國際再生能源供應鏈的設計與可行性分析—永續能源方案規劃

Abstract

本研究深入探討國際再生能源供應鏈的設計與可行性，旨在將再生能源從資源豐富的地區運輸到能源匱乏的島嶼地區。研究主要提出三種再生能源運輸途徑：（1）通過鋰離子電池直接運輸可再生電力；（2）通過電解產生的氫氣以壓縮、液化等不同形式運輸；（3）將綠氫轉化為化學能載體，如甲醇（MeOH）、氨（NH3）和甲基環己烷（MCH）進行運輸。各供應鏈從工程、經濟和環境角度進行了全面分析，並通過生命週期評估 (LCA) 衡量環境影響。

在基本案例的假設的分析中，透過化學品能源載體進口的電力成本較在地生產的再生能源高出 8.12 至 13.78 倍。MeOH 和 MCH 在5,000公里以上的長距離運輸中仍顯示出優於氫氣運輸的經濟穩定性，特別是MCH具備較低的製程複雜性和全球暖化潛勢（GWP），適合作為主要長途跨境運輸的能源載體。此外，350 bar壓縮氫氣供應鏈在短於1,000公里的距離上具有競爭力，適合短距離運輸。

另外，本研究提出的供應鏈也適合作為能源儲存系統，有助於解決再生能源的間歇性問題並在緊急情況下增強能源安全。研究結果顯示，鋰離子電池適合日常儲能，壓縮氫氣 (CH2-350 或 CH2-700) 適合頻率長達數週的儲能，而化學載體如 MeOH 和 MCH 則更適合頻率長達數月的儲能，其中由於成本較低且體積較小，MeOH 更適合長期儲能。

能源分析及靈敏度分析的結果顯示，固態氧化物燃料電池 (SOFC) 的效率對於整體能源效率、成本及 GWP 具有最顯著的影響。SOFC的55% 低轉換效率為實踐各國際再生能源供應鏈的瓶頸，顯示其進一步研究和開發以提升整體能源效率的必要性。對於化學載體供應鏈而言，提高氫化製程的效率和降低製程成本是提升整體經濟效益的關鍵，而對於氫氣供應鏈，優化長距離運輸成本則顯得尤為重要。

為支援國家能源規劃與決策，本研究開發一個互動式儀表板，使決策者可調整如運輸距離、再生能源成本和製程效率等參數。此工具提供經濟、環境和土地使用的即時分析，幫助能源匱乏地區根據地理和政策需求優化供應鏈配置。該框架支持向淨零碳排放轉型，並為全球能源永續的未來提供有價值的運輸解決方案。

This study investigates the feasibility and design of international renewable energy supply chains that transport energy from resource-rich regions to energy-deficient regions. Three transport pathways are evaluated: (1) direct electricity transport using lithium-ion batteries, (2) hydrogen transport via compression or liquefaction and (3) transport of hydrogen converted into chemical carriers like methanol (MeOH), ammonia (NH3) and methylcyclohexane (MCH). Each pathway is examined for engineering, economic and environmental viability, incorporating life cycle assessment (LCA) to analyze environmental impacts.

While electricity costs via chemical carriers under base case assumptions are 8.12 to 13.78 times higher than local renewable sources, MeOH and MCH provide superior economic robustness over hydrogen for transport distances beyond 5,000 km. MCH, with lower process complexity and global warming potential (GWP), is ideal for cross-border energy transport. The 350-bar compressed hydrogen supply chain remains competitive for distances below 1,000 km, making it appropriate for short-distance transport.

Furthermore, the proposed supply chains are adaptable for local energy storage, addressing the intermittency of renewables and enhancing energy security during emergencies. Lithium-ion batteries are ideal for daily storage, compressed hydrogen for weekly storage, and chemical carriers like MeOH and MCH for monthly storage, whereas MeOH is more suited for long-term storage, owing to its lower cost and reduced volume.

Additionally, energy flow analysis and sensitivity analysis highlight that SOFC efficiency has the greatest impact on energy efficiency, cost and GWP. SOFC’s current conversion efficiency at 55% represents a bottleneck, signaling a need for further research and development. Additionally, improving hydrogenation efficiency and process costs could enhance chemical-based supply chains, while hydrogen-based chains would benefit from optimized transportation costs over longer distances.

To support decision-making, an interactive dashboard was developed, enabling stakeholders to adjust parameters such as transportation distance, renewable electricity cost and process efficiencies. This tool provides real-time analysis of economic, environmental and land-use impacts, allowing energy-importing regions to select optimal supply chain configurations based on unique geographic and policy needs. This adaptable framework supports the transition toward net-zero carbon emissions and offers valuable insights into alternative transport solutions for a globally sustainable energy future.