Floating Solar PV technology is already in widespread use overseas, but there are unusual challenges such as inverter types and installation methods, which can be implemented either by installing on ground (onshore) or on the body of water(offshore).

In Floating Solar PV applications worldwide over the past years, many small-scale Solar PV plants have been realized by offshore and onshore inverter applications, while the large ones (Multi-Digit MW scale) have been realized mostly by offshore inverter applications. There is no single choice that results in an optimal installation method; instead, a wide range of technical and commercial requirements must be weighed in combination with the customer’s needs. In the end, efficiency is what counts.

There are determining arguments when deciding between onshore and offshore inverter installation methods, such as the distance to the shore, transmission systems (AC/DC), size of the plant and inverter technology (String/Central).

In terms of working principle and topology, there are no significant difference between onshore and offshore inverters. The main differences might be mechanical, such as protection classes and corrosion levels of offshore Solar PV inverters.

The potential of a Solar PV inverter is very important parameter to calculate overall system efficiency. A few years ago, the solar benchmark for electrical potential was 600 V_DC. Then 1000 V_DC systems are the most common and now 1500 V_DC is the new level. In the following years the benchmark will reach 2000 V_DC. But the time required for product certification and regulation delays the adoption of the next level. These developments in the electrical potential of Solar PV inverters improve the overall Solar PV power plant system efficiency.

The type of electrical current is another important argument, which can be divided in two as Alternating Current (AC) and Direct Current (DC). Central inverter input is compatible with Direct Current (DC) and nowadays 1000 V_DC and 1500 V_DC system components and applications are practically in use. As it is highlighted above, if the distance between the floating membrane and inverter increases, the system efficiency decreases. Therefore, it is always much more effective to use higher potential system to decrease energy losses over the conductors.

The report has been prepared for assessing offshore and onshore inverter installation methods for current and future applications of a Floating Solar PV project, which is under development phase and being planned to be installed on Hydroelectric Power Plant reservoir water. In the report, different installation methods have been examined from different perspectives and the result is summarized.