In the vast, untapped potential of the world’s oceans lies a promising yet underutilized energy source: ocean thermal energy conversion (OTEC). A recent comprehensive review published in the journal “Energy Conversion and Management: X” sheds light on the current state and future prospects of this technology, offering insights that could significantly impact the energy sector.
OTEC harnesses the temperature difference between warm surface seawater and cold deep seawater to generate electricity. With a global theoretical potential of 8-10 terawatts, the technology could theoretically meet a substantial portion of the world’s energy demands. However, practical implementations have faced critical challenges, including low thermodynamic efficiency and high capital costs.
Lead author Fengmei Jing, affiliated with the School of Mechanical Engineering at the Beijing Institute of Technology and the National Key Laboratory of Autonomous Marine Vehicle Technology at Harbin Engineering University, systematically analyzed the evolutionary trajectory of OTEC technologies. The review identifies three emerging research frontiers: thermodynamic cycle optimization, multi-energy integration, and byproduct utilization.
One of the key findings highlights the potential of optimized thermodynamic cycles. “Multi-stage pressure configurations based on organic Rankine cycles and multi-stage heat exchange architectures demonstrate enhanced thermal gradient utilization and improved system exergy efficiency,” Jing explains. These advancements could significantly boost the efficiency of OTEC systems, making them more viable for commercial applications.
The review also explores the benefits of energy hybridization strategies. Integrating solar energy with OTEC systems has been identified as a promising approach to augment operational efficiency. This multi-energy integration not only enhances the overall performance of OTEC systems but also provides a more stable and reliable energy output.
Moreover, the utilization of OTEC byproducts presents a transformative paradigm. “Co-generation applications, such as desalinated seawater, hydrogen storage, and seawater air-conditioning systems, achieve cost reduction in power generation and address critical challenges in sustainable refrigeration and freshwater supply for remote island communities,” Jing notes. These byproducts not only enhance the economic viability of OTEC but also contribute to sustainable development goals.
Despite these advancements, commercial OTEC power plants still face technological, economic, and environmental challenges. The review summarizes these hurdles and offers relevant suggestions to overcome them. By addressing these challenges, the energy sector could unlock the vast potential of OTEC, paving the way for a more sustainable and diversified energy mix.
As the world seeks innovative solutions to meet its energy needs, OTEC stands out as a promising technology with significant commercial impacts. The insights provided by this comprehensive review could shape future developments in the field, driving the energy sector towards a more sustainable and efficient future.