As with any mechanical device you are researching, it is a good idea to learn some of the terminology associated with the product. Not all of us know the meaning of 'swept area', 'power capture' or 'yaw error'. Likewise with the electrical side of the wind generator. Learning about output wattage, amps, and microprocessors can seem like a daunting task, but it is necessary to know these terms before you shell out hard earned cash for a quality wind generator.
Some features of wind generators, such as weather-proof coatings and low-noise operation, are common to all makes and models. The use of rare earth elements like Neodymium, (Nd2FE14B, used in magnetic rotors), can add hundreds of dollars to the price of some of these wind generators, but defiantly do add to the overall dependability of the unit.
Some of the more desirable things to look for in a wind generator are:
- Ease of Operation
Also known as plug-n-play, the simpler the set-up, the better. Choose a model that has built-in controllers, that ???makes for less complicated wiring runs. A remote monitor is handy to check on the status of the charging system without crawling into the battery room, or looking up to see if the blades are still turning. If you are ordering your generator and having it shipped, ask your salesman to be sure it has detailed assembly instructions and perhaps an owner's manual in either DVD or booklet form.
- Low Cut-In Speed
Wind generators work best when the blades are humming along in 20 knots of wind, but that's not always the case. Low cut-in speed means your batteries are getting a charge in the lightest of airs, if only a trickle charge.
- Auto Brake
If you happen to be ashore when the wind kicks up, you don't want your turbine to spin wildly out of control. Some generators feature a type of automatic speed governor that slows the blades down before they self destruct. Back in the day, you had to pull down on a cord to apply the brakes, then climb up the mast or mounting pole and manually tie off the blades.
- Over-Charge Protection
A 'brake' also kicks in when the batteries are nearing or at full capacity, to prevent overcharging. Some controllers slow the rotation of the blades, others 'dump' the excess power generated through a resistor and heat sink. Wiring an in line reset-able fuse can prevent damage to your batteries should a malfunction occur within the charging system.
If you are one of those part-time sailors who cruises for a few months, then dry-docks your vessel for the off-season, choose a light-weight portable wind generator you can set up at home to off-set your electric bill. In case of a hurricane or other emergency when there is no power for days at a time, your wind generator can power cell phone chargers, laptops and rechargeable battery stations. Removing your wind generator and locking it away in the cabin also deters thieves. Portable wind generators that are light can be mounted on higher surfaces without worrying about upsetting the balance of your boat. The heavier the generator, the lower it should be mounted, allowing for safe passage under and around those spinning blades, of course!
It is also a good idea to know your boat's needs and desires before settling for a low cost, low output wind generator. Everything that runs off a battery, including the DC to AC inverter, should be listed, along with their amp/hour draw, to determine how much power you will need to generate. Compare your toys with your reserve amps of your house battery bank. Do you just have a few LED bulbs and a masthead light to run at anchor? Then you can get by with a low output generator. Are you keeping a keg cooler, stereo, disco ball and Netflix going all night? When underway, are you powering SSB, weatherfax, VHF and radar? Then you need a rack full of batteries, and a wind generator with the capacity to keep them topped off.
Speaking of batteries, make sure the wind generator you purchase can charge all the different batteries available. Even if you only have wet-cell lead/acid marine batteries now, you may upgrade to AGM, Gel or even LiFeMgPO4 (Lithium Iron Magnesium Phosphate) batteries in the future. Some wind generators and their controllers are not advanced enough to charge these newer power sources.
Unless you are well versed in the application of electrical theory and DC current, you probably don't know much about wire size and current loss. Even the best wind generator will not function as advertised if the power can not get from the blades to the battery. If you have a long run from your generator to the battery bank you intend to charge, make sure your wires are correctly sized to prevent line loss from resistance and over heating. Most installation manuals will have a wire chart included for DIY installations, and there is always a help line to the manufacturer.
Here are four out of the dozens of wind generators out there that have positive reviews and some of the most desirable features.
1.) Superwind 350, 353
This German manufactured turbine features their patented Auto-Feathering Overspeed-Avoidance System. This is basically the same method a helicopter uses to gain lift, and settle back down. As the wind speed reaches 25 knots, the blades 'feather', or dump air, making them less efficient, and slowing their speed. As the wind lessens, the blades re-pitch, becoming more efficient. This action delivers a steady flow of charging current to the batteries, without going into a shut-down mode to prevent overcharging, as some models do. The Superwind generators also can be combined with solar panels and conventional diesel generators. The Superwind generator family also uses a brushless A/C stator for maximum control of noise and radio interference while the unit is producing power. Two sets of bearings in the 350 make for smoother operation and overall longer bearing life. Available in 12v, 24v, or 48v outputs. At close to 30 lbs, these units are well built and dependable. With a price tag right around $2,700 for the Superwind 350 kit, you can expect German Engineering at it's finest. https://www.superwind.com/superwind-350-353/
The Automaxx line of wind generators comes in 12v, 24v 48v models, in outputs from 400w up to 1500w. Survival wind speeds are listed at 110mph, but we hope you would never have to put that spec to the test. With very low cut-in speeds of less than 6mph, you will get charging amps on the slightest breeze. All their models come with auto-braking and manual braking system protection, over charge and over-speed protection. The 3600 rotation of the power head keeps the unit into the wind, even when you are docked or med-moored. Simple plug and play setup with an internal MPPT (Maximum Power Point Tracking) charge controller makes the DB400 an easy to install unit, while their other models feature a remote charge controller. Works well when combined with solar chargers. At 16.75 lbs., it is lighter in weight than the Superwind, and it's seven times less expensive at around $400.00 for the DB400.
3.) MarineKinetix MK4
One look at this brand's marketing home page is like an advanced course in wind generator physics. The list of specs for it's models is truly impressive. Not only do they boast all the latest technologies featured in their product, they explain all the scientific jargon they use in terms us simple sailors can understand. They have been providing wind generators to the sailing community for 8 years now, and have a devoted following.
If you need to know the difference between $400.00 wind generators and $1,800 units, check out the product overview section of their website.
The MarineKinetix brand has the the industries best 3 year limited warranty, so they must be pretty sure about their product.
The 12v models of this brand are currently out of stock, due to parts supplier back-orders, but if you are in the market, there are plenty of 24v and 48v units in stock. https://store.marinebeam.com/marinekinetix-mk4-marine-wind-generator/
4.) Rutland 1200
One of the quieter wind generators out there, the U.K. made Rutland has a long track record of dependability and customer satisfaction. A manual switch is used to stop the blades when high wind is expected, there is no auto-brake. The Rutland can be combined with solar panels up to 20A, and can be also be used with deep cycle gel or AGM batteries, and there is a remote digital display available. One of the Rutland's best features is it's Tri-namic Blade profile design, which achieves low start-up speeds, silent operation in any wind, and maximum power transfer from wind to rotor. Overall good performance and features for the $1,600.00 price tag. https://www.emarineinc.com/Rutland-1200-Wind-Turbine
Wind generators are a fairly common sight in most anchorages, and towable generating devices have been around for some time. The DuoGen-3 combines the two into one multi-use charging system. Underway, the high strength carbon fiber mast is lowered down to submerge the blades. At anchor, the unit functions like a typical wind generator. The results are impressive. In the water mode, the DuoGen-3 generates 200 Watts @ 16 amps cruising at 8 knots. Wind generators do not do well sailing downwind, so this may just be the answer. Available in 12v and 24v versions. Charging regulators are not included, so monitors and controllers have to be matched to the unit and sourced locally. https://eclectic-energy.co.uk/
Choosing the right wind generator for your vessel should be a pretty straightforward process, once you have an idea of your needs, the area you will be cruising in, and how long you expect to be 'off the grid'. If one generator is simply not enough because of the size of your battery banks and the load you put on them, you may need to purchase a pair of turbines. Customer support and availability of parts may be the determining factor in your purchase. Talk to other wind generator owners, and get a feel for what they have experienced with their current of former wind generators.