wind power for sailboat

Better Sailing

Best Marine Wind Turbine Generators For Boats

Unless you are happy burning endless amounts of fuel, a marine wind turbine is an essential item fr an offshore cruising sailboat. In this article, we will be taking a look at some of the best wind generators for your boat.

Today’s cruisers carry so much electrical equipment that wind turbines, solar PV arrays, and hydro-generators are becoming more and more common. The marine wind turbine has been around for several decades now and has gradually been refined to give a much higher degree of efficiency. Better alternators, CAD-designed blades, life-sealed bearings, and smart charge controllers make the latest devices more reliable, quieter, and safer.

Things To Consider When Shopping For a Marine Wind Generator

Horizontal axis vs. vertical axis wind turbine.

The majority of marine wind turbines are horizontal axis devices, either upwind or downwind driven. These are powerful and, as such, need speed and/or charge output limiters, or they can burn out the batteries and self-destruct in storm-force winds. Vertical axis turbines are more suited to trickle charging – usually connected to one or two batteries up to 200Ah capacity. The blade design means they are unidirectional and thus have no need for a bulky tail fin to point them into the wind. They are also considerably quieter than most horizontal turbines and much easier to mount and install.

Vertical and Horizontal Axis Boat Wind Turbine

What Blade Design Should Your Wind Generator Have?

Modern turbines usually sport a one-piece, cast aluminum body and, commonly, three aerodynamically designed plastic/composite blades. One of the first of these models, the original Air-X, worked exceptionally well, particularly in high winds. However, it was so noisy that neighboring boats frequently complained, leaving the owner the option of turning it off or moving well away from other boats. Since then, CAD-inspired blade design has significantly helped to reduce ambient noise levels, although none could be termed silent.

Once your battery bank is fully charged, additional energy from the turbine needs to be dissipated, or the turbine stopped. Low power vertical-axis models don’t usually produce enough to warrant fitting a regulator, but the more powerful models all need some form of charge limiter to prevent overcharging. The simplest form of regulation is to switch it off when no further charge is needed. If you electrically disconnect the turbine, however, it can either damage the alternator diodes or carry on spinning at an even higher speed, so most are electrically ‘braked’ by shorting out their output wires, and a high-current switch is usually provided for this action.

If you leave a turbine running unattended, you’ll need an automatic regulator, and there are two systems commonly available. The first lets the turbine continue to spin and produce power, diverting any that isn’t needed into ‘dump’ resistors to burn off the excess as heat. While effective, it is pretty rudimentary, and you have to be careful where you mount the bulky resistors, which can get quite hot. Alternatively, some use this unwanted charge to pre-heat the hot water tank via an immersed element. Other turbines incorporate ‘pitch control’, comprising feathering blades that either flatten out or turn edge into the wind to regulate turning speed at high wind speeds.

Charge Controllers

A variety of automatic charge controllers are available, some more sophisticated than others, and you don’t necessarily need to use one from the same manufacturer unless it specifically states that you must. A basic model has a voltage-sensitive on/off switch that will trigger at a pre-set threshold battery voltage. The more useful controllers have a built-in display for monitoring turbine output and battery condition. Some can also accept and distribute charge from other sources, such as solar or hydro generation.

>>Also Read: Best Portable Boat Generators

Here Are Some Of The Best Best Marine Wind Turbine Generators For Sailboats

Auecoor solar wind hybrid system – best marine wind turbine generator on amazon.

The Auecoor Solar Wind Hybrid System is the best system to hook your boat/sailboat with. It is a hybrid system that utilizes both solar and wind power generation. This system is highly efficient, it is designed to withstand heavy wind loads, and it is ready to install on a boat/sailboat. They also produce many models to serve your needs, from 500 Watts all the way up to 2000 Watts in optimal weather conditions.

All models come with a 400-Watt wind turbine generator, and then you can add as many 120-Watt high-conversion, waterproof and flexible solar panels as you need. This unit is also pretty easy to install. The solar panels are easy to transport, and they come with pre-drilled holes for easy installation. This is my personal favorite kind of setup and the one that I believe is the best for any serious boater. It provides 2 renewable sources of power that guarantee that whether you are making a passage or liveaboard in a nice beach somewhere, you will have dependable power as if you were living connected to the grid.

Auecoor Solar Wind Hybrid Generator System - Best Marine Wind Turbine Generator on Amazon

Air Breeze 200

Although the latest generation Air Breeze, made by Primus Windpower, provides an increased charge output, it is also quieter and should apparently outlast its predecessors. Its low start-up speed (4.2kn) means that, on average, it should be able to produce more energy than some higher-rated turbines over long periods of low-to-moderate wind speeds. Though it only has a maximum output of 200W, its output has been optimized to provide a more constant charge in typical northern European and Mediterranean wind conditions. The new Air Breeze weighs less than 6kg and has an integral electronic charge controller and over-speed regulator, rendering bulky dump resistors unnecessary and making installation considerably quicker and easier.

Leading Edge LE-300 or LE-450

A UK company, Leading Edge supplies wind turbines for both marine and terrestrial installation. The LE-300 and LE-450 are available in 12V, 24V, and 48V versions and are remarkably light, making them ideal for sailing yachts. The output is DC via two wires, and a run/stop switch is supplied that breaks the turbine by shorting the output. The units can also be supplied with charge controllers, a dump load style regulator that allows you to leave the turbine on 24/7 without the batteries overcharging. The three-bladed LE-300 is very light (6kg) and one of the quietest of the three-bladed models. However, its output is poor for a horizontal-axis turbine, although it starts spinning in the gentlest breeze. The five-bladed LE-450 is more powerful (105W at 15-knots) while remaining quiet and stable. Another great feature of this wind turbine is that it is the quietest marine wind generator tested.

Rutland 1200

The latest in the Rutland wind turbine line up, the 1200, is Marlec’s answer to the third generation three-blade, permanent magnet turbine models. More powerful than the 914i, it features a ‘Tri-namic’ blade design, which is said to provide a low start-up speed, very quiet running, and more power towards the top end of the wind scale. With a claimed peak production of 483W (that’s 35.5A at 12V) in 29 knots of wind, the 1200 can also supply a very useful 40W of power in just 10 knots of wind – a more realistic average in most waters.

The 1200’s charge controller has dual outputs for two separate battery banks and can accept up to a 20A solar PV supply. It reduces the turbine speed automatically after winds reach 30 knots, regulating the charge without using dump resistors. It also has an integral start/stop switch and can support a remote display, which connects to the controller via a simple Ethernet cable.

Eco-Worthy Wind Solar Power Kit

What can I say? I just love a good wind-solar hybrid power generator. With this kind of setup, you won’t have any problem charging a 12V or 24V battery bank with this hybrid system throughout the day, in any weather condition. The Eco-Worthy Wind Solar Power Hybrid generator can guarantee enough power for you to remain comfortable on your boat and operate any appliance you need and enjoy your time on the boat. You can purchase any model that fits our needs starting from 400 Watts all the way up to 1,400 Watts. However, always buy a generator that has a higher power output than you think you will need because you almost always won’t be in optimal climate conditions.

ECO-WORTHY 500W Wind Solar Power Kit: 400W Wind Turbine Generator+ 100W Monocrystalline Solar Panel for Off Grid 12 Volt Battery Charging

The blades on this German-built device are very steeply pitched towards the hub, resulting in an early start-up in lighter airs, and they also incorporate tiny fins along their length, said to quieten them at high speed. The blades have a kinetic rotor pitch control system designed to feather them in very high winds, not unlike the large terrestrial wind turbines. With a charge controller in the circuit, the turbine can therefore be left spinning in all weathers without worry. The output is two-wire 12V or 24V DC, so it could, in theory, be directly connected to a battery bank.

It can also be used with a simple short-circuit stop switch, which will slow it down enough to be tied off. The Superwind 350 can also be supplied with a 40A SCR Marine charge controller, which has two independent, diode-isolated outputs for start and service battery banks and dissipates unwanted energy via two large, wire-wound dump resistors. Nominal power is 350W at 25 knots.

Silentwind 400 Wind Generator

As fitted to all boats in the Volvo Ocean Race and featuring ‘Silent Power Blades’ – hand-laminated carbon blades, successfully tested at hurricane speeds – the latest Silentwind 400+ has improved wind tracking and earlier start-up than its predecessor, the 400. Featuring aerodynamics combined with a three-phase Neodymium-Iron-Boron permanent magnet generator, the 400+ is said to have a start-up speed of only 4.3 knots and a peak output of 420W at 30 percent less rotation speed than other 400W generators. 12V, 24V, and 48V models are available.

The Silentwind has a 3-wire AC output, which connects directly to the matching hybrid multi-stage charge controller that enables trickle charging and the connection of up to 20A of solar PV power. An adjustable boost function increases performance and optimizes the power yield, while the LCD displays all the important charge information. When the batteries are fully charged, the turbine automatically stops or switches to trickle charge mode with a significant reduction in rotation speed. It can also be stopped (braked) manually with the built-in switch on the controller.

Rutland 504 Wind Marine Generator

The Rutland 504 is a small and lightweight (just 3.5kg) mini-horizontal turbine from the UK off-grid power specialist, Marlec. The earlier model (503) has proven to be extremely popular over the years, in both the small leisure craft market and in commercial applications such as remote street lighting and signage, buoy lights, ATON power, etc., and the 504 should prove equally so. Like its predecessor, it is very compact, and its blades are ‘encapsulated’ – i.e., they have a protective ring around them to prevent limbs and clothing from getting caught up in the blades. Its output is better than that of the vertical-axis turbines but nowhere near the more powerful generators listed above. It is, however, notably quieter.

Typical output is around 15 knots of wind is 12W (1A @ 12V), doubling to 24W/2A at 20 knots. It also has a lower start-up speed than the vertical turbines and, although it takes around 10 knots of wind to provide any useful charge, its low-friction alternator compensates for the gusts by ‘smoothing out’ its output. The 504 does require a charge controller if it is to be left unattended.

Leading Edge Vertical Wind Turbine

The LE-V50 and V150 vertical axis turbines are compact, lightweight, and virtually silent. The V50 measures 270mm dia x 456mm high and is intended for trickle-charging batteries or for running low-power devices. Available in 12V, 24V, or 48V versions, it has a nominal output of 12W but a peak of 70W. In typical waters, this results in an average charge of 0.5-1.0A @ 12Vdc in a fresh breeze. The bigger V150 model has a peak output of 200W but a more typical rating of 24W in wind speeds of 15 knots – double that of the V50.

Leading Edge wind turbines were originally designed to generate power for industrial data monitoring equipment in very remote areas where there is no other power source; these often supplement solar PV arrays in an off-grid sailing situation.

>>Also Read: How to Charge a Sailboat Battery

Final Thoughts

There you have it; these are the best Best Marine Wind Turbine Generators for your boat or sailboat. Whether you are boating/sailing during your holidays or liveaboard full-time, a reliable power source is necessary. It will always provide you with the necessary power to operate your essential electronics, and depending on the power output you go for, it can fill up your batteries without an issue. Remember that when you are out in the water, it will be near impossible that there won’t be enough wind for a marine wind turbine to generate power, so you will rarely be without power. However, that’s why I always sail with both a wind generator and solar panels on board.

Peter is the editor of Better Sailing. He has sailed for countless hours and has maintained his own boats and sailboats for years. After years of trial and error, he decided to start this website to share the knowledge.

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MarineKinetix MK4+ Marine Wind Generator

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Product Description

The marine industry’s highest rated wind generator.

MarineKinetix MK4+Wind Generator, including Controller - For Lead Acid, AGM, Gel and Lithium Batteries.

The marine wind generator with a 100% satisfaction guarantee, and the industry's best 3-year limited warranty.

Double click on the large picture above to scroll through scores of pictures of fellow bluewater cruisers worldwide relying on power from their MarineKinetix wind generator. Also see a blog from a seasoned bluewater cruiser and Salty Dawg Rally organizer who solved his large energy demands using a combination green energy, including an MK4+ wind generator here .

The MarineKinetix Wind Turbine has become one of the most popular marine wind generators available due to its advanced technology, superior output, and super-quiet design. The MarineKinetix is now considered to be the benchmark among serious cruisers. With a 30% to 50% larger swept area than the most popular marine wind generators, it is simply capable of intercepting more of the available windstream, and capturing more power. Its sophisticated microprocessor-controlled charge controller displays all the data, including wind Amps, Watts and Volts, and assures that the power makes it safely and efficiently into your battery bank through a 2-stage smart charging process. No need to buy extra meters , rectifiers, stop switches, or load diverters. These are integrated into our smart controller. Just add your mounting pole and the wiring to your batteries, and you are ready to start producing green energy.

We are celebrating our 12th year of serial production, and our 8th year producing our latest design, the MK4+ Marine Wind Generator. The MK4+ replaced the popular MarineKinetix MK450. Our wind generators are in use from the southern ocean to the arctic ice shelf.

The MK4+ includes the following upgrades:

The Wind Generator body is smaller and even lighter than the original design. This is accomplished with a shorter, but more upright tail, with a greater surface area, and lower polar moment, for faster, and truer wind-tracking. This lowers yaw error and improves performance in shifting winds.
Upgraded asymmetrical pole-shifted rotor with 12 (vs 10) neodymium rare-earth magnets for more power and zero cogging. Bread-loaf magnet design for optimum air gap.
Upgraded 36-slot stator with premium heavy-gauge copper windings.
A new and improved anti-corrosion marine grade finish, which starts with a new high-pressure die-cast magnalium body, which is GEOMET zinc-nanocoat pre-treated, then top-coated with a high-quality corrosion-resistant thermoset marine powder coating. No other marine wind generator uses this anti-corrosion process
New double yaw bearings. Double bearings provide a larger "wheelbase" for the yaw joint, which reduces any free play, which can contribute to vibration and noise.
Improved silicone o-rings which are totally weather-proof.
Improved Aero'coustic 20% carbon-fiber filled injection molded blades, which are 18% more rigid than the previous design.
All new Hybrid Wind/Solar Charge Controller with LCD display - with integrated battery monitor, stop switch, ammeter and watt meter. (no need for expensive monitoring panels).
Patented 2-Stage PWM Charge Controller - Increases the efficiency of the charge cycle and tops up the batteries quicker and more fully.
Improved high-precision hub, with tighter blade fastening tolerances, for perfect blade alignment and whisper-quiet operation.
Improved molded urethane isolator pad, which fits between the pole and the collar. Molded in "cap" allows it to stay put during assembly.

The great performance of the original MK450 remains. The above changes are incremental improvements designed to improve start-up speed, ease assembly, resist corrosion, and improve real-world output. The MK4+ is truly a world-class micro wind generator.

Tired of talking to non-technical vendors that don't understand the nuts-and-bolts of what they are selling? Give our technical rep, Jeff, a call directly at (864) 275-7837 to answer any questions. Read on to see what really matters when considering wind power for your boat.

Why Consider the MarineKinetix Wind System?

The MarineKinetix Wind Turbine System is simply one of the best performing small wind generator system available for marine use. That is quite a boast, considering all the small turbines out there with catchy names, and bigger advertising budgets, but read on to find out why we believe you'll soon agree.

The MarineKinetix MK4+ is a simple to install, hands-off, super-quiet wind-energy production system made especially for the marine environment. This high-output, low start-up-speed system utilizes the best of European wind-science in its design. In addition to its leading-edge high-output dual-bearing 3-phase permanent magnet generator, it also features world-class aerodynamic efficiency with its carbon-filled aero'coustic rotor blades, which have been optimized for high torque, low rotational inertia, and exceptionally quiet output. These features, coupled with the included "hands-off" microprocessor-based charge-controller, and its exceptionally low yaw-error, make for what we think is the best marine wind generator system on the market. See why below.

The MarineKinetix MK4+ wind turbine system is a leap forward in wind turbine science. It makes the intelligent compromise between low-speed start-up and high-speed output, all at a realistic and cost-effective price.

A complete 400 Watt Wind System (includes generator and controller)
1330mm Blade Diameter (1.3M) - Swept Area = 1.39 Meter
Weighs only 17 lbs., about HALF the weight of certain competitive designs, without compromising performance thanks to a magnalium body, an asymmetrical rotor, and high-energy-density Nd2Fe14B rare-earth magnets
Lightweight 300g 20% Carbon Fiber Polymer Composite blades
Available in 12V, 24V and 48V designs
Compatible with VRLA, Gel, AGM, Lithium, and Lithium Iron Phosphate (LiFePO4)
Industry Standard Mounting - Mounts to 1.5" Schedule 40 pipe (1,9"OD), or 48-50mm OD tubing
Double marine thermoset powder-coat finish, over a DACROMET self-healing aluminum-zinc nano coat
5.8 knot start-up speed (begins producing power), 6.7 knot cut-in speed (begins charging 12V/24V batteries)
Aero'coustic 20% Carbon Polymer Blades
Super-silent - LAeq 35dB at 5M at 10 knots (about the same as a running fridge)
Direct drive, 3-Phase dual-bearing AC permanent magnet synchronous generator
Neodymium Iron Boron (Nd2Fe14B) permanent magnet synchronous design
12 pole rotor, with bread-loaf magnet profile, and asymmetrical pole-shifted magnet placement, for low cogging torque
Automatic back-EMF braking at full charge (or 40 knots overspeed protection)
IU PWM Charge Control Profile with hysteresis braking
Microprocessor controlled auto set-point for AGM, Gel, VRLA, Flooded, Lithium, and Lithium Iron Phosphate (LiFePO4)
Requires no diode packs, diverters or external resistive loads
Over-charge, over-current, and automatic over-speed protection
Integrated heavy-duty yaw-axis slip-ring, allowing continued >360° limitless rotation
Simple installation, and user-serviceable components
Includes micro-processor charge controller with "at-a-glance" LCD charge, voltage, amperage and wattage status
Fully compatible with existing solar installations (no conflict with other existing charging sources)
3-year limited warranty, and 30-day 100% satisfaction guarantee
Full lifetime tech support by phone or email with purchase

What is included in the Wind Generator kit?

MK4+ Wind Generator
Smart Charge Controller with integrated performance monitor and stop switch
Blades (x3) with SS blade mounting hardware
Hub, with mounting nut
Snap-on molded plastic nose cone
SS Hardware to mount clamping collar to your pole
Silicone rubber isolator (goes between pole and mounting collar)
Assembly allen key tools
Instructions

What installation accessories and spare parts are in-stock and available from Marinebeam?

50A Resettable Circuit Breaker
Pole Mounting Hardware Kit
3-Piece Pole Mast
10/3 Marine Cable
Spare Parts

What is the wired Remote Stop Switch Connector option?

While the controller already has an integrated stop switch --accessed with the front panel buttons-- some customers who will have limited access to the controller location may wish to mount a secondary stop switch in a more accesible locaton. So, this option includes a two-pin connector, which attaches to a port on the bottom of the controller, and allows you to run your small-gauge wiring to your on/off toggle switch. The switch and extra wiring are not included, but this is a very low voltage and low current control signal, so a light gauge wire (18-22 AWG) is sufficient. For more sophisticated systems (like off-site telemetry systems) a relay can be used to remotely actuate the brake.

Details About the Unique Marine Kinetix Technology:

Our solution is a systems-approach to wind-energy production on-board. The MK4+ system couples several forward-thinking ideas into one "wind-system" which is easy to install, affordable, and maximizes energy production. We did this by first starting with a low-friction, high-energy-density 3-phase rare-earth magnet rotor design, which came from concepts and materials used in leading-edge green-energy vehicle research. The Neodymium Iron Boron (Nd2Fe14B) permanent magnet rotor uses patented technology licensed from Sumitomo/Hitachi in Japan. This is the same type of PM rotor design used in the AC synchronous motors in the Chevy Volt and other electric vehicles. The rare-earth magnetic rotor is a key to its performance and low noise and vibration. We now utilize an asymmetrical pole-shifted rotor design, which is a advanced method that replaces the heavy mass and cost of older skewed rotor designs, while providing the same advantage of reducing the cogging torque, and improving low speed performance. We coupled this super-efficient machine with a biomimicry-inspired carbon-fiber-filled blade set, which makes for super-quiet performance while improving overall aerodynamic power.

The results are a turbine that outperforms others in start-up speed, output, and noise. While other systems are idle, the MK4+ is generating. While other systems are disturbing the peace, the MK4+ is virtually silent. While other systems are struggling to charge, the MK4+ is topping off.

What are the important factors in wind energy production?

Physics dictates the basic performance of all wind generators. In fact, the power available to any wind generator is a function of the square of the diameter (swept area of the blades) and the cube of the wind speed. The ability of any specific wind generator to the capture wind efficiently depends on the length of its blades (its swept area) and its Tip Speed Ratio. Tip Speed Ratio refers to the speed of the tips relative to the speed of the wind. If the blades spin too fast relative to the wind, they begin to begin to look like a solid disk to the wind, and air piling up in front of the blades effectively blocks the wind behind it. On the other hand, if the blades spin too slowly, much of the wind passes through the gaps between the blades, and the energy is lost forever. So, swept area and blade design are the most important areas which the wind generator manufacturer can control. While the MK4+'s blades are only 8 to 9 inches longer than the typical blade, they sweep as much as 40% more area than the competition. With a nearly perfect tip speed ratio due to the computer-modeled and simulated blade design, and the impedance load-source matching of the controller, the MK4+ has a higher energy capture compared to most other designs.

Because of the cube relationship of wind speed to power production, wind speed is absolutely the most important factor in wind energy . There is no getting around the physics of that. There is 27 times more power in a 15 knot wind than a 5 knot wind. The key takeaway here is that regardless of the technology, you need good wind to get good performance from a wind generator .

What affects the ability to maximize output power capture shown above?

Wind generator power is dependent on wind speed, battery acceptance rate, and applied load , so a variable load and a discharged battery was used to characterize the absolute capture power for the data above. As the wind increases, your wind generator will already be charging full-time, and the battery bank's acceptance-rate, in amps, will decrease as the battery charges and its voltage increases. So, it is important to understand that by the time the wind is blowing 20 knots or more it is likely your batteries will not be capable of accepting the full amount of amps that any generator can provide. This is good. It means that your batteries are reaching a full state-of-charge, and that you have the headroom in power to cover any other loads as they arrive, without further discharging your batteries. At the end of the day, it is best to think of a wind generator as a free-energy variable power source, whose output changes day-to-day depending on the available wind and the presence (or absence) of downstream electrical loads that it requires to generate power.

Read the following pages to learn about the MK4+, and view the video below to see how it performs against a much more expensive wind generator at very low wind speeds.

Our Integrated "Wind-System": Many popular marine wind generators are essentially sold in kit form, with the user left to decide what method of control they need to get the power into their batteries effectively. Alternatively, some turbines have an included charging set-up, but offer what is essentially a simple automotive voltage regulator and a load diverter. This can be a real problem for those wanting to optimize charging and protect their expensive batteries. It is not enough to just generate efficient and effective power at the generator head. It is just as important to get that power effectively into our battery bank, and to regulate that power based on the battery's specific demands for voltage and current throughout its charging cycle. By use of an IU charging profile, the system not only can be more efficient, but can also significantly prolong the life of the batteries by preventing overcharging. Typical load diverter type controllers can only charge your battery to about 80% State-of-Charge (SOC). This partial cycling is particularly bad for your batteries. Combining the Low Start-Up Speed "Tortoise Approach" with the High-Power "Hare Approach": Having seen both real-world performance in various anchorages around the world, as well as published performance testing over the years, we realized that the best approach out there on the "real water" was to apply leading-edge technology to each component of the system to find an intelligent compromise between the Tortoise Approach and the Hare Approach to wind energy production. A small wind-system that is capable of making power in low wind speeds can take advantage of a long day with low wind speeds by putting small amounts of power into the battery consistently throughout the day and night (the Tortoise Approach). On the other hand, a larger system can take advantage of big gusts or heavy wind by making tons of power very quickly (the Hare Approach). The perfect solution for us cruisers would be a two-stage turbine that could be the Tortoise in low wind speeds, or protected anchorages, and could be the Hare in a high-velocity wind environment. By leveraging leading-edge technologies to make incremental efficiency improvements in each of the discrete components of the wind system, we achieved a "sum of the parts" that meets our goals for an ideal marine wind system in-board. We believe it is the best marine wind generator on the market for those sailors wanting a high-quality, hands-off, high-output, and super-quiet system. Our real world data and feedback from our customers backs up that claim. Read on to see how we did it. The Blade Set: We have found that the practical key to consistent production on-board is to start with a large 1.39 meter swept area, and then to apply leading-edge technology to the blade set to extract the maximum amount of energy. Swept area is the most critical aspect of energy capture, and the bigger the swept area, the more power, period. Blade length defines the swept area (Area= π r 2 ), and typically the longer the blades, the stronger and heavier they must be to withstand the exponential increase in torque. The MK4+ solves this issue by using a unique 20% carbon fiber molded blade that is not only long and rigid, but extremely light as well (<300g). This allows us to produce a blade that is up to 9" longer than the competition, but it weighs much less, and sweeps up to 40% more area.

We also focused on the airfoils to get a super-efficient, super-quiet, Aero'coustic blade that gives exceptional power while maintaining low-speed start-up capability. This way the turbine can take advantage of all-day energy production, but also can generate more serious power when the winds pick up. It doesn't do much good to have great potential generating capacity if the blades never turn in the real world. Compare our start-up and output to the competition, and you will see the distinct advantage. Details of the Design: The blade and tail design focuses on several key strategies:

Low Start-up Speeds
Very Low Rotational Inertia
Very Low Noise at Optimum Tip Speeds
Very Low Yaw Error
Optimized Tip-Speed Ratio (the ratio of the speed of the tips to the speed of the wind)

While our carbon-fiber reinforced blade set has an extremely low rotational inertia, a strong and lightweight blade is only part of the story. The starting torque on a wind turbine is generated in the blade area closest to the hub, while the power producing torque is produced in the blade area closer to the tips. By use of German-engineered computer modeling and simulation, a variable blade profile was produced that can react quickly in low wind speeds, yet produce high torque and optimal tip-speed ratios at high speeds. The blades are produced in a solid-model-patterned single-cavity injection-molding tool, so that each blade is identical in weight and profile. Using a 20% carbon-fiber filled polymer makes the blade very light, durable, and repeatable. Lightweight blades have a low rotational inertia, which is critical in wind-energy production in the real world. Low rotational inertia allows the blades to accelerate more quickly, which means they can spin faster in lower wind speeds, therefore keeping the tip-speed-ratio (the speed of the tips vs. the speed of the wind) more constant. Operating closer to the optimum tip-speed-ratio during gusts also allows the turbine to improve energy capture from these sudden gusts as well. Another way to increase aerodynamic efficiency --and to reduce noise on an airfoil blade-- is to manipulate and control the lateral airflow over the foil. Of course, some of the best engineering solutions often come from mimicking what is already found in nature. Whales and certain fish have amazing hydrodynamic efficiency and stealth through the use of tubercles , or raised and slotted sections on the leading edges of their fins. Our blades likewise use biomimicry-inspired riblets along the leading edge of the blades, which help the airfoil to create more power at lower speeds, and to operate more efficiently in turbulent air streams. These Aero'coustic riblets, also prevent the air from traveling down the blade edge and "vortexing" off the blade tip contributing to tip noise. The noise you hear from most wind turbines is the sound of wasted energy. How quiet is it... really ? The MK4+ is extremely quiet, and we have never heard one quieter. In fact, it measures only 35dB at 5 meters in 10 knots of wind. At 15 knots, just a flutter, but no tip noise. As the wind builds the flutter noise will increase. Above 30 knots, everything exposed to the wind at that velocity will generate some noise, including the MK4+. To get an idea of how quiet it really is, just watch the video below. Note that the video was shot with a CMOS rolling-shutter camera, so the blades appear to be turning slowly, while in actual fact they are turning at several hundred RPM. Video compliments of customer Hayden Cochran on his Island Packet "Island Spirit":

What is Yaw Error, and why is it so important?

wind-solar-streetlight-controller-with-buck-system.jpg-200x200.jpg

This is quite different from most of the other, and more expensive, 400W generators. The typical marine wind generator charge controller uses 50 year-old technology, which is simply a load-diverter switch, which, upon reaching a set-point, diverts 100% of the energy to a set of resistive elements (essentially heater coils). So, when the battery reaches its dumpload set-point it isn't actually fully-charged, and this type of Partial State of Charge (PSOC) cycling damages the battery by reducing its capacity, and sulfating the battery plates. They can't fully-charge the battery because they have no way to dump only the excess power produced, while continuing to top up the battery. They can only dump all of it. The best scenario would be to have a way to progressively dump power so that the batteries could be fed with only the power that they need at this final stage of the charging process.

The controller is very compact (5-5/8" H x 5-7/8" W x 3-1/4" D), fanless, and is designed to be bulkhead mounted.

It has the following additional features:

(1) Full monitoring capability (Volts, Watts, Amps), no additional battery monitors, shunts, panels, or displays needed (2) Backlit LCD display with clear graphical readout (3) Manual Brake deployment via keypad, so no additional stop switch is required (4) Battery charge level indicator (5) External load control (for managing lighting, etc)

Unlike some other popular marine wind generators which have internal controllers, there are no on-board electronics in the hot and salty elements, and there is no need for additional rectifiers, heat sinks, stop-switches, large resistive loads, or ammeters. It all happens automatically and safely within the charge controller. It even protects from over-charging and under-charging. It is truly a hands-off charging solution

Maintenance and Warranty: The MK4+ is designed to provide years of trouble-free service out in the elements, and has a 3-year warranty against defects in materials or workmanship. We specified a simple and rugged mechanical set that uses very few parts, is easy to maintain, and will stand up to the rigors of the marine environment. Unlike most single bearing automotive alternator-based designs, our dual low-friction rotor is supported by two low-friction bearings to provide long-life and easy start-up. The unit is easy to disassemble, understand, and maintain. The body is made of a lightweight magnesium and aluminum alloy, which is pre-treated with a zinc-aluminum nano-coat, and then a double marine-grade epoxy powdercoat to resist oxidation and corrosion. See our warranty details in the manual for full terms and conditions. The MK4+ is bluewater tested by full-time cruisers, and like all of the Marinebeam products it is backed by the best technical support and warranty in the business. Be sure to look at the various customer installation picture above to see some of our installations around the globe.

Interesting Links

Click here for our Frequently Asked Questions (FAQs) document.

Link to download PDF copy of installation manual (V2.2)

Link to download PDF copy of controller manual (V2.1)

Should you have further questions, feel free to contact us by phone or email. Jeff, our resident MK4+ technician can be reached M-F 9-6PM at (864) 275-7837. Or you can reach him by email at [email protected]

Product Videos

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22 Reviews Hide Reviews Show Reviews

Wind generator.

Posted by Chris S/V Waterwitch on 14th Oct 2024

Super happy with this purchase! It is everything I hoped for. Tech support was super helpful with my install. Smooth, quiet, and powerful. This unit is a work of art!

wind generator

Posted by keith on 9th Oct 2024

didn't know how worn out my old one was until i installed my new one.

Great Unit with Great Service

Posted by Jean on 5th Sep 2024

I had this wind generator running for the past 6 years at the top of my mizzen mast on my sailboat as good and reliable as the first day i put it up there. Sitting at the top of the mizzen mast i needed to install a unit with low maintenance as i can’t easily climb up to the top. Summer, winter this thing is running non stop for the past 6 years without a single issue and performance is very good. I use to have the Air Breeze which i don’ miss at all. If you are looking for a great unit at a great price don’t hesitate you will be very pleased with this wind generator. And as an added bonus you will get outstanding customer services.

Quiet, but needs > 15 knots wind....

Posted by John on 16th Aug 2024

Nice, quiet wind generator but needs at least 15 knots before it produces useful output. This is not a criticism as pretty much all wind generators need this much wind to be useful. The "Very low startup speed" sounds great but in reality all that's happening is that the blades are turning at low wind speeds - there's no power coming from it ? Below that all it does it light the small LED under the body ? The controller is better than some but does not offer "MPPT" charging for the solar input. It's origin is in controlling street lights and that shows in the menus that offer not so useful options to control lights. The only other problem is that either the controller or the generator are electrically noisy. The electrical noise manifests itself as a harsh buzz (on SSB/HF radios) that charges according to wind speed. It can be removed by putting the electrical brake on but then, of course, it produces no power at all! All in all it doesn't make the difference I was hoping for unless you get > 15 knots apparent wind. Plus points are that it is quieter than most, is a very good price and seems well engineered.

sku: WR-10-3G

Round profile 10/3 marine tinned cable.

sku: CB-50A-42

50 amp manual reset circuit breaker.

Shown here are all of the wind generator pole mount components that are included in this kit - all hardware is 316 SS.

sku: MK4-MOUNT

Marine wind generator mounting pole hardware kit.

sku: BL-MK-4+

Replacement blade for marinekinetix mk450 or mk4+ wind generator.

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