A recent research shows that removing gearboxes and fine-tuning control settings in tidal turbines can cut harmful acoustic emissions, protecting marine life while keeping tidal power efficient.
When we think of renewable energy, tidal power 🌊 often feels like a quiet hero. It’s predictable, clean, and harnesses the endless energy of ocean currents. But here’s the twist: tidal current converters (TCCs)—the underwater turbines generating this power—aren’t as silent as we might hope.
Like wind turbines humming on land, these devices generate acoustic emissions (underwater noise). For marine life 🐬🐟, this noise can be disruptive, leading to hearing loss, communication issues, and behavioral changes.
The research we’re exploring today, conducted by a team at the University of Edinburgh, dives into how control strategies and design tweaks can reduce tidal turbine noise without sacrificing power output.
Tidal turbines work a lot like underwater wind turbines. They capture the kinetic energy of flowing tides and convert it into electricity. The UK, with its fast-moving waters, has some of the world’s best sites for tidal power. Studies suggest tidal and wave energy combined could meet up to 20% of the UK’s electricity demand.
But while this power is clean and reliable, the challenge lies in the underwater sound footprint.
Why do tidal turbines make noise?
At close range (say, 50 meters), the study found that tidal turbines can generate sound pressure levels (SPLs) around 125 dB re µPa. That’s not enough to cause instant hearing loss in marine mammals, but it can lead to temporary or even permanent threshold shifts (TTS/PTS)—essentially underwater hearing damage.
This is concerning because marine mammals rely on sound for communication, hunting, and navigation. Even small increases in background noise can alter their behavior and habitat use.
The Edinburgh researchers built a MATLAB/Simulink model of a tidal current conversion system (TCCS). They simulated different control settings to see how each affected noise output.
Three strategies were tested:
Each approach offered insights into how tidal turbines can be tuned—or redesigned—for quieter operation.
Noise reduction: ~10 dB at 50 m.
Gearboxes are major culprits in tonal noise. Removing them and adopting direct-drive systems shifts the main noise source to water turbulence instead.
Result: The harmful noise zone shrinks dramatically, reducing risks to marine mammals.
Takeaway: Direct-drive turbines could be game-changers for tidal power, just as they were for wind power.
Changing the MPPT coefficient (Kopt) slightly reduces noise at higher values.
Trade-off: Only about a 3.5% drop in power output for noticeable acoustic benefits.
Bonus: This can be done dynamically! Operators could adjust Kopt during sensitive periods like whale migrations. 🐋
Takeaway: A flexible, low-cost noise management tool that works in real time.
Modifying the switching frequency of power converters (1–3 kHz) had negligible impact on acoustic emissions.
The real noise comes from mechanical and hydrodynamic sources, not subtle electrical signals. 🔌
Takeaway: Don’t expect magic fixes from electronics—focus efforts elsewhere.
The results matter because even small changes in sound pressure level can greatly affect how far noise travels and how it impacts marine species.
This shows that tidal power doesn’t have to be at odds with ocean ecosystems.
The study lays the groundwork for eco-friendly tidal energy development. But what’s next?
Multi-turbine arrays: Future research must explore cumulative effects of many turbines operating together.
Field validation: Lab simulations need to be matched with real-world hydrophone measurements.
Policy integration: Regulators could require noise-mitigation strategies during marine mammal migration or breeding seasons.
Smarter control systems: AI-driven controllers could dynamically balance power efficiency and environmental impact.
🌊 Imagine tidal farms that not only deliver clean power but also blend harmoniously into the marine soundscape.
This research is a reminder that engineering isn’t just about efficiency—it’s also about responsibility. By tuning turbines for both maximum power and minimum noise, we can build tidal power systems that coexist peacefully with marine life.
As the oceans become a key frontier for renewable energy, striking this balance will define the future of sustainable power.
🌊🔋💡 Tidal energy can be powerful, predictable, and—thanks to smart engineering—gentle on the ears of the ocean’s inhabitants.
Tidal Power 🌊 Electricity generated from the natural rise and fall or flow of ocean tides. Think of it as underwater wind power, but more predictable.
Tidal Current Converter (TCC) ⚙️ A turbine-like device placed in fast-moving tidal streams to capture energy and turn it into electricity.
Marine Energy Converter (MEC) 🌍 A broader term for machines that harvest energy from the sea—includes tidal current converters and wave energy converters.
Acoustic Emissions 🔊 The underwater sounds (noise) produced by turbines or machinery, measured to see how they affect marine life.
Sound Pressure Level (SPL) 📏 A measure of how loud a sound is underwater, expressed in decibels (dB re 1 µPa). Higher SPL = louder noise.
Temporary Threshold Shift (TTS) 👂 Short-term hearing loss in marine animals caused by loud underwater noise—hearing usually recovers after some rest.
Permanent Threshold Shift (PTS) 🚫👂 Long-term or permanent hearing damage in marine life from prolonged or intense noise exposure.
Maximum Power Point Tracking (MPPT) ⚡ A smart control method used to squeeze the most energy out of tidal turbines under changing water speeds. - More about this concept in the article "Smarter Grids with Brains 💡🤖 How AI Is Supercharging Renewable Energy Microgrids".
Gearbox ⚙️ A mechanical component that connects the turbine’s slow-spinning blades to a faster generator shaft—great for power, but also a noisy culprit. - More about this concept in the article "⚙️ Powering the Future: Dynamic Response of Next-Gen Wind Turbines 🌬️".
Direct-Drive Generator 🔄 A turbine design that skips the gearbox and connects blades directly to the generator—quieter but heavier and more complex.
Inflow Turbulence 🌪️ The swirling, chaotic water flow that hits the turbine blades, producing both energy and underwater noise.
Source: Jiaqin He, Max Malyi, Jonathan Shek. Analysis and Control of Acoustic Emissions from Marine Energy Converters. https://doi.org/10.48550/arXiv.2509.08656
From: The University of Edinburgh.
