Achieving a blue economy through the circular initiatives: a path towards sustainable marine living resources

This paper empirically examines the role of circularity performance on the performance of marine living resources to prove its role in promoting a sustainable blue economy. We use five different metrics to quantify the marine living resources of nations in the European regions, including the value added at the factor costs of small-scale capture fisheries, shellfish aquaculture, freshwater aquaculture, marine aquaculture, and large-scale capture fisheries. By using various econometric techniques, we provide evidence of the importance of circularity performance in improving the sustainability of the blue economy in the European region during the 2009-2020 period. However, it is more likely that this effect is only positive in the long term. In the long run, circularity performance affects many marine living resource components in a statistically meaningful way.

Economic and environmental impact assessments of a new integrated energy system for ocean applications

Transportation via the world's oceans is a critical way to convey goods and fuels between continents that cannot be performed cost-effectively by any other means. However, the big ships heavily rely on fossil fuels, aggravating global emissions. A great resolution to this dilemma is to employ clean fuels to lower carbon emissions. This research paper introduces a new hybrid compound marine engine involving a gas turbine, a solid oxide fuel cell, and a steam Rankine cycle. Three types of analyses, such as exergy, exergoeconomic, and exergoenvironmental analyses, are conducted on this proposed engine. It is found that the engine combination can produce a power of 15.5 MW, which is more than 48% compared to the marine traditional engine power, and the engine performance has up to 61% energy efficiency and 43% exergy efficiency. However, the exergetic efficiency of this engine based on fuel and product principal is 60%, which is more than 17% compared to its exergy efficiency. This engine has a 218 $/h Levelized cost rate and 139 mPt/h environmental rate. Finally, the average overall specific product exergy cost and environment are obtained to be 59 $/GJ and 20 mPt/MJ. By comparing five fuel blends, methane and hydrogen are the most economical and have the least impact on the environment; the second option is ethanol blend and all fuel blends.

Structural analysis of a fibre-reinforced composite blade for a 1 MW tidal turbine rotor under degradation of seawater

This paper presents a structural performance study of a fibre-reinforced composite blade for a 1 MW tidal turbine rotor blade that was designed for a floating tidal turbine device. The 8-m long blade was manufactured by ÉireComposites Teo and its structural performance was experimentally evaluated under mechanical loading in the Large Structures Research Laboratory at the University of Galway. Composite coupons, applied with an accelerated ageing process, were tested to evaluate the influence of seawater ageing effects on the performance of the materials. The material strength of the composites was found to have a considerable degradation under the seawater ingress. As part of the design stage, a digital twin of the rotor blade was developed, which was a finite-element model based on layered shell elements. The finite-element model was verified to have good accuracy, with a difference of 4% found in the blade tip deflection between the physically measured test results in the laboratory and numerical prediction from the model. By updating the numerical results with the material properties under seawater ageing effects, the structural performance of the tidal turbine blade under the working environment was studied. A negative impact from seawater ingress was found on the blade stiffness, strength and fatigue life. However, the results show that the blade can withstand the maximum design load and guarantee the safe operation of the tidal turbine within its design life under the seawater ingress.

Modeling the impact of innovation in marine energy generation-related technologies on carbon dioxide emissions in South Korea

South Korea has invested extensively in developing revolutionary marine and ocean technologies to accomplish renewable energy goals. Despite that, the available literature offers no insight into the environmental benefits of innovation in marine energy generation, distribution, or transmission-related technologies (IMET). This study examines the nexus between carbon dioxide emissions (CO₂e) and IMET in South Korea (1990Q1-2018Q4). Control variables include international collaboration in green technology development (ICGD), gross domestic product (per capita) (GDPPC), expansionary commercial policy (ECP), and renewable energy use (REC). First, the findings validated the long-run relationship among ICGD, GDPPC, ECP, REC, IMET, and CO₂e. Second, the findings asserted that increasing IMET assisted in the generation of low-carbon renewable energy, thereby contributing to the improvement of environmental quality. Third, the estimates revealed that an increase in GDPPC and ECP was positively associated with an upsurge in CO₂e. Fourth, the data depicted that ICGD facilitated co-green technologies development, which de-escalated CO₂e. Fifth, REC was negatively associated with a decrease in CO₂e. Based on current estimates, this article recommended that governments implement policies that encourage companies and academia to participate in IMET to promote the green economy.

A Bayesian Network model to identify suitable areas for offshore wave energy farms, in the framework of ecosystem approach to marine spatial planning

The production of energy from waves is gaining attention. In its expansion strategy, technical, environmental and socioeconomic aspects should be taken into account to identify suitable areas for development of wave energy projects. In this research we provide a novel approach for suitable site identification for wave energy farms. To achieve this objective, we (i) developed a conceptual framework, considering technical, environmental and conflicts for space aspects that play a role on the development of those projects, and (ii) it was operationalized in a Bayesian Network, by building a spatially explicit model adopting the Spanish and Portuguese Economic Exclusive Zones as case study. The model results indicate that 1723 km² and 17,409 km² are highly suitable or suitable for the development of wave energy projects (i.e. low potential conflicts with other activities and low ecological risk). Suitable areas account for a total of 2.5 TWh∙m^-1 energy resource. These areas are placed between 82 and 111 m water depth, 18-30 km to the nearest port, 21-29 km to the nearest electrical substation onshore, with 143-170 MWh m^-1 mean annual energy resource and having 124-150 of good weather windows per year for construction and maintenance work. The approach proposed supports scientists, managers and industry, reducing uncertainties during the consenting process, by identifying the most relevant technical, environmental and socioeconomic factors when authorising wave energy projects. The model and the suitability maps produced can be used during site identification processes, informing Strategic Environmental Assessment and ecosystem approach to marine spatial planning.