Physics / mechanism
Ocean wave energy converts surface orbital motion (gravity-driven capillary/gravity waves) into electricity via oscillating water columns (OWC), point absorbers, attenuators, or overtopping devices. Tidal energy exploits predictable tidal flows through horizontal-axis turbines (analogous to wind turbines submerged in ~2–5 m/s currents) or tidal barrages. Key parameters: wave resource density ~20–70 kW/m of wavefront (Atlantic coast); tidal: 3 MW nameplate units (Orbital Marine O2, AtlantisTec AR2000) achieving ~40–45% capacity factor in strong sites. Global technically extractable resource ~2 TW (wave) and ~800 GW (tidal stream). Both remain pre-commercial at scale; LCOE sits ~£150–300/MWh versus offshore wind £50–80/MWh.
Competitive landscape
Wave and tidal compete primarily with offshore wind for marine spatial allocation and grid connection budget. Tidal’s dispatchability (fully predictable 18.6-year lunar cycle) is a genuine differentiator unavailable to wind or solar.
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.