Hydrogeneration - recovering energy from water

Q: Does hydrogeneration affect drag resistance?

Additional drag is minimal compared to energy benefits.

sierpnia 25, 2025

1154 odwiedzin

Hydrogeneration - recovering energy from water

What is hydrogeneration and how does it work?

Hydrogeneration is a breakthrough technology that enables electric propulsion to function as a generator. When the boat is in motion, water flow drives the motor, which produces energy, charging the batteries without any external power supply.

This simple, eco-friendly solution is ideal during sailing or towing, allowing energy recovery and significantly extending autonomy on water. Thanks to the higher density of the water medium, a hydrogenerator can deliver much more current than, for example, a wind turbine of the same size.

How does hydrogeneration work in practice?

The hydrogeneration process is based on the simple principle of reversing electric motor function:

Automatic activation : the function engages above approximately 6 km/h speed.
Energy generation : water flow drives the propeller, which rotates the motor operating as a generator.
Intelligent management : the process stops automatically when the battery reaches approximately 90% capacity.
Power increase with speed : generated power increases with vessel speed, up to reaching the limit depending on the model.
Safe shutdown : the system automatically shuts down at excessively low speeds.

X-Series hydrogeneration characteristics

Power generation chart for X-Series motors depending on speed

Generated power characteristics for X-Series motors as a function of speed

X-Series motors (X12, X20, X40) offer efficient hydrogeneration from low speeds:

In X-Series motors, energy recovery operates from speeds of approximately 3-4 knots. At 8 knots (approx. 15 km/h) it's possible to generate over 600 W of energy , and at 10 knots we achieve ~1200 W (X12 with low-pitch propeller).

This is sufficient power to steadily charge the battery pack during navigation, significantly extending vessel range and autonomy.

Hydrogeneration in I-Series motors

Power generation chart for I-Series motors depending on speed

Generated power characteristics for I-Series motors as a function of speed

I-Series motors (I10, I20, I40) also support hydrogeneration, although initially this function was in testing phase and was not included in earlier manuals.

Test data shows impressive results:

I10 achieves up to approx. 1.4 kW at speeds of ~18-19 km/h
I20 generates up to 2.1 kW at similar speeds

These values place the I-Series among the most efficient hydrogeneration systems available on the market.

Hydrogeneration and Evo Series - technology pioneers

Evo models (Spirit, Navy, Pod Drive) were the first to introduce hydrogeneration in ePropulsion and they were most commonly associated with this function.

In X and I series, the functionality is available but used less frequently - mainly on sailing yachts and recreational vessels, where longer sailing distances without using the motor as propulsion can realistically be expected.

Evo series remain the benchmark for this technology development and are still widely used in applications where hydrogeneration constitutes a key element of the energy system.

Why does hydrogeneration make sense?

Water > wind

Thanks to the higher density of the water medium, a hydrogenerator can deliver much more current than, for example, a wind turbine of the same size.

Efficiency increases with speed

Generated power increases with travel speed - the faster you sail, the more energy you recover.

Automation

The system operates fully automatically, without requiring user intervention - simply sail above minimum speed.

Benefits of hydrogeneration

Automatic charging

No unnecessary navigation interruption - batteries charge during normal operation, without the need to stop.

Environmental friendliness

Clean renewable energy utilizing the vessel's natural motion - zero emissions, maximum efficiency.

Efficiency

Better energy return than wind or solar power with comparable device sizes.

Range extension

Longer voyages without shore charging - autonomy increase of even several dozen percent.

FAQ – frequently asked questions about hydrogeneration

Hydrogeneration activates above approximately 6 km/h (3-4 knots).

No, the system automatically stops the charging process when the battery reaches approximately 90% capacity, protecting it from overcharging.

This depends on speed, sailing time and motor. The larger the motor, the more it produces, e.g., I-20 at 15km/h (8 knots) produces approximately 1000 W, which gives 1 kWh of energy per hour.

Hydrogeneration is available in Evo, X and I series as well as in Pod Drive series.

Hydrogeneration utilizes natural water flow through the propeller during motion, so additional drag is minimal compared to energy benefits.