The DuoGen 3 is a popular combined system of charging with wind and water. It allows you the opportunity to charge efficiently while under sail by lowering the unit into the water, or allow for use as a wind generator while anchored. The DuoGen is specifically designed for the cruiser who is an avid sailor whose main purpose is water generation with the added convenience of wind generation. If your main power generation is through wind, the D400 is your better choice. To change between wind and water generation is fast and simple and without tools. Parts can also be conveniently stowed if need be by dismantling the rotor blades, self-furling protection in high winds as well as the Eclectic Energy’s famous robust construction.

The new DuoGen 3 has a high strength carbon fiber drive shaft, enhanced castings and mouldings and has been designed and refined over thousands of nautical miles under all sea states.

The DuoGen is purpose designed to provide a truly practical solution to battery charging on cruising yachts. DuoGen’s dual mode means that the same machine operates as a wind generator and a water-powered generator.

Water Mode Performance:
8 amps @ 6kts. (100W), 190 Ah per day
11.5 amps @ 7kts. (150W), 275 Ah per day
16 amps @ 8 kts. (200W), 380 Ah per day

Wind Mode Performance:
2.5 amps @ 10kts. wind speed (30W)
6 amps @ 15kts. (75W)
11 amps @ 20kts. (140W)


DuoGen -3 combined water and wind generator

  • On- board electricity generation with DuoGen-3
  • Water mode on passage
  • Wind mode at anchor
  • Mode change in seconds without tools
  • Supplied complete with mount hardware

New for DuoGen – 3

  • Best ever DuoGen
  • High strength carbon fibre drive shaft
  • Enhanced castings and mouldings
  • Design refined over 1000s of sea miles

Water mode performance

  • 8amps at 6 knots (100W) 190 Ah per day
  • 5 amps at 7 knots (150W) 275 Ah per day
  • 16 amps at 8 knots (200W) 380 Ah per day
  • Minimal loss of boat speed
  • Easy to deploy and recover
  • Proven in all sea states
  • Can provide all the power for a yacht on passage

Wind mode performance

  • 5 amps at 10 knots wind speed (30W)
  • 6 amps at 15 knots wind speed (75W)
  • 11 amps at 20 knots wind speed (140W)


  • Available in 12 and 24 volt versions
  • System weight at deck level
  • Low noise, slow revving air blades
  • Air rotor dismantles for stowage
  • Self-furling protection in high winds
  • Robust construction
  • Three tower length versions to suit yachts of all types and sizes
  • High speed water impeller available for faster yachts and multihulls
  • Low maintenance and full range of spares available
  • 12 months warranty


  • To prevent battery damage through overcharging, we recommend a charge regulator is installed with the DuoGen. The recommended regulator is a dump type with an integrated charge splitter, enabling the charging of two independent battery banks at the same time.
Performance & Expectations

The DuoGen was specifically designed to maximise zero carbon electricity generation on cruising yachts. The DuoGen’s unique wind/water capability works best where cruising yachts are making frequent or long sea passages, interspersed with periods at anchor or in harbour.

dragperformance-comparisonThe DuoGen should perform in line with the values given in our published output graphs. However, when monitoring the system, external factors can effect performance, and that may lead you to falsely conclude that there is a problem. To assist in accurate evaluation, particularly in relation to wind mode, be aware of the following:

● When monitoring the wind mode, wind speed measurement should be made at the height of the turbine rotor. Where a mast head anemometer is used, there will be significant wind shear, and it is not unusual for wind speed measurements at turbine level to be 30-50% lower than at the masthead. This is particularly true in harbours and marinas.

● When measuring performance, battery state is also important. Fully charged batteries do not readily accept current, and where a charge regulator is fitted, any dumped power will not be registered by the ship’s battery monitor. In addition, where batteries are fully charged, or the regulator is ‘dumping’, the load seen by the DuoGen’s alternator changes. This makes the alternator ‘stiffer’ to turn, which in turn increases the force which furls the turbine. The increased furling angle reduces the intercept area of the DuoGen’s air rotor which in turn lowers the electrical output.

When evaluating the DuoGen’s air mode, try to ensure batteries are 30 – 40% discharged, or alternatively switch on numerous electrical loads in order to pull the battery voltage down.
● If wind mode outputs remain below expectations, first suspect turbulence in the wind stream. Turbulence at a given site can be specific to a particular wind direction where it is caused by an obstruction either up or downwind of the turbine. When the wind direction changes, and the obstruction is no longer in line with the turbine, outputs may return to expected levels.

● If poor output cannot be attributed to site conditions, re-check the whole installation against the wiring diagram and also look for poor or loose connections. Also, check fuses and fuse holders.

● Finally, ensure that the batteries are in good condition and of sufficient capacity. We recommend a minimum of 300 Ah for use with the DuoGen.

windmode-outputsIf you still suspect a problem with the machine, consider the following:

● Do the air blades spin freely? The air rotor should spin without any undue noise or friction. If not, is there a braking switch engaged or could there be another short circuit in the output cables? (Make sure you disconnect the batteries before trying to find out!)

● Is the DuoGen free to move about its yaw axis? It should move easily with no undue noise or friction.

If in doubt, please contact us.

Note that there is a short period of ‘running in’ with a new wind turbine. The bearings and shaft seals of a new machine take 40 – 50 hours of operation before mechanical friction falls to its design level. As a result, your DuoGen may seem a little slow to respond in light winds until this ‘running in’ period has passed.

*All performance figures are indicative. Actual outputs may vary. E&OE.


The DuoGen is designed to be easily retro-fitted to yachts and multihulls. This represents a substantial challenge because yachts vary widely in size, performance and form.

To accommodate the differences in size, the DuoGen is available in three different tower lengths, short, long and extra- long. The appropriate tower length depends on the yacht’s transom height. This ensures that the angle of the water mode keeps the water impeller immersed, despite heel angle and wave action. It also ensures that when the DuoGen is changed to wind mode, there is sufficient clearance under the air blades for crew safety.


For each tower length we recommend a maximum and minimum mount height above the static water line. We also recommend that where possible, installations are kept within 800 – 900 mm of the yacht’s centre line. This keeps the running depth of the water impeller within the optimum range, regardless of tack.

Note that the majority of DuoGens are installed alongside self-steering systems. The two technologies complement each other, and assuming they are installed 600 – 700 mm apart, will not interfere with each other’s operation.

The table below offers a guide as to which variant is best suited to different yacht sizes. Note that there is considerable overlap and this reflects different hull designs in terms of length over all and freeboard.


Other factors can also affect tower length choice. For example, where a 38 foot yacht is fitted with a stern arch, the extra-long DuoGen may be preferred to the long because it provides greater clearance above the arch for the air rotor. Equally, a 55 foot yacht that only wished to use the DuoGen in water mode could fit the short tower machine, and simply mount it lower on the transom.

The DuoGen is supplied complete with standard mount hardware. This bracketry is designed to accommodate most yacht transoms, and offers a simple and flexible approach to mounting. The bracketry has a range of adjustment and is usually sufficient to achieve an excellent and robust installation. .

Where additional bracketry is required, as is the case with canoe stern yachts and some multihulls, Eclectic Energy can offer advice and bespoke parts.

One of the DuoGen’s key benefits is that most of the system’s weight, i.e. the alternator, is at coaming level. This remains the case in both water and wind mode. Consequently, when operating in wind mode, the mounting only has wind loadings to resolve, not the mass of an alternator.

Installing a conventional wind generator involves a dedicated mount tower and substantial braces fore and aft and athwartships. The cost and weight of this structure is avoided with the DuoGen.

The DuoGen is supplied with full installation instructions. However, it is not always easy to visualise how and where the DuoGen could be mounted, and what clearances will exist when it is operating or being changed from one mode to the other. For this reason we encourage anyone considering a DuoGen installation to contact us and provide a photograph of their yacht’s stern. We then discuss installation options and implications. This is particularly important where a yacht has no push pit rails or has davits or backstays that are secured at the base of the transom.

The mount bracketry incorporates the upper and lower attachment points for the DuoGen. Once the brackets are in place, the DuoGen is installed and secured with a single M10 pivot pin at the alternator, and its tower secured with the upper releasable clamp. This makes it very simple and straightforward to remove the DuoGen for a weekend’s racing.

The electrical output cable is usually taken into the yacht via a cable gland and hard wired within the stern locker / lazarette area. Deck plugs and sockets are not recommended due to the potential shock hazard should they become disconnected.

View the Short Tower SchematicView the Long Tower SchematicView the Extra Long Tower Schematic


Noise and Vibration in Air Mode 

The DuoGen has been carefully designed to minimise noise and vibration. This is particularly important when equipment is operating in close proximity to people.

A certain amount of noise and vibration is unavoidable with any rotating machinery. However if your DuoGen is uncharacteristically noisy, check the points below.

● Identify where the noise is coming from. It can normally be determined whether noise is emanating from the alternator or air drive, i.e. top or bottom of the machine.

● To check the condition of the air drive ‘rotate’ the air blades. They should rotate easily and smoothly with no hard spots. Caution do not attempt this in strong breeze, or allow the air blades to accelerate in the wind.

● Check that the gear cover is not in contact with the hub. If it is, remove the gear cover which is secured by two M4 alan head screws. Straighten the gear cover bracket and refit the cover.

● If roughness or hard spots are felt when rotating the drive, remove the gear cover and examine the gear teeth. Note, a metal gear runs against a nylon gear. Check for wear on the gear teeth and replace worn gears as necessary.  If the gear teeth appear serviceable, clean the gear faces of old grease and dirt, and apply fresh grease. This
should restore quiet operation. If the air drive remains noisy, check the backlash between the gear faces and adjust if necessary.

● If the noise does not emanate from the air drive, check the upper tower bearing. This is the beige coloured, spherical bearing at the top of the main tower through which the stainless steel outer drive shaft sleeve runs. Note, the bearing surface itself is a grey coloured, ‘high speed’ bearing liner. If there is undue play at this top, check that the bearing liner is still in place.

● At the lower end of the outer drive shaft, a rubber-lined stainless steel coupler is used to connect the telescopic drive shaft to the alternator shaft. Later models (DG3) feature a one piece nylon combined reducer and coupler. To access this, remove the main tower. Check the condition of the coupler and ensure the lower M6 securing bolt has not been over tightened. If this bolt is fitted incorrectly, it can pull the drive shaft off centre, causing vibration and uneven running.

● With the main tower and drive shaft removed, try rotating the alternator by hand. It should rotate smoothly and quietly. If it feels ‘heavy’, like turning something in glue, suspect a short circuit and refer to section on electrical faults. If there is any roughness or hard spots, suspect a mechanical fault. This could be due to failed bearings or mechanical contact between internal rotating parts. The alternator must be dismantled to replace the bearings. Alternatively, the alternator can be returned to a dealer or Eclectic Energy for service.

● Poor installation or loose mounting can be a source of noise and vibration. Review the section of this manual on installation, and check all fasteners for tightness. In some cases, particularly in lightly- built yachts with thin, resonant panels, it may help to place a substantial plywood backing pad behind the universal bracket foot. Should the yacht’s pushpit be unduly flexible, an additional stiffening strut can be added to the mounting, running from the universal bracket to the coaming or the deck, just forward of the coaming.

● Ensure that the yoke lock is applied when operating in wind mode.

Excessive furling in wind mode

● The DuoGen is designed such that the yaw arm and air rotor will progressively turn away from the wind as wind speeds increase. This reduces the intercept area of the rotor, from a full disc in lower winds, to an ellipse of reduced area in high winds. Due to the cubic relationship between wind speed and energy, electrical outputs will continue to rise. However, the furling does moderate the wind loadings on the DuoGen, and on the yachts moorings.

● The furling is a result of the balance between the torque reaction resulting from back EMF within the alternator (i.e. how hard it has to work to drive the charging current) and the pressure of wind on the rotor disc and the yaw arm. Anything that makes the alternator ‘stiffer’ to turn will increase the furling force.

● Mechanical friction – undue friction in the air drive, drive shaft or alternator can produce excessive furling, Refer to previous section to evaluate.

● Electrical influences – the DuoGen will furl least when open circuit, or running into a deeply discharged battery bank. As the batteries approach fully charged, the furling angle will increase. When the charge regulator is acting, this connects the dump load,resistors changing the electrical load the alternator is working into. This will also result in an increase in the furling action.

Note, by using the yaw arm’s springer plunger to lock the tower, the furling action can be disabled. This will generally result in increased outputs, but is only viable when the yacht is lying to an anchor or mooring and is free to ‘weathercock’ i.e. keep her bow to the wind.

To read more about “Water Drive Checks” and “Low Power Outputs” please read page 37 of the Duo Gen Manual by clicking here.


Duo gen Manual

Duo gen Regulator Manual

Duo gen Schematic Short Tower (10601)

Duo gen Schematic Long Tower (10599)

Duo gen Schematic Extra Long Tower (10600)

Duo Gen Routine Maintenance

The DuoGen is designed to require minimal maintenance, but a little attention will pay dividends in terms of appearance and performance.

If the yaw action becomes stiff and unresponsive periodic washing with fresh water will remove accumulated salt deposits and keep the yaw bearings and the telescopic drive shaft sliding smoothly. An occasional application of a domestic silicone- based polish on the tower tube and drive shaft is also recommended.

The alternator requires no maintenance as it is hermetically sealed, and the bearings are protected by a twin lip radial shaft seal.

The water mode is robust and efficient, and maintenance free as the impeller transmission device is lubricated by a combination of synthetic oil within the matrix of the bearing material and water.

When dry following immersion in sea water, the unit may feel a little stiff. This is due to dry salt deposits and the unit should free up immediately it is returned to the water.

However, the DuoGen’s water impeller rotates about 5 million times for every thousand miles sailed, and like all mechanical devices, it is prone to wear.

We recommend that the transmission elements are replaced every 8- 10,000 nautical miles, or 40 – 50 million revolutions, in order to maintain optimum performance. This is a straightforward procedure that can be undertaken by the owner.

The DuoGen’s air mode transmission device incorporates a heavy duty gear set and thrust bearings, all running behind grease seals.

The gear faces benefit from the occasional light application of a good quality weather resistant grease, as supplied.