建立汞流佈之系統動態學模式模擬台灣能源部門空氣污染物之整合減量效益

The Development of System Dynamics Model for Mercury Flow and the Simulation of the Co-benefits of Air Pollutants Reduction on the Energy Sector in Taiwan

施怡瑄(Yi-Hsuan Shih)

指導教授 ： 曾昭衡

國立臺北科技大學/工程學院/環境工程與管理研究所/碩士(2011年)

https://doi.org/10.6841/NTUT.2011.00529

摘要

國內雖有學者研究各環境介質—空氣、淡水、雨水、土壤、底泥及海水等—之汞含量，然而卻缺乏整合健康風險評估以及汞減量政策之成本效益分析。本研究主要目標為建構汞流佈之系統動態學模式，以及台灣經濟海域範圍內國人的汞暴露量。本研究估算台灣成人甲基汞之暴露量帄均為12.72 μg/day，並會增加其髮中汞濃度2.16 ppm。我國2009年碳排放量約為2.8億噸二氧化碳當量(CO2e)。政府減量目標為於2025 年回到2000 年排放量2.3億噸CO2e，為達到此目標，我國能源局計畫於2025年發展燃氣發電及再生能源之發電廠裝置容量達到全國總裝置容量的25%及8%。本研究之BAU情境設定為未來新增之發電量皆為燃煤發電。
經系統動態學軟體STELLA模擬結果，發展燃氣發電及再生能源分冸可避免新生兒未來智商(IQ)降低 0.0388及0.0183分/人(相較BAU)，而分冸減少新生兒未來收入損失及智能障礙者特殊教育支出共1.14及0.54億元/年；另外也可分冸降低溫室氣體0.199及0.167億噸CO2e排放；並分冸避免因指標污染物及甲基汞的暴露而造成的生命年損失價值達994及502億元/年，此部分佔空氣污染造成的社會成本比例高達76.5%。
雖然發展燃氣發電及再生能源能源部門頇分冸較發展燃煤發電額外支出內部成本(設置成本+燃料成本) 644及584億元/年，然而整體社會卻可獲得1,234及675億元/年的社會效益(內部效益+外部效益)。成本效益分析結果，發展燃氣發電及再生能源益本比分冸為1.92及1.15，淨效益(益本差)分冸達591及90億元，故知此二種潔淨能源政策值得政府部門擴大推展。另本研究推估2039年後NG+RE情境國人髮中汞濃度仍將較2009年上升5.5%，超過U.S.EPA的參考劑量(Reference Dose, RfD)1 ppm，顯示汞污染減量是刻不容緩之事。

關鍵字

汞 ； 系統動態學 ； 再生能源 ； 外部成本 ； 成本效益分析

並列摘要

Although there have been studies about mercury levels in environmental media—atmosphere, freshwater, rainwater, soil, and sediment et al.—an integrating model for health risk assessment and a cost-benefit analysis for the mercury reduction policy were still pending. The objective of this study was to develop a system dynamics model for mercury flow and human mercury exposure in Taiwan’s exclusive economic zone. The average methylmercury intake rate of Taiwanese adults was estimated to be 12.72 μg/day, which would cause an increment of 2.16 ppm on adult Taiwanese hair mercury level. The amount of greenhouse gases (GHGs) emission in Taiwan in 2009 was about 280 MT (million ton) CO2e, and the goal of GHGs reduction of Taiwanese authority is to return GHGs emission level to that of 2000 by 2025. To attain this goal, the Bureau of Energy planned to increase the natural gas combined cycle power plant (NG scenario) and renewable energy (RE scenario) to 25% and 8% of the total installed capacity by 2025, respectively. The Business as Usual (BAU) scenario in this study was that all the increased power generating sets are new coal-fired power plants.
From the simulation of the system dynamics software STELLA, under NG scenario and RE scenario, it was estimated that there would be gains of 0.0388 and 0.0183 per newborn in future intelligence quotient (IQ), reductions of NT$ 114 and 54 million/yr in loss of future earning and compensatory education for mental retard, and reductions of 19.9 and16.7 MTCO2e in GHGs emission. Moreover, there would be reduction in loss of life expectancy, which could be transformed by the Value of a Statistical Life (VSL) to NT$ 99.4 and 50.2 billion/yr —as much as 76.5% of the social cost of air pollution— with the reductions of criteria pollutants and mercury emission.
Although the additional internal costs (capital cost + fuel cost) in the energy sector were estimated to be NT$ 64.4 and 58.4 billion/yr under NG and RE scenario, respectively, an increase in social benefits (internal and external cost reductions) of NT$ 123.4 and 67.5 billion/yr under each scenario are expected. The result of cost-benefit analysis shows that the benefit-cost ratios and the net benefit (benefit-cost odds) were estimated to be 1.92 and NT$ 59.1 billion/yr for NG scenario and 1.15 and NT$ 9.0 billion/yr for RE scenario. In summation, both natural gas power plant and renewable energy are worth for the government of Taiwan. Moreover, Taiwanese adults’ hair mercury level in 2039 would still be 5.5% higher than that of 2009 under NG + RE scenario and would exceed the United States Environmental Protection Agency (U.S.EPA) reference dose (RfD) of 1 ppm. It revealed that Taiwan is in urgent need of mercury reduction.

並列關鍵字

Mercury ； System Dynamics ； Renewable Energy ； External Cost ； Cost-benefit Analysis

參考文獻

[99] 許哲豪，應用系統動態模式STELLA模擬臺灣溫室氣體及空氣污染物整合減量效益，碩士論文，國立台北科技大學環境工程與管理研究所，台北，2009。

[100] 陳志寬，應用系統動態模式STELLA模擬台灣交通運輸部門溫室氣體與空氣污染物之整合減量效益，碩士論文，國立台北科技大學環境工程與管理研究所，台北，2010。

[101] 林彥光，評估環保車輛污染減量及補貼機制之效益-應用環境健康整合效益模型，碩士論文，國立臺北科技大學環境工程與管理研究所，台北，2010。

[41] 黃振寬，以空氣資源管理效益整合模型評估溫室氣體與空氣污染物綜合減量之經濟及社會效益，碩士論文，國立臺北科技大學環境工程與管理研究所，台北，2007。

[80] 陳安芃，大台北地區大氣汞濕沉降之時序變化，碩士論文，國立臺灣大學海洋研究所，台北，2006。