Floating photovoltaic systems: photovoltaic cable submersion and impacts analysis

TL;DR

This study investigates the durability and environmental impacts of submerged photovoltaic cables in floating solar systems, revealing that saltwater can accelerate cable degradation and copper release, affecting aquatic ecosystems.

Contribution

It provides experimental data on cable degradation in freshwater and seawater, highlighting potential environmental impacts and reliability issues of FPV systems.

Findings

Rubber-sheathed cables degrade faster in saltwater

Submersion leads to copper release into water

Cable insulation loss affects system performance

Abstract

Floating photovoltaics (FPV) is an emerging technology that is gaining attention worldwide. However, little information is still available on its possible impacts in the aquatic ecosystems, as well as on the durability of its components. Therefore, this work intends to provide a contribution to this field, analysing possible obstacles that can compromise the performance of this technology, adding to an increase of its reliability and assessing possible impacts. The problem under study is related to the potential submersion of photovoltaic cables, that can lead to a degradation of its electrical insulation capabilities and, consequently, higher energy production losses and water contamination. In the present study, the submersion of photovoltaic cables (with two different insulation materials) in freshwater and artificial seawater was tested, in order to replicate real life conditions, when FPV systems are located in reservoirs or in the marine environment. Electrical insulation tests were carried out weekly to assess possible cable degradation, the physical-chemical characteristics of the water were also periodically monitored, complemented by analysis to detect traces of copper and microplastics in the water. The results showed that the submersion of photovoltaic cables with rubber sheath in saltwater can lead to a cable accelerated degradation, with reduction of its electrical insulation and, consequently, copper release into the aquatic environment.