The Determinants of Renewable Energy Project Delays; A Systematic Review

Abstract

The rapid expansion of renewable energy projects has become essential for achieving global sustainability goals, reducing greenhouse gas emissions, and improving energy security. Despite increasing investments in renewable energy infrastructure, many projects continue to experience significant delays during planning, financing, construction, and operational stages. These delays negatively affect project performance, increase implementation costs, reduce investor confidence, and hinder national energy transition objectives. Therefore, understanding the determinants contributing to renewable energy project delays is critical for improving project delivery efficiency and sustainability outcomes. This study systematically reviews the major determinants influencing renewable energy project delays by synthesizing evidence from existing academic literature. A systematic review methodology was adopted to identify, evaluate, and analyze peer-reviewed studies related to renewable energy project implementation challenges and delay factors. Following the application of predefined inclusion and exclusion criteria, 20 studies published between 2020 and 2025 were selected and analyzed. The findings revealed that renewable energy project delays are influenced by interconnected financial, regulatory, technical, managerial, stakeholder-related, and external factors. Financial constraints such as inadequate funding, high capital costs, and investment uncertainty were identified as major delay determinants. Regulatory barriers, including bureaucratic approval procedures and unstable governmental policies, also significantly affected project implementation. In addition, technical limitations, poor project planning, ineffective stakeholder coordination, and inadequate risk management practices contributed substantially to implementation inefficiencies. Social factors such as public opposition and limited community engagement further influenced project continuity, while external disruptions, particularly the COVID-19 pandemic, intensified project vulnerabilities through supply chain interruptions and operational challenges. The study concludes that renewable energy project delays require integrated management approaches involving effective financial planning, stable regulatory frameworks, stakeholder collaboration, and adaptive risk management strategies. The findings provide valuable insights for policymakers, project managers, investors, and researchers seeking to improve renewable energy project implementation and sustainability performance.