Camper Mounted Wind Generator

[SChandler]

Just saw this in the latest Truck Camper Magazine newsletter: http://www.truckcampermagazine.com/news/new-product-free-spirit-energy-wind-generators. Manufacturer's website is here: http://www.freespiritenergy.com/. I have no affiliation with the product, never seen or used it, etc., but thought some of you might be interested in it. Looks like a decent alternative to solar or could be used to supplement a solar system for battery maintenance.

 

[Funrover]

I really like that idea, This would be perfect on my current project.

 

[dwh]

Eh...I'd be leery.

It's well known that "small wind" (i.e., small wind generators) don't put out much. The formulas are also well known:

http://www.power-talk.net/swept-area.html


It's also well known that all small wind companies overstate what their generators actually produce. (The one exception to that which I'm aware of is TLG http://www.tlgwindpower.com/ He's a hardhead who bucks the trend and rates his turbines at their minimum real world output rather than their theoretical maximum.)


Basically, under 10 mph wind speed with a small swept area you don't get enough juice to do anything worthwhile. Check the average wind speeds for your area, or areas where you go camping and see what the average wind speed is. Here's some data:

http://www.wrcc.dri.edu/htmlfiles/westwind.final.html



I also detect a few errors...

For one, in the Truck Camper article, Jack states:

"When the wind generators are mounted on a truck camper, they are up fourteen to fifteen feet up in the air. At that height, the wind is clean, unobstructed, and much stronger than it is near the ground."

The normal rule of thumb for small wind generators is that you have to get up to between 60' - 100' AGL to get into "clear air". Anything below 50' is going to be in the turbulence boundary layer of the ground. You can get around that if you pick a specific place that has a smooth flow - like on a ridgeline. The issue with turbulence is that the more time the gen spends "hunting", the less time it spends running at an optimum RPM.


Another error I see is on the FAQ page of the Free Spirit site:

http://www.freespiritenergy.com/faqs.html

Where it states:

"Can my battery get overcharged?
No. Voltage does not overcharge. Too many amps coming in for too long will overcharge a battery. This is simply not possible with a micro turbine such as the Windwalker 150 or 250. Think of the Windwalker generator as a “trickle charger” for your battery or battery bank."

This is incorrect - voltage most certainly DOES overcharge. (Though, I am prepared to believe that that little turbine is actually too small to put out enough juice to overcharge a normal auto type battery.)



Now, having said all of that - there IS some juice to be had. Even 1 amp per hour average over a 24 hour period is 24ah into the battery, and that sure ain't a bad thing.

 

[Jr_Explorer]

My bigest concern when reading the article was the noise the wind generator may put out. In blue water sailing power generation is a big deal (who wants to fire up the engine or a generator while at anchor in a tropical paradise lagoon). So solar and wind generators are used (trade winds and all that). But many of those generators make NOISE and this is no bueno in said tropical paradise lagoon.

However, this little wind generator probably puts out noise proportional to the energy being generated (i.e. not all that much) compared to those used on sail boats.

 

[dwh]

Concurrent with noise, is vibration. If it's making noise, it's also vibrating the structure to which it's mounted. This is one reason why it's pretty rare to see a wind turbine mounted on the roof of a house. (The main reason it's a bad idea to mount it on the roof is turbulence.)

 

[oldnslow]

dwh said "(The main reason it's a bad idea to mount it on the roof is turbulence.)"

Mounting this thing 2 feet above the camper roof (that is what it appears to be in the picture in TCM) is going to put it in very turbulent air. I believe him when he says it will not overcharge your battery, because it will not put out enough power. I bet it won't last long either. Turbulent air will kill any wind generator, sooner or later.

Articles in Home Power magazine, written by people who know wind generators, always state that the generator needs to be 30 to 50 feet above any nearby obstacle. In the desert that would usually mean 30 feet above your camper - and thats pretty hard to do with a portable setup. In a wooded area that would mean 30 feet above the trees - yikes! That is why I don't consider them useful for a camper, its just too difficult to get them up high enough to work well, and still be portable.

Note that in the TCM article he mentions that he had a 50W solar panel and it wasn't keeping his battery charged. I suspect he doesn't understand electricity very well either. He needed more solar panel, not a wind generator.

 

[windsock]

Further discussion back in this thread. http://www.expeditionportal.com/forum/threads/56997-Wind-generators

EDIT: No indication of how it shuts down once the wind is over the stated maximum 35mph (approx 15 metres/sec) and I never heard of having to 'break in' a generator.

At approx 0.67 metres diameter I don't envisage much energy capture at all.

Wind energy is calculated as 0.5*air density (kg/m^3)*swept area (m^2)*wind velocity^3 (m/s). As with most small wind designs it is caveat emptor. Homework about the technology and honest research into the likely wind resource will pay dividends in all small wind situations.

 

[Stumpalump]

My buddy has a similar sized unit on his 5th wheel toy hauler camper. He mentioned the noise since I was parked near him but I didn't hear much. Basically if it was windy enough to make it sing the noise of the wind drowned out the noise of the generator. He was worried about running out of juice because his Honda generator failed but overnight his house batteries had a full charge from just wind. They way he talked about it and from what I saw it seemed great.

 

[jameswang]

Just saw this in the latest Truck Camper Magazine newsletter: http://www.truckcampermagazine.com/news/new-product-free-spirit-energy-wind-generators. Manufacturer's website is here: http://www.freespiritenergy.com/. I have no affiliation with the product, never seen or used it, etc., but thought some of you might be interested in it. Looks like a decent alternative to solar or could be used to supplement a solar system for battery maintenance.

I think it's actually very difficult to maintain that kind of wind power system.

 

[CaliMobber]

old post but Ill just add the cost of solar these days wind is kinda silly.

Solar is much cheaper than anything wind makes and has no noise or maintenance

 

[schulz11]

old post but Ill just add the cost of solar these days wind is kinda silly.

Solar is much cheaper than anything wind makes and has no noise or maintenance

+1 -- And you just need sun to power it which most people get more of than wind. I have talked to many guys with turbines on their RVs, They all said that if they hadn't so much money on it, they would replace it with another solar panel. Everyone said this.

I picked one up from a guy who was adding solar to his rig because he didn't want to put it up and down. After he changed over to 1 335 watt panel mounted flat, he stopped needing to use his generator (with the turbine he had to run the genny every day). Since it was free, I used it for a year. I took mine down because most of the time it was no spinning due to lack of consistent wind speed, and when it was turning, it was loud and only gave me 3 amps at 12 volts. That is not even 50 watts. I gave mine away as well to the next guy who wanted to try it, he doesn't have it anymore either.

My EU2000i is quieter than the turbine and gives me 1600 watts / hour - Wind, no wind, rainy days and at night. Best $1000 if have spent for power production.

 

[calicamper]

Just saw this in the latest Truck Camper Magazine newsletter: http://www.truckcampermagazine.com/news/new-product-free-spirit-energy-wind-generators. Manufacturer's website is here: http://www.freespiritenergy.com/. I have no affiliation with the product, never seen or used it, etc., but thought some of you might be interested in it. Looks like a decent alternative to solar or could be used to supplement a solar system for battery maintenance.

Been used in the sailing world for a long time. #1 issue most people cant stand is the noise and vibration. Having one of those mounted to a camper or even set out near by would be nearly as bad as a gas generator running on the tailgate. Very costly option for a source thats really not that enjoyable to be around when running.

Solar panels are wicked efficient today and should provide plenty of juice unless your running a full on video editing suite with jumbo screens which case you'll need your own dedicated diesel powered generator unit near by anyway.