Full Life Cycle Assessment Of Buoy-Rope-Drum Wave Energy Converter

With the global warming and the intensification of the energy crisis,wave energy has been valued by many coastal countries and regions as one of the renewable energy sources,therefore,wave energy converters of different technology types have been developed.Although the process of wave power generation does not generate carbon emissions,but the indirect carbon emissions during the entire life cycle of the wave energy converter system should not be ignored.As a widely used environmental assessment method,Life Cycle Assessment(LCA)can qualitatively and quantitatively analyze its energy consumption and carbon emissions and other environmental impacts,This is also an inevitable requirement for wave energy power generation technology to mature This thesis mainly focuses on the LCA research on the buoy-rope-drum wave energy converter developed by Shandong University,and analyzes the environmental impact of its life cycle,in order to provide theoretical support for energy saving and environmental performance improvement for manufacturing of subsequent wave energy converters.The main research contents and conclusions of this paper are as follows:(1)Based on the Life Cycle Inventory(LCI)method,the input and output of the various stages of the life cycle of the buoy-rope-drum wave energy converter are compiled and quantified,and for the first time the marine engineering structural steel in the marine environment Engineering experience such as corrosion loss and offshore maintenance frequency is applied to the LCA research of buoy-rope-drum wave energy converter to achieve a reasonable evaluation of the life cycle structural corrosion loss and maintenance frequency of wave energy converter;(2)The CML-IA baseline and ReCiPe models were used to evaluate the environmental impacts of different stages in the life cycle of the buoy-rope-drum wave energy converter,the results show that the manufacturing stage of the buoy-rope-drum wave energy converter has the most significant impact on the environment,and the environmental impact in the maintenance and use stage is small,especially the floating body module manufacturing process due to the consumption of a large amount of structural steel,which has a greater contribution to the environment;the quantitative results of the CML-IA baseline evaluation show that the photochemical pollution of the buoy-rope-drum wave energy converter has the greatest impact on the environment,accounting for 51.04%of the total environmental load,followed by global warming,accounting for 42.47%;(3)Using the IPCC 2013 GWP evaluation method to study the influence of the global warming potential of the buoy-rope-drum wave energy converter in the temporal scales of 20 years,100 years,and 500 years,the results show that as the number of years increases,the global warming potential value of the buoy-rope-drum wave energy converter shows a gradual decline;(4)The energy consumption and carbon emission intensities of the buoy-rope-drum wave energy converter to be 233kJ/kWh and 38 gCO2/kWh,respectively.The energy consumption and carbon emission paybacks are 15.5 months and 9.4 months,respectively.The comparison of the LCA results of the renewable energy system shows that the wave energy system has obvious advantages and potentials in reducing energy consumption and carbon emissions;(5)Using the ReCiPe assessment method,the sensitivity analysis of the global warming potential of the key input variables shows that the four variables of structural steel recovery rate,electrical steel quality,structural steel quality,and permanent magnet quality are more sensitive High;The Monte Carlo method is used to analyze the uncertainty of four important variables to determine the probability distribution characteristics of the global warming potential of the buoy-rope-drum wave energy converter;(6)Based on the results of the LCA analysis,a variety of solutions to reduce the life cycle energy consumption,carbon emissions and environmental impact of the buoy-rope-drum wave energy converter are proposed,Compare the energy consumption and carbon emssions during the life cycle of the converter under different floating materials,the results show that the use of cast iron,aluminum alloy,and ABS as alternative materials can significantly reduce the energy consumption and carbon emissions of the device.