Life Cycle Assessment of an Oscillating Water Column-Type Wave Energy Converter

Among different kinds of renewable energy sources, ocean wave energy offers a promising source of low-carbon electricity. However, despite this potential, ocean wave energy systems can have notable environmental impacts, which remain underexplored. Environmental life cycle assessment (LCA) is a method that can be used to evaluate the environmental impact of these systems. But few LCAs have been conducted for wave energy converters (WECs), and no prior studies specifically address onshore oscillating water column (OWC) devices, leaving a clear gap in this field. This research provides a cradle-to-gate LCA for an OWC device, using the 500 kW LIMPET OWC plant, located on the Isle of Islay in Scotland, as a case study. The assessment investigated the environmental impacts of the plant across 19 impact categories. OpenLCA 2.0 software was used for the analysis, with background data sourced from the Ecoinvent database version 3.8. The ReCiPe 2016 Midpoint (H) and Cumulative Energy Demand (CED) methods were used for the impact assessment. The results revealed a Global Warming Potential (GWP) of 56 kg CO2 eq/kWh and a carbon payback period of 0.14 years. The energy payback period is significantly higher at 196 years, largely due to the plant’s inefficient energy capture and recurring operational failures reported. These findings highlight that although ocean wave energy is a renewable energy source, WEC’s efficiency and reliability are key factors for sustainable electricity generation. Furthermore, the findings conclude the need for selecting eco-friendly construction materials in OWC construction, namely chamber construction, and the advancement of energy-harnessing mechanisms, such as in Power Take-off (PTO) systems, to improve energy efficiency and reliability. Moreover, the importance of material recycling at the end-of-life stage, which was not accounted for in this cradle-to-gate analysis yet, is underscored for offsetting a portion of the associated environmental impacts. This research contributes novel insights into sustainable construction practices for OWC devices, offering valuable guidance for future wave energy converter designs.