This paper presents the technology of photovoltaic concentrator systems, their efficiency and application, and why these systems are increasingly replacing the use of flat photovoltaic systems. The technology of photovoltaic concentrator systems is based on photovoltaic technology that transforms solar energy into electricity through solar panels as a result of the photoelectric effect. It is true that it is more expensive than standard technology, however, it is far more efficient as it uses multi-junction cells that require significantly smaller surface area, and that is the major benefit of such technology. On the other hand, the main disadvantage is the ability to function only under direct solar radiation. The most common classification of the system is by degree of concentration, i.e. how much is the concentrated solar energy flux higher than the flux received on the concentrator. As the degree of concentration increases, so does the need for a more complex cell, as well as cooling systems and mobile sun tracking parts. The paper compares the data of annual electricity consumption on the Island of Vis and data corresponding to the electricity produced by a potential photovoltaic power plant with a concentrator system that uses a multi-junction solar cell. The results show that a 17MW photovoltaic power plant with a concentrator system would meet the annual electricity consumption needs of the Island of Vis. A provisional calculation of the required photovoltaic module is also included.