsties, poultry houses), with the generated electricity used for internal and external lighting and powering machines and robots in the building. If excess energy is produced, the farmer can sell it and make a profit. This is also an additional security in case of crop or livestock losses, and it can also serve as an alternative to animal husbandry or crop cultivation.

Worldwide, there are solar farms that serve as the main income source for investors who have installed them. This increases the number of people investing in renewable energy installations, including photovoltaic systems, and the government's subsidies or tax benefits further boost investment opportunities.

The functioning of photovoltaic power plants depends on meteorological conditions (sunlight intensity) in the area where they are located.

Sunlight intensity in both Poland and Slovakia ranges from 900-1200 kWh/m2 per year, which supports the development of solar energy. Poland and Slovakia are geographically well-positioned, making them ideal for investing in photovoltaics. In central Poland (around Warsaw, Lublin, Poznań) and in the south (e.g., Kraków, Rzeszów), the highest sunlight intensity can be observed. The highest values of sunlight intensity in Slovakia are in the Bratislava and Žilina regions.

Three generations of photovoltaic cells can be distinguished:

1st generation – monocrystalline (sc-Si), polycrystalline (mc-Si), multi-junction cells (mj-cells), used in space technology;

2nd generation – thin-film cells made of cadmium telluride (Cd-Te), thin-film cells made of semiconductor mixtures (copper, indium, gallium, selenium – CIGS), thin-film cells made of amorphous silicon (a-Si);

3rd generation – dye-sensitized cells, operating on the principle of artificial photosynthesis (Dye Sensitized Solar Cells – DSSC).

Your task is to gather information about photovoltaic installations used in single-family housing. Remember to present statistics on the use of this technology, but also describe the technology itself.

Put yourself in the role of an expert, and your presentation should answer the question of when it is worthwhile to invest in this technology. Present investment and service costs. Provide examples of expected return on investment.

You will work in groups. Each group will prepare a presentation on the same topic. Both the visual and substantive aspects of the presentation will be evaluated. After reviewing the work of the entire class, we will hold a discussion on "Photovoltaics – Polish and Slovak Specialization."

When preparing materials, remember that you must cooperate in the group. Let some of you focus on gathering information, while others will focus on presenting it. You must cooperate; otherwise, you will not be able to prepare the event, and the final presentation will not be useful for you or your classmates.