Offshore floating photovoltaic system energy returns assessment—A life cycle energy analysis-based perspective

Abstract

Researchers have long regarded photovoltaics (PV) as a poor energy return (ER) compared to fossil fuels. Although the latter's energy-return-on-investment (EROI), like oil, coal, and gas, are above 25:1 at the primary, they are about 6:1 at the final stage. Following the technology creation, it is essential to investigate whether the solar module technology innovation affects the ER. Much literature delivers the ERs of fossil fuels and PV. However, it does not address the life cycle analysis or life cycle energy analysis (LCEA) assessments. This paper, employing time-series and LCEA analyses, performs an ER evaluation of the 181-MWp global most extensive offshore floating PV (OFPV) in a 30-year life cycle at Changhua Coastal Industrial Park, Taiwan. The results show that the energy payback time (EPBT) is about one year. The EROI is about 29.8, which is superior or complies with the upper limits of previous studies under the same insolation. The approach proposed in this study should help future PV stations' ER analysis and clarify whether the innovation benefits from improving the system's performance. The results also assist in investors' decision-making regarding deploying PV projects in the future.

Keywords

• energy return
• energy return on investment
• life cycle analysis
• life cycle energy analysis
• offshore floating photovoltaics
• energy payback time