The development of Floating Solar Photovoltaic (FPV) systems is a sign of a promising future in the Renewable Energy field. Numerous solar modules and inverters are mounted on large-scale floating platforms. It is important to design the system so that the inverter operates in its optimum range most of the time. In order to achieve this goal on the DC side, serial and parallel connections of solar modules are used. As a result, the cabling of the PV array architecture is an important issue. Modern electrical installation design requires reducing costs in cabling materials, equipment installation, and maintenance. The reduction of losses and the amount of time required to complete the design are also significant. Therefore, the main topic of this paper is DC cabling in large-scale FPV power plants (>1 MV). The serial-parallel (SP) connection scheme of solar modules and the percentage of power loss in DC cables are considered. Furthermore, a general method for determining cable lengths for FPV power plants is defined. The temperature influence on losses in DC cables is analyzed. A new method for determining the current at the maximum power point (MPP) as a function of temperature is proposed. A case study is conducted using a hypothetical 3 MW FPV power plant, and the obtained results are presented and analyzed.

The paper analyzes the problem of the construction of utility-scale solar photovoltaic power plants (US-PV). Two main problems of this construction are: occupying usable areas and the connection and integration of the power plant into the electricity system. The construction of US-PV power plants on water accumulations of existing hydro power plants was analyzed, as one of the solutions to these problems. The Jablanica Lake was taken as an example. Jablanica Lake is an artificial accumulation lake on the river Neretva with an area of 13 km2 within the hydroelectric power plant (HPP) Jablanica with 180 MW of installed power. It was shown that on a surface of less than 3% of the total area of the accumulation of HPP Jablanica, there could be built a floating photovoltaic (PV) plant with a power of 30 MW. This power would add another generator of 30 MW to HPP Jablanica, which would increase the current number of the 6 generators to 7. This would enable significantly better exploitation of the Neretva and Rama river basins, and increase production in the summer period with a decrease in lake level oscillations. Suitable locations for the installation of floating solar power plant were analyzed. Locations are selected on the basis of requirements for the preservation of existing lake functions, and provide the possibility of installing a 3 MW power plant. 10 of these plants, connected by a 20 kV power grid, represent one US-PV 30 MW plant, which at one point connects to the transmission network of 220 kV. The specifications of one 3 MW power plant are given in terms of the required area, number of modules and number of inverters. A preliminary techno-economic analysis of the total plant was carried out. In this analysis, the possible production, the indicative price of the plant, and the price of the produced kWh of electricity are calculated.