How much electrical grunt

[too_tall 15]

BTW I think $5/l will happen sooner rather than later then carry on up.

 

I doubt that diesel will get that expensive in the foreseeable future. Simply put, bio fuel, which is much easier to do in a diesel than petrol engine, is economically viable once the oil price reaches $100US/barrel. And at that $100US/barrel our diesel prices hover around $1.50 -$1.65 depending on the strength of the dollar and what taxes have been put on the fuel.

 

Should fossil fuel diesel become $3 per litre, there will be a MAJOR shift on arable land toward producing fuel as opposed to food, because what was viable at 1/2 the fuel RRP suddenly will show a massive margin. There is not really a "peak oil" point to consider with this concept, other than, I guess, the competition for food vrs oil.

 

I think that whilst Wheels has been a little to keen with the requirement for 50hp to get out of the marina, he has not been too keen with the consideration that engine power is great for boat handling if something goes a little pear shaped, or if there is considerable current to deal with... Its a shorter term thing, in general, requiring significant power, but it is very much handy to have.

[Guest]

Yes they are good to have but I recall reading that all we need is one hp per ton! Now I think mostly 4 hp per ton and no one wants less than hull speed from their motor.

[rigger 47]

On the hp required.

It is not as simple as one HP per ton, or is that tonne.

I have read all sorts one site states 1kW per 300kg.

 

Consider the windage of the vessel.

What current will you motor into?

 

My 3.2tonne yacht went ok with a 5hp, but the 8hp was not struggling in a good chop like the 5 did. I would hate to have had to make to weather relying on a 3.2HP outboard.

 

I'll try and dig out some info on power versus wind and tide, might take a day or so to find it.

[wheels 543]

There has been time where I have made way of only 3kts into a ruff head on Sea and I have 130Hp.

It's all very nice having the idea that you only need enough to sneak in and out of a Marina, but for many of us, we don't always have the time to await the breeze. Example, Shanson and I ended up motoring all the way to the BOI. No wind. We then motored all the way back with a headon Southerly. So there are times the motor does become more important than the mere basic one can get away with.

[Guest]

Its meant to be a sailboat Wheels

[DrWatson 381]

You guys with your diesels and electricity. I'll be going for something much more eco-friendly...

 

 

The harness this little kid is using would do the trick. Just lasoo myself a few friendly dophins and we'll be right as rain...

[Guest]

Great idea DR, I was also thinking of pedals for the kids and wife!

[DrWatson 381]

Actually, I'm more concerned about what will happen to poor Mary when that dopin decides it wants to go a little deeper...

 

Pah! Never let the reality of biology quash the joys of photoshop...

 

 

(sorry bout the thread drift)

[Grinna 2]

So today we walked up and down a few fingers at GH (they leave the gates open for people like us) and stood alongside all the wind generators we could to guesstimate the noise output. Early indications are that more blades with less diameter is quieter than fewer blades and greater diameter - discuss

 

Not that simple. Different designs produce different noise and it's not ALL to do with blade design. Some blade designs are quieter than others and small alterations of the blades can make big differences in apparent noise. In my experience its the changes in blade noise that are the most annoying. Some wind generators spin up to a certain speed and then the overspeed protection kicks in and the noise changes and sounds like a banshee wailing. Others don't do that.

 

You need to come down on a windy day and listen to our wind generator Squid (bring a bottle if you like .... it helps the noise assessment process ). That's one reference point. Find another type of wind generator and listen to that for a while ... etc, etc.

 

Other things to consider are:

 

Generally you try to anchor where the wind is reduced .... that means your generator isn't going to see so much wind and therefore won't make you lots of power.
 
Wind generators, like alternators, belt out the ergs and stuff them in your batteries hand over fist when your battery charge is low but as the battery charge gets up it seems to be harder to cram all the ergs in or something because the rate at which they charge your batteries reduces ... it takes a long time to stuff the last few ergs into your batteries.
 
Wind generators tend to come into their own on passages where the apparent wind caused by actual sailing is then converted into ergs that get crammed back into your batteries. So wind generators on passage can keep up with the erg supply required by chart plotters and autopilots and things (maybe) to reduce the number of ergs you need to put back into the batteries.
 
Wind generators, unlike solar panels, can work at night ..... if its blowing and if they don't make so much racket that you turn them off so you can sleep.
 
Wind generators generally don't seem to make as much power as you might expect them to.

[Guest]

Could a few people who have them chime in and tell me what output they get on passage and at anchor??? Please?

 

My empirical solution to how much power we need to generate is to move aboard and see if the batteries go down. If so we need more generating ability. Repeat.

Also the first step is switching a bucketful of lights for LED's.

[Island Time 1,246]

That's difficult CO, as it depends completely on conditions. I've had 2 wind gens. The first was an air-x marine. Max output 400w in theory. It would produce about 30 amps Max on occasion, but the tolerance between Max output and switch off speed was not huge. Also, once at the auto brake/switch off, it roared so loudly you could hear it over 50 knots of wind! However, I liked it, as, on passage it normally produced 10 -20 amps depending on conditions. That was enough to run everything aboard. This unit auto brake exploded in 50 odd knots off cape Melville in ausy, so;

I replaced it with an Air Breeze. It starts generating at a lower speed, but never achieves the output that the Air X did. Max I ever see out of this is about 15 amps. Standard, it is a lot quieter than the Air X. I've replaced the blades on it with the blue ones from silent wind generator, as I had on the old Air X. This is by far the single biggest improvement you can make to them. Lower start up speed, and much quieter.

If I was to consider a new unit now, I'd buy the one from silent wind generator - it did not exist when I bought mine. They are a bit pricey, but well made with great performance.

Output averages.

You have to look up the specs from the manufacturers, for the various wind speeds. Graphs work best, so you can do a direct comparison.

Remember also that here in NZ we tend to anchor out of the wind when possible, where as in the tropics some breeze in the anchorage is better. Therefore start-up speed is very important.

[wheels 543]

Of course the output is also dependant on where the battery bank is floating at. You can only ever get max output if your bank is able to soak up the current. All Wind genny's require a substantial amount of wind to create their max output.

I don't think Solar alone is the best, nor Wind alone. But the combination of both works well, with the ability to top up if required with the Diesel Genset.

[Grinna 2]

All Wind genny's require a substantial amount of wind to create their max output.

 

According to the documentation that accompanied our wind generator, its designed to start making current at 8-10 knots (from memory) and makes max current at around 20 knots but then just continues to make max current from there on up in terms of windspeed. How many ergs its able to stuff into your batteries though depends on how much room you've got left in them to store more ergs.

 

I can't really give you any performance figures for it because we've not done any long passages since we've had it up and running (or much of any cruising to be honest). With the batteries close to fully charged the wind generator doesn't seem able to add much. I'm told that when paired together with solar panels the wind generator tends to add more than the sum of the parts (if that makes sense) and comes into its own on long passages .... this remains to be seen in our case.

 

For the record our wind generator is a German designed and built unit called SuperWind.

 

One other thing to bear in mind is that wind generators do require a small amount of maintenance from time to time. The design of the SuperWind allows you to change brushes without pulling the unit apart ... very clever.

[Island Time 1,246]

The superwind is a pretty good unit. Its a little higher startup speed than the air breeze or silent wind ones, requiring 10 knots to produce 1 amp at 12 v. Full output 29 amps, at just over 24 knots. The new blades they have made only produce about 1/2 the noise of the old ones - worth a retrofit if you have the old ones....

[RedLine 0]

Had an Air-X Marine and two 100W solar Panels on my cruising boat. You need both if you want to minimise on running the engine. I found you could spend up-to 5 days at anchor without running the engine for charging. That was running a decent sized fridge freezer, and a the usual lighting, odd bit of laptop or LCD TV use.

 

But if it was overcast & not windy for a few days, then it changes. As everyone else says on passage wind generators work well when reaching & the apparent is up. But for long downwind passages the apparent is low, and they don't go so well, but mixed in with solar its usually enough to run the autopilot/plotter etc.

 

Best thing is a battery management panel that shows AH in/out of your house batteries from this you always have a good idea of the state of charger of your batteries.

[wheels 543]

Re noisey blades, I spent a little time sanding the surface and edges to get rid of little bits and that made a big improvement to noise....er....less noise that is.

[Island Time 1,246]

Yep wheels, I sanded the blades on my Air X, and it made a significant improvement to noise levels.

 

It's interesting to note that the Silent Wind blades have a ridge on the Leading edge, and a three line pattern in 3 places, also on the leading edge. I guess it is something they found in their wind tunnel testing that helped reduce noise, harmonic balance or increase performance. I see the new Superwind blades also have a leading edge ridge.

 

If anyone has blades with a leading edge ridge, I'd suggest NOT sanding them - they are designed like that for a purpose. However, if the blades are not smooth in finish (not in design as in the ridge), as the original Air X black blades are, it is worth sanding them to the best finish you can.... IMO, and in my experience. You may find something different!

[Grinna 2]

Squid, have you seen this review of several wind generators and their relative performances?

 

http://www.naviclub.com/Test_comparatif ... marine.pdf

 

or this comparitive assessment

 

http://www.windenergy.com/sites/www.win ... onthly.pdf

[Guest]

I think what you need maybe a 'Ion Generator with Plasmacluster technology'.

[wheels 543]

KM and I have been learning some big words this week.