Application · Marine

Boat & marine wind turbine

At anchor, a small turbine runs all night and keeps the fridge and the autopilot battery alive without starting the engine. The marine version is the same alternator with better seals and a shorter blade span.

A 400 W marine turbine on a 7 m yacht produces 1–1.5 kWh a day in an anchorage with 5 m/s of wind — more than a 200 W solar arch in winter, and it works at 3 a.m. The trade-off is noise transmitted through the hull and the need to reef the blades in a squall.

Everything in the marine version is specified for salt: 316 stainless fasteners, anodised aluminium nacelle, lip seals on both shaft ends, and a blade profile with a thicker trailing edge that tolerates leading-edge erosion.

Typical load profile

Load	Power	Hours/day	Daily energy
Fridge 12 V compressor	45 W	10 h	0.45 kWh
Autopilot	35 W	12 h	0.42 kWh
Navigation & instruments	25 W	24 h	0.6 kWh
LED cabin lighting	20 W	4 h	0.08 kWh
Laptop / phone charging	60 W	3 h	0.18 kWh

Recommended configuration

Recommended model: WT-500M (500 W, 12/24 V)
Mounting: Pole mount on the stern arch, 2.5–3.5 m above deck
Controller: Marine MPPT with alternator dump load
Blade diameter: 1.5 m (shortened for deck safety)
Installed cost: USD 1,400 – 2,300
Daily output: 1.0 – 1.8 kWh at 5 m/s in an anchorage

Noise travels through the hull

Mount the turbine on rubber isolators and keep the pole at the stern, not above the cabin. A turbine that hums at 60 dB in the saloon will be switched off within a week, whatever its output.

Two machines beat one big one

Cruisers who run wind and solar together report far fewer engine hours than either alone. A 400 W turbine plus 300 W of PV covers a typical 2 kWh daily load in most anchorages.

Stop it in a squall

Every marine controller should have a brake switch at the chart table. Furl the blades or brake the alternator before a 40-knot front arrives, not during it.

Frequently asked questions

Will a wind turbine charge my batteries overnight?

Yes, in an anchorage with 4–6 m/s of night breeze a 400–500 W unit delivers 300–600 Wh between dusk and dawn — enough for the fridge, instruments and lights on a typical 35–45 ft yacht.

Can I use a land turbine on a boat?

Mechanically yes, but the fasteners and seals will fail within a season. The marine version costs about 25 % more and uses 316 stainless, anodised housings and dual lip seals.

How much noise does it make on deck?

Around 55 dB(A) at 1 m in a 6 m/s wind. On a pole at the stern with rubber mounts, the saloon level is usually below 45 dB(A) — quieter than a wind generator of the older, geared type.