Wind power gets a striking development in recent years. However, advanced materials and technology for manufacturing wind turbines are necessary but usually unavailable in a developing country like Taiwan. In such a case, the energy inputs during overseas manufacture and transportation of wind turbines are usually ignored as the energy efficiency of a wind power system is surveyed. In this study, three demonstration wind systems -Mailiao, Jhongtun, and Chunfong were analyzed to examine life cycle Energy Return on Investment (EROI) and CO₂ emission for wind energy in Taiwan. The life cycle EROIs were calculated as 13.74, 22.24, and 19.70, respectively, for the three abovementioned demonstration system. The results suggest that the life cycle EROI may violate the rule of the effect of economies of scale if the frequent breakdowns and lacking of wind turbine parts for the equipment repairs are considered. Meanwhile, the EROIs without consideration of energy inputs during overseas manufacture and transportation were 25.09, 40.36 and 36.59, respectively. In other words, the EROIs are significantly affected by the overseas energy inputs. In addition, 47.57% of CO₂ emission of the wind power system occurred in foreign lands, which leads to the underestimation of CO₂ emission in Taiwan. Moreover, the low capacity factors caused by the ineffective wind turbines performance tend to obviously downgrade the EROIs.

View full abstract

International Bureau of Weights and Measures (BIPM) - Consultative Committee for Amount of Substance (CCQM) has conducted international comparisons on quantitative analysis of natural gas components. We participated in one of the international key comparisons for natural gas analysis, CCQM-K23b, as National Metrology Institute of Japan. A pilot laboratory of this comparison distributed the sample gas cylinders to 16 participants (including the pilot laboratory). Nominal composition of sample gases in this comparison was 70 mmol/mol of nitrogen, 30 mmol/mol of carbon dioxide, 94 mmol/mol of ethane, 34 mmol/mol of propane, 10 mmol/mol of isobutane, 8 mmol/mol of butane. The other component gas was methane. In order to measure the sample gas, we prepared our own primary reference gas mixtures by gravimetric blending method. After that, we measured each component in the sample gas with micro gas chromatograph. The accuracy of analyzed concentrations by us were 0.079 to 0.27% as relative expanded uncertainties (coverage factor, k=2). These uncertainties were enough small to participate in this comparison, because the uncertainties were close to those of key comparison reference values for the sample gas. Furthermore, our analytical results had consistency with the results of other national metrology institutes.

View full abstract