Shipboard Photovoltaics Integration for Retrofitting Cargo Ships: A Case Study

Retrofitting in the maritime industry is increasingly seen as a strategic approach to enhance performance, sustainability, and regulatory compliance of existing vessels. As the global shipping sector faces growing pressure to reduce its carbon footprint, incorporating renewable energy sources like solar power on board offers a viable means to reduce fuel consumption and greenhouse gas (GHG) emissions. Shipboard photovoltaic (PV) systems provide a sustainable solution by harnessing solar energy to power various onboard systems, typically supplementing auxiliary power, which reduces reliance on conventional fuels and helps meet environmental objectives. Additionally, PV systems are an excellent option for electrical retrofitting, as they can be installed on various ship surfaces, such as decks or superstructures, and operated either off-grid or grid-connected, often without major structural or electrical modifications. This paper highlights key findings from the European-funded “RETROFIT55” project, focusing on the integration of shipboard PV systems into a Kamsarmax bulk carrier, whose structural and operational data were provided by a shipping company partner of the project. In detail, the features of a software tool developed on purpose to optimize the shipboard PV array layout are described; furthermore, maximum installable shipboard PV power, fuel savings and emission reductions from onboard PV generation are assessed quantitatively across various test scenarios.