Solar energy is an unused source of energy that can be used to produce electricity. Photovoltaic systems contain many different components. Depending on the type, we distinguish between three main types of photovoltaic systems: autonomous, grid and hybrid. Understanding the operation of individual components of photovoltaic systems such as: solar cell, photovoltaic module and converter is essential for the successful design of a solar power plant. In the electrotechnical sense, the project documentation can be divided into: project assignment, conceptual solution, conceptual project, investment study, main project, executive project and documentation for operation and maintenance. When designing a solar power plant, it is necessary to carry out a series of technical calculations such as: estimation of electricity production, calculation of conditions on the DC and AC distribution, calculation of DC cables on the input side of the converter, calculation of losses on the AC side of the power plant and calculation of short-circuit current on the output side of the power plant. Before putting the solar power plant into operation, it is necessary to carry out various tests in order to determine that the power plant is safe for operation with the grid. For this reason, studies of the impact of the power plant on the network and protection settings are being prepared, and an operational plan and program of testing in experimental work are being prescribed.