Most renewable energy stories focus on wind and solar, but the oceans are an immense, underused source of power. Ocean Thermal Energy Conversion (OTEC) is a technology that captures the natural temperature difference between warm surface water and cold deep water to generate electricity. It’s a renewable supply that is predictable and constant — unlike wind and sun.
The challenge? Designing OTEC systems that are efficient, economical, and practical enough to compete with other clean energy sources. That’s where the latest research steps in.
A Dual-Pressure Twist
The study introduces a dual-pressure OTEC system that combines solar heating with ocean thermal differences. By using two pressure levels instead of one, the system can extract more energy from the same heat flow. Adding solar power boosts the overall efficiency, creating a hybrid that’s stronger than either source alone.
Optimisation with a Purpose
What makes the research stand out is not just the design but the method. The team applied constructal thermodynamics — a way of designing systems to allow flows (like heat and fluids) to move more freely — alongside advanced algorithms (NGSA-II) to test thousands of configurations.
They didn’t optimise for just one thing, like efficiency. Instead, they balanced multiple objectives:
- Maximising power output
- Minimising cost
- Reducing environmental impact
Using three decision-making approaches, they identified system designs that offer the best trade-offs, depending on whether the priority is economy, sustainability, or sheer energy.
The Findings
- The dual-pressure system outperforms single-pressure designs, delivering higher efficiency and greater sustainability.
- When solar heating is integrated, the hybrid system can significantly boost energy production.
- Optimisation shows clear pathways to balance cost with performance, making OTEC more realistic for future deployment.
Why It Matters
For island nations, coastal communities, and regions with limited land for solar or wind, OTEC could provide round-the-clock clean energy. With better designs, the technology can move from niche experiments to a viable player in the renewable mix.
The Takeaway
This research is about more than squeezing a few extra percentage points of efficiency. It demonstrates that by carefully optimising design at every level, OTEC systems can become practical, economical, and sustainable. The oceans have always been a vast, untapped resource — and with smarter engineering, we can realise the full potential of OTEC to support our clean energy transition.
Source
Constructal thermodynamic multi-objective-optimization for a dual-pressure solar ocean thermal-energy-conversion system with NGSA-II algorithm and three decision-making approaches, Energy Conversion and Management, November 2025
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