臺灣雖已建立完善的再生能源政策架構，工業部門在推動屋頂型太陽能時卻仍面臨實質落差。本研究著眼於制度設計與執行節奏未能對齊的問題，檢視行政流程、設置核准與電網併聯等環節如何交錯影響實務執行。研究以 SWOT 與 PEST 為核心架構，輔以財務與政策工具進行整合式分析，並選擇台積電與台灣康寧–友達兩個具代表性的專案作為觀察起點。透過德國、日本與南韓的制度經驗進行對照，本研究指出，影響推動的不在於政策本身，而是跨部門協調與制度運作效率仍有待改善。此外，大型屋頂型太陽光電具有較佳的投資報酬率與成本分攤效益，讓大型企業更能克服行政與財務門檻，而中小企業則面臨參與困難的結構性限制。唯有透過更具回應性的協作架構，整合基礎設施、法規審查與資金融通，才能讓中小企業與大型企業同樣具備參與能源轉型的可行性。

This study explores the practical and institutional barriers that may limit the growth of rooftop solar adoption in Taiwan's industrial sector. While policy frameworks are mature and technical readiness is evident, the pace of deployment remains constrained by fragmented administrative procedures, uncertain grid integration, and uneven access to financing, particularly for small and mid-sized firms. Larger rooftop solar systems tend to generate more favorable financial returns, making them more accessible to large firms, while SMEs face higher costs and limited capacity to navigate procedural and financial complexity. Using a multi-dimensional methodology centered on SWOT and PEST analysis, and supported by financial and regulatory evaluation, the study draws on comparative insights from Germany, Japan, and South Korea to point out Taiwan's challenges in adopting solar energy technologies. Two cases are analyzed: (1) TSMC and (2) Corning-AUO. Both serve as analytical entry points to understand how firms navigate permitting, investment planning, and execution under current institutional conditions. My analyses suggest that policy incentives alone are insufficient to scale adoption; instead, system-wide alignment across infrastructure, regulation, and institutional routines is required. Only through coordinated and responsive system design can rooftop solar move from ambition to practical realization in Taiwan's industrial landscape.