Summary
I) What is a hydro generator?
II) Performance
III) The Watt&Sea range
VI) Hydrogenerators at Comptoir Nautique
THE Hydrogen Buyer's Guide
On a boat, the large number of electronic instruments, whether for comfort or safety, require a power supply: the VHF, the autopilot, the radar, the echo sounder, or even the refrigerator and the bilge pump are all connected to a battery. However, this battery has a limited capacity that does not necessarily cover the needs of a ship during a long cruise or a crossing of several days. This is why it is necessary, to compensate for consumption or recharge the batteries, to produce its own electricity in order to be autonomous, without using the thermal engine.
Several solutions are available to us: photovoltaic panels, the wind turbine or the hydro generator. As its name indicates, hydro generator composed of hydro meaning water, and generator: which transforms energy into electrical energy. This last one resumes the principle of the wind turbine, but this time under the surface of water.
In this case, it is the rotation of the propeller under water that powers an alternator. The faster the boat moves, the more efficient the production of electrical resources. This technology, which is still in its infancy, is already one of the most reliable, efficient and virtuous in the maritime environment.
Note that it is quite possible to multiply the electrical sources on a boat. It will be, for example, quite appropriate to use solar panels when anchored, then to prefer the hydro-generator when the boat is sailing.
THE Hydrogen Buyer's Guide
On a boat, the large number of electronic instruments, whether for comfort or safety, require a power supply: the VHF, the autopilot, the radar, the echo sounder, or even the refrigerator and the bilge pump are all connected to a battery. However, this battery has a limited capacity that does not necessarily cover the needs of a ship during a long cruise or a crossing of several days. This is why it is necessary, to compensate for consumption or recharge the batteries, to produce its own electricity in order to be autonomous, without using the thermal engine.
Several solutions are available to us: photovoltaic panels, the wind turbine or the hydro generator. As its name indicates, hydro generator composed of hydro meaning water, and generator: which transforms energy into electrical energy. This last one resumes the principle of the wind turbine, but this time under the surface of water.
In this case, it is the rotation of the propeller under water that powers an alternator. The faster the boat moves, the more efficient the production of electrical resources. This technology, which is still in its infancy, is already one of the most reliable, efficient and virtuous in the maritime environment.
Note that it is quite possible to multiply the electrical sources on a boat. It will be, for example, quite appropriate to use solar panels when anchored, then to prefer the hydro-generator when the boat is sailing.
What is a hydro generator?
History and applications
Developed by an ocean racing legend, the hydro-generator is a relatively recent revolution in the world of sailing. It was with a view to performance and respect for the environment that skipper Yannick Bestaven, winner of the Vendée Globe, devised a sustainable and reliable alternative to the use of fossil fuels, by using the energy developed by the boat's movement in the water. Together with engineer Matthieu Michou, they founded the company Watt&Sea and created a new standard in terms ofelectricity generationat sea.
The principle seems obvious, but putting it into practice has not been so simple. This "sort of hydro-electric turbine " must be efficient without affecting the boat's performance and speed. It was therefore necessary that the hydro-generator, its mast and its propeller, did not generate too much drag which would risk slowing down the sailboat. In the same way, it should not weigh down the boat nor require tedious handling. It is during his regattas and thanks to the feedback from his users that the skipper and his research and development teams have reached a level of performance that allows them to equip most of the ocean racing yachts today: for example, 95% of the boats in the last Vendée Globe were equipped with a Watt&Sea hydrogenerator.
Designed for competition and endurance, this technology is nonetheless accessible to more recreational uses. Recreational sailboats can easily benefit from the advantages of hydraulic power generation, ensuring the necessary autonomy during crossings and cruises. It will be possible to choose the size of the propeller according to your average speed of navigation.
Several types of assemblies are available on the market, each with its own characteristics, allowing the hydro-generator to be adapted to all sailboats: monohull or catamaran
How does a hydro-generator work?
Paddles on a fixed axis, rotating under the effect of the movement of water, thus creating a source of energy... a principle as old as the water mill. But in the case of the hydro-generator, it is not exactly the water that moves in a propeller, but the propeller that moves in the water.
The principle of operation is quite simple, but it was necessary to think about it. Indeed it is the movement of the boat which will create the friction which will drive the propeller of the generator. This implies that the propeller must be constantly immersed in order to offer a stable and efficient performance.
As we can see on this illustration, the propeller is in direct connection with the brushless alternator, itself electrically connected to the 12/24V regulator/converter. This is the one that will supply the batteries with electricity.
On the model shown here (Cruising), the rear panel attachment allows the system to be removable: it can be submerged and raised easily like a rudder.
Once in the water, a cleat keeps the device in position. Once the batteries are charged, it can be raised just as easily.
The Pod 600, works on the same principle, but is not removable. It is installed under the hull, just behind the keel. When it's not possible, due to the boat's architecture for example, to install it on the rear skirt, it represents a perfect alternative.
It offers other advantages: requiring less handling, being more discreet, while producing the same amount of electricity as its rear panel mounting counterpart.
The performance
Efficiency and energy production
I can already hear you: "yes, but I already have solar panels on my sailboat, I can't install a hydro generator on top of that! Well yes, I will answer you. Because the energy sources are not competing, but complementary.
The hydro-generator shows great efficiency, but its electricity production will depend not only on the power of the generator, but also on the size of its propeller, as well as, of course, the speed of movement in the water. In order to best adapt to the consumption of your on-board equipment, it will be necessary to mix the different elements to get the best out of the system: a power adapted to the size of your boat, a length of mast optimizing the immersion of the propeller and a diameter of propeller in agreement with the usual cruising speed of the vessel.
To illustrate this, we have compiled some data from the manufacturer on two flagship models of the Watt&Sea range: the Cruising 300 and the Cruising 600. You will notice the differences in performance depending on the power generated and the size of the propeller (240 or 280 mm).
Technical specifications : Cruising 300 vs Cruising 600
|
Cruising 300 |
Cruising 600 |
|
|---|---|---|
| Size of the boat |
<35 pieds |
>35 Feet |
| Power ratings |
300 W |
600 W |
| Voltage |
12 / 24 V |
12 / 24 V |
| Default propeller |
240 mm |
240 mm |
|
Production at 5 knots with 240mm propeller |
85 W : 7.1 A |
83.5 W : 7.1 A |
|
Production at 5 knots with 280mm propeller |
111 W : 9.3 A |
122 W : 10.2 A |
|
Production at 10 knots with 240mm propeller |
291 W : 24.3 A |
535.8 W : 44.6 A |
|
Production at 10 knots with 280mm propeller |
297.3 W : 24.8 A |
580.6 W : 48.4 A |
To produce more electricity at low speeds, a larger propeller diameter is preferred.
A smaller propeller will produce less energy at low speed, but especially less drag at higher speeds.
To summarize: the faster you sail, the smaller the propeller needs to be to produce more, the smoother you sail, the larger the propeller needs to be. The intermediate propeller design is the most universal, providing good power output on most boats with little drag.
Performance comparison: Cruising 300 vs Cruising 600
Hydrogenerators top sale
When should I choose a hydro-generator?
As we mentioned above, the hydrogenerator, although producing enough electricity to cover the boat's consumption and recharge the batteries, will not be sufficient on its own in the event of repeated or prolonged mooring. It is then that it will be necessary to couple it with a solar or wind system. But are there any contraindications to the installation of a hydrogenerator?
While the installation of a hydrogenerator is fairly simple, it is not always possible to mount it on the transom. In addition, the location must also take into account the roll and heave of the hull, so that the immersion is effective. Indeed, the tilt of the hull can cause the propeller to come out of the water, and not turn anymore.
It is to alleviate these problems, among others, that Watt&Sea proposes a model mounted on a shorter mast, which is permanently fixed under the hull, behind the keel. It will therefore fit all types of sailboats and catamarans, while offering the same performance as similar models mounted on a transom.
THE WATT&SEA RANGE
Cruising 300 and 600 hydrogenerators
The two flagship products of the brand will meet most
of the needs of sailors in the case of cruising or long crossing.
Available with 2 mast lengths and 3 propeller sizes, they are designed for boats under 35 feet (+/- 10m) and over 35 feet respectively.
Developing 300 or 600 watts, they allow to generate enough electricity
to navigate in positive energy and to recharge the batteries if
necessary.
Hydrogenerator Pod 600
The Pod 600 is the hydrogenerator model designed for boats that cannot accommodate the skirt-mounted models.
It provides the same performance as Cruising in terms of electrical production, but offers a space saving, aesthetic gain and an incredible ease of use .
A simple switch is enough to control it.
Hydrogenerator mini 6.50
A very specific model, designed for ocean racing and transatlantic races, the Mini 6.50 is a hydrogenerator for the no less specific Classe Mini.
It provides the reliability and efficiency that skippers need. It is equipped withmanual two-blade propellers with adjustable pitch to respond to speed variations.
Available in 3 mast sizes and 2 types of bindings.
Hydrogenerator racing
The two models of the Racing range, in aluminium or carbon, are optimized for fast sailing, from 5 to 30 knots. Extremely light and particularly hydrodynamic, they generate minimal drag.
They are the preferred models of the world's greatest skippers.
Hydrogenerators at Comptoir Nautique
the marine electronics specialist
The marine electronics specialist is not content to simply offer you the best products for sale at the best prices, he will accompany you with his expertise and his vast experience.
We have chosen for you Watt&Sea hydro generators for their immense reliability, their performance and their innovation.
Our advisors are at your disposal for all your technical questions, your questions about the compatibility of the equipment, or about the available stock, or the delivery time.
Do not hesitate to contact us by e-mail or by phone.