Clean energy demand in industry 4.0: Trends, challenges, and opportunities

The combination of Industry 4.0 technologies with clean energy systems presents a strategy that offers a pathway towards high efficiency, resilient, and sustainable industrial operations. This review examined progress in six key enablers, namely the Internet of Things (IoT), Artificial Intelligence (AI), Cyber-Physical Systems (CPS), digital twins, blockchain, and additive manufacturing, focusing on energy optimization, renewable energy integration, and transparent, secure, and adaptive energy management. By carrying out a systematic literature review of peer-reviewed articles and conferences in primary databases, we identified trends, sectoral applications, and barriers to implementation. This analysis provides a foundation for advocacy of the Digital-Clean Synergy Framework (DCSF), a four-layer interoperable architecture comprising sensing, analytics, control, and governance to fully integrate digital and clean energy systems. The reviewed literature suggests that combining multiple enablers can reduce industrial energy consumption, increase renewable energy penetration by 8 - 52 % [1], decrease downtime, and enhance carbon accounting and traceability through blockchain. However, DCSF is only theoretical; it lacks large-scale empirical validation, agreed interoperability standards, appropriate cybersecurity practices, or hybrid workforce skills. Further research should include cross-sector pilot deployments, lifecycle assessment, and integration across diverse regulatory and infrastructure contexts to demonstrate scalability and economic viability. DCSF offers a pathway to bridge the policy-technology divide and could serve as a scalable model to accelerate industrial decarbonization in line with SDG 7, SDG 9, and SDG 13.