Windmill vs. solar panels

[Jerry W Campbell]

I have solar panels and a 400 watt quiet wind generator.
The wind generator only puts out only an amp or two (on the beach) with surges up to maybe 15 amps. This would be fine for a trickle charge if I only had a 100 amp battery but I have 1600 amps so for me it is useless.
Contrary to popular opinion solar panels will provide you with (if you live in the sun) all the necessary electricity to live a normal life in your bus.
I have 1580 watts to charge 1600 amps (1000 lbs.) of batteries.
We have :
Electric Fridge
two exhaust fantastic fans on most all day
coffee maker
two computers/TV 4 or 5 hours a day
100 watt stereo
two ham radios
washing machine
toaster
bread machine
all my electrical saws, grinders and tools
etc. etc.
So far almost all the work done on the bus has been with the power provided by it. Almost everything we have is 120 volts.
We have a 2000 watt inverter generator we did run a few times last winter to run our 120 amp charger while in the southwest.
Right now I'm in a spot in southern Mexico, I have sun from 11:00 am to 4:00 PM, the batteries are down to 85% at 11 and up to 100% about 2:30 or 3:00.

You cannot have a wind generator on a mobile rig that puts out enough power to do any good because they are tooo heavy to lift up and down.
Solar panels work and with the right setup are fully automatic with no moving parts.
Just my educated opinion
Jerry

[Brassman]

Jerry, I'm just wondering what size inverter do you use?

[Mex-Busnut]

Jerry:

I just sent you a personal message.

73,

XE1UFO

[Lin]

Since we did a bit of boondocking this past year, I have looked into ways to charge without running the generator strictly for that purpose.  A couple of solar panels would be maintenance-free, be permanently mounted out of the way, and would help cut down on run time.  I also considered carrying a small, very quiet generator just for charging so I could run it without feeling I was bothering the neighbors.  I would not consider the wind generator since it would require set up and storage space for a relatively undependable, small production.  Where would you put it?  If on the ground, some kid, dog, or childlike adult might cause a problem.   If you want it on the roof, installation and removal could get to be a real nuisance.  You would definitely need to add some permanent mounts that could take heavy gusts.  Either way, if a storm comes up in the middle of the night, you will have to decide if you should get out of bed to stow the equipment or allow God to take care of it.

When I had an awning, I would often close it if I were going away for a couple of hours since a surprise storm could do a lot of damage.  You would have to consider this with your turbine also.  If you leave it on the ground, you will also have to consider whether someone might steal it when you go out to see the sites.  Will you want to take it down and put it up again later? 

[artvonne]

  Short of a very large prop, your not going to generate much power with wind electric. A Jacobs with a 26 foot prop is rated at 530 KW. If you cut the prop in half, youll get about 25% so about 130 KW. Thats really not going to run much, and a 13 foot prop would be huge to be taking down and putting away in your Bus, and it really needs to be high up in the air to catch the wind... Its really something made to be permanently mounted.

  And that 530KW is max rated output, you might be lucky to see half that depending on the area and terrain.

  Anyway, to do it right there should be a governor that starts feathering the prop it out of the wind after it reaches peak rpm, and there should be a high speed brake to stop it once its fully feathered. There was one out by us that came unglued in high winds, it threw a blade many hundreds of feet. Try that at a campground.

[Sean]

... about 130 KW. Thats really not going to run much, ...

Wow, 130 kW is ten times the size of most RV generators.  I know if I turn everything in my bus on at once it's less than 10 kW.

Most RV or boat-size wind turbines are in the 4'-6' diameter range, with ratings in the neighborhood of a kilowatt.

FWIW, without air conditioning, we use about 4kWh per day of electricity.  If we wanted to go 100% solar, like Jerry, we'd need about 1,200-1,400 watts of panels (we only had room for 330 watts).  If we were someplace where the wind was pretty constant, we could probably get by with a 1 kW turbine.

I still don't care for the amount of maintenance, setup/teardown, and noise involved with wind turbines.  They are a better choice for a fixed structure, where these issues are easier to address, or a boat, where completely unshaded flat mounting surfaces are scarce and vessels are further apart in anchorages.

-Sean
http://OurOdyssey.BlogSpot.com

(Update: realized I typed radii but wrote diameter.  Fixed the numbers to match.)

[Jerry W Campbell]

Jerry, I'm just wondering what size inverter do you use?

3000 watt ProSine
2 MX60 Outback Charge Controllers
Jerry

[Ed Hackenbruch]

Keep in mind too that the taller the windmill, the more power it produces. General rule of thumb is that the wind speed at 30 ft. above the ground is twice as strong as at ground level. Also any obstructions, ( houses, trees, hills, fences, etc.), within a couple of hundred feet causes turbulence in the air flow which affects performance. If you look closely at windfarms you will notice that sometimes there are big gaps between rows or between individual towers. This is because they do site surveys to determine precisely where each tower goes to take advantage of the maximum amount of air flow for the  maximum amount of time. Lot of money involved with these things, they don't just throw them up anywhere that they feel like it.

[technomadia]

I have 1580 watts to charge 1600 amps (1000 lbs.) of batteries.

I would absolutely love to see pictures of how your solar panels are laid out...  we would love to put that much on our bus!   That's totally sweet.   We currently have a 500 aH lithium ion battery bank that we'll probably expand up to 1000 aH soon, that will give us similar capacity of your 1600 aH, but in under 300 lbs.

Our next major electrical project is solar, but not seeing how we can get more than about 700-900 watts on our 4106's curved roof. (If we could figure out how to fit mini-split A/Cs and get rid of our roof A/Cs, that would help.)


As far as living off solar...  for the first year of our full time RVing, we both thrived with a single 110 watt panel and 280 aH of battery storage.  Enough for our computers, internet and lights (we had a 16' trailer at the time). Then our 17' trailer (3 yrs of full time travel) we had 200 watts with 230 aH of AGM batteries that was a great balance for us.    Looking forward to adding solar to our bus and getting back to being more self-sufficient.

- Cherie

[pipopak]

This is the kind of windmill I have in mind:
http://www.google.com/products/catalog?client=ubuntu&channel=fs&q=windmill+electric+generators&oe=utf-8&um=1&ie=UTF-8&tbm=shop&cid=4369387138458642610&sa=X&ei=uoPZTpqLAs7HsQKK3M2WDg&ved=0CIoBEPMCMA

or this:
http://www.google.com/products/catalog?client=ubuntu&channel=fs&q=windmill+electric+generators&oe=utf-8&um=1&ie=UTF-8&tbm=shop&cid=10632941392377206689&sa=X&ei=vITZTrfhDee1sQLKgd3WDQ&ved=0CIgBEPMCMAE

Mounted on top of a post up front, easily removable when needed.

[artvonne]

Wow, 130 kW is ten times the size of most RV generators.  I know if I turn everything in my bus on at once it's less than 10 kW.

  Oops that was a typo. Actual output on the 26 foot prop model is rated at 15 KW at 26 mph wind speed. So halving the diameter would drop it to about one fourth, about 3.5 KW.

  The 26 footer is only about $70,000 with an 80 foot tower.

  Some folks we knew back in Minnesota had four of them in their family. I asked the kid about them, he said they would likely never pay for themselves in his lifetime. The maintenance alone was much more than anyone in the family paid in a years worth of electric bills.

[Iceni John]

I have 1580 watts to charge 1600 amps (1000 lbs.) of batteries.

I would absolutely love to see pictures of how your solar panels are laid out...

Cherie:

http://crowncoach.clanteam.com/

I also intend to have a useful amount of PV panels on my roof, ideally at least as much as Jerry, or even more (my Crown is 5 ft longer than his).   Jerry tilts his entire panels, which is probably the best way.   I may do that, or I may do it slightly differently  -  I'm thinking of a 12"-wide diamond-plate walkway along the center of the roof from my front roof hatch to the rear one, and hinge my panels to this walkway.   This way half the panels can be raised as high as needed, and the other half will lay down against the curved roof, and this will catch the sun almost as well as on Jerry's bus and a lot better than simply having them permanently flat.   Your 4106's roof is curved about as much as Crowns like Jerry's and mine.   Another incidental benefit to covering almost the entire roof with panels is keeping the bus cooler  -  as long as air can circulate under the panels (which helps their efficiency) there will be much less solar energy heating the roof and hence the interior.   This changes the amount of interior cooling needed, maybe to the point that simple evaporative coolers could suffice  -  their power draw may well be within the ability of a roof-full of PV and a good-size battery bank.   Just a thought.

PV is still dropping in price.   Pallets of cosmetically-blemished panels can be had for little over $1 per watt *, so 2000W or more of PV is a viable option, especially that I really don't want to run a generator except in emergencies.   After the initial expense it should be essentially free electricity generation for the next two decades or so!   Being able to keep your batteries always well-charged should also prolong their life, making five years or more from a set of cheap golf-cart batteries a reasonable expectation.   Whatever happens to diesel prices in the short-term is up in the air, but I think it's safe to assume the long-term prognosis for diesel prices will be steadily upwards, making PV more attractive as the years go by.

Jerry and his bus are my inspirations.   Jerry, you are very lucky to be able to do what you do!

John, more than slightly envious

* for example  -  http://www.sunelec.com/solar-panels-c-5.html

[Mex-Busnut]

Thanks to all for your information!

In case you guys missed it, this guy has some awesome info on full-time boondocking on 100% solar power!

http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/

[Iceni John]

Yeah!   Now that's excellent information.   That's what I want to read  -  real-world experience, not just theoretical reasons why it shouldn't work.   It gives me renewed optimism that I'm on the right track thinking I can live almost entirely off solar.   When you add in other energy savings, such as using  "fridgers" * (my description) instead of power-sapping conventional fridges, there's no reason it shouldn't work.   You just have to be imaginative and resourceful.

*  -  http://www.mtbest.net/chest_fridge.html

John

[Jeremy]

Just thought I'd update this thread with a couple of wind turbine photos taken from today's BBC news here. These are two different turbines that suffered in some strong winds we had yesterday:







Jeremy