Derek
To give a you sensible answer it would help to know what kind of sailing you do, as different scenarios may lead you to different conclusions. First question: I notice that you say you’re based in Southampton; is that in a marina berth, or a swinging mooring somewhere? Second, do you spend most of your time on long passages with limited access to shore power, or do you (like most of us in the BOA),take mainly relatively short trips with the occasional long one thrown in? If yours is the second scenario then frankly I wouldn’t bother with a wind generator. I had one (a Aero4Gen) on the boat I had before I bought my Bav32 in 2002 and frankly found it of limited help, for a number of reasons which I’ll spell out later. In the context of running all the services you mentioned, I think you’ll find that your money would be far better spent on a good quality multi-stage mains powered battery charger, a ‘smart’ regulator for the engine alternator and finally a decent multi-function battery monitor. All this is based on the assumption that your batteries are in good condition in the first place! My experience over eight years cruising in the Bav, mixing Solent based passages occasionally night-stopping at anchor and some marina stops, along with much longer (cross Channel and long hauls to the west country etc) is that the kind of pwer management set up that I’ve suggested is more than adequate, with just a single 180AH service battery. I run all the usual things on my boat: chartplotter, radar, radios, nav instruments, a very power hungry autopilot, fridge, heater etc. As long as the battery status is monitored carefully then I’ve never had any problem keeping it charged, provided the engine is used a bit and I can plug into some shore power every few days.
My experience with the Aerogen was mixed. Although it was a reasonably reliable piece of equipment, in my opinion (and I’m sure others will disagree…..) there are disadvantages. First of all the Aerogen only starts to give a reasonable output of around 3 or 4 amps in winds of F4 and above. It, like all fan driven generators, is quite noisy and the blades can give you a nasty cut on the head as I’ve found to my cost! They also break fairly easily if you catch one on a pile or whatever. Mounting the unit can be a problem as it’s quite heavy and needs plenty of clearance all around the fan, to reduce the chance of something hitting the blades. The mounting needs to be fairly rigid to keep vibration to a minimum; if the fan is even slightly out of balance your boat will feel like driving a car with one wheel out of balance! My main concern is with actually charging the battery. As long as you start with a fully charged system then the genny will do reasonable job of keeping it topped up, but don’t expect it re-charge a heavily discharged battery quickly; on passage it would certainly help in keeping the system topped up but running your autopilot, radar, instruments and so on would still probably result in a net discharge. Another issue to consider is the generator’s voltage regulator, which can get very hot when the genny is trying to charge an already fully charged battery and the excess current is dumped into the heat sink. It must be located in a well-ventilated area!
Returning to the original questions perhaps you can see my reasoning. If you spend most of the time away from civilisation and are relying on your own resources then maybe a wind genny is the way to go, provided you don’t mind the noise and accept the risk of decapitation, but don’t expect it to provide all your charging requirements, unless your pocket is deep enough to afford one of the very expensive, high tech machines favoured by blue-water liveaboards, sailing in more exotic climes!! However, if you spend most of your time within reasonable reach of a shore-power socket then I think there is a better alternative. When I was sailing my Aerogen-eqipped boat I invariably ended up securing the fan on passage, if only to get rid of the noise and vibration. Finally, I’ve had no experience of their use but if your main concern is keeping the batteries topped up while you’re away from the boat have you thought of a solar panel?
Hope this helps!
Regards
Ian Culley, B32 ‘Another Fantasy’
