Tidal Kite Power — 2D Flight & Power Curve Simulator

Tidal Flow

Current speed 1.2 m/s

Kite

Glide ratio L/D 9.0

Tether length 18 m

Onboard Turbine

Rotor diameter 1.2 m

Live Readouts

Kite speed (through water)

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Flow at rotor

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Power output

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Speed multiplier ×v_c

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vs. fixed seabed turbine, same rotor

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How it works

A tethered kite anchored to the seabed flies a fast figure-eight ("crosswind") loop through the tidal stream. Because the kite is free to move, it doesn't just sample the current speed v_c — it accelerates until drag balances the tether tension, reaching a much higher water-relative speed set by its lift-to-drag ratio:

v_kite ≈ (L/D) · v_c        (crosswind kiting speed, Loyd's law)
v_rel  = v_kite  (flow seen by the onboard rotor, kite-relative)
P = Cp · ½ · ρ_water · A · v_rel³ ,  Cp ≈ 0.4, ρ_water ≈ 1025 kg/m³

Because power depends on the cube of the kite's own speed rather than the current's, a modest current (~1–1.5 m/s — too slow for an economical fixed turbine) can still drive a small onboard rotor at 10–20 m/s of relative flow once L/D is high enough, extracting far more energy per unit of blade area than a turbine bolted to the seabed at the raw current speed. The power curve panel below plots this same cubic curve once and marks both operating points on it, so the gap between them is the whole story. This is the operating principle behind real deep-water tidal kites such as Minesto's "Deep Green".

Current speed — the ambient tidal flow the kite flies through.
Glide ratio L/D — how efficiently the kite's wing converts drag into cross-flow speed; higher L/D means a faster, tighter figure-eight and a steeper power curve.
Tether length — sets the physical radius of the flight path (visual + orbital period), anchored at the seabed pylon.
Rotor diameter — swept area of the small turbine riding on the kite; power scales with area but the cubic speed term still dominates.
Drag inside the flight-plane view to pan, scroll/pinch to zoom — it's a spatial view of the kite's real flight path, not a flat diagram.

Kite + tether Current flow Rotor thrust axis

drag to pan · scroll to zoom

Power vs. relative flow speed (log scale)