Wind Turbine vs. Solar Panels

[PNGento]

We are getting ready to go full-time RVing. I am wondering about getting some type of renewable power generating equipment. Wind turbines are more efficient than solar, but there seem to be more solar choices. Has anyone gone the wind turbine route? How about those who have gone solar? If you have gone one route vs the other, can you share your experiences, pros/cons, sources, etc. I would love to hear what others have discovered. I am surprised this topic hasn't been beaten to death, but a search isn't showing much information on either solar or wind turbines.

 

[okiejim]

I have tried both. I'm solar on my TH. Granted on overcast days I could generate power when the solar was not able to generate. That is the beauty of having both systems available. The problem is the wind turbine needs to be up about 40' to catch a strong enough and sustained amount of wind to produce good power. Also the wattage advertised is not true. I have a 500 watt turbine that would average about 6-10 amps of power with a 10-20 mph wind, and only as long as the wind was steady. Depending on the wind speed. Erecting it and take down took way long for such little power. Save your money for solar you will be much better off for mobility. Now if you are going to do this at a fixed location it is great for that. Just my 2 cents. I still have the turbine and want to install it at a long time stay location. Just have not figured out where it will be yet.

 

[arlan in arizona]

I have also tried both. Solar is the answer. If you are set up for months in one spot the wind generator might be OK. My thoughts are, I hope to have more sun than wind. Solar is installed, ready to go and not an item in a box or case with poles that you have to deal with everytime you move. Solar is the best.

 

[DonZinger]

I've not tried wind but absolutely sear by solar - we dry camp at several NASCAR events each year and I run everything in the rig off the solar all day with juice to spare to fire the generator up for morning coffee. Plus I charge while running down the road (making ice in the ice maker for arrival cocktails) - I'd be afraid to see what 70+mph winds would do to a wind generator if I tried that! LOL

 

[PNGento]

I've not tried wind but absolutely sear by solar - we dry camp at several NASCAR events each year and I run everything in the rig off the solar all day with juice to spare to fire the generator up for morning coffee. Plus I charge while running down the road (making ice in the ice maker for arrival cocktails) - I'd be afraid to see what 70+mph winds would do to a wind generator if I tried that! LOL

I think this raises another question, but first, let me get clarification from you: To do all that you say you do, I assume you have installed (or already have) an inverter to convert your DC to AC...is that correct? I also assume that your rig 3950 did not come with one...I know my 3905 didn't.

So, it appears you have 370 watts of solar power...are you able to watch TV, use your computers, run needed lights with that amount of solar? In short, do most everything except maybe AC and/or microwave...or can you even do that?

Finally, how are most using solar? Permanent install atop the roof? On mobile stands? If on the roof, is it in a static position (don't have to move it/aim it)...or do you have to somehow aim it. We go full-time in under a month, but don't begin travel until first part of May. It is sounding as if solar is the way to go, so if anyone can provide links to units they have purchased and are using...on then more on the installation, is DIY possible on install?...anything you can provide is welcomed.

 

[DonZinger]

I have a 2000 watt Xantrax inverter as well as a smaller 750w. I run TV, DirecTV, stereo, icemaker, plus all the fans, refer and everything inside. I have a 4-6V golfcart batteries. I did self-install - was easy. I got my panels from Home Depot website - Grape Solar units - used military discount. I installed mine directly to the roof (2nd unit I have done this on). I chose not to bother with brackets that were adjustable as I never felt the need to on last RV so didn't on this one. I have nevr had an issue with a lack of power, plus I didn't feel like climbing up there to adjust them. Pull it set up and relax. Hope this helps...

There are specific connectors I used that are made for solar panel connections that are also water proof the name escpes me right now but I can look itup if you need - they are crimp on with sealing o-rings. I also used the "Y's" from the same manufacture to run mine all parallel.

 

[PNGento]

Does the HomeDepot kit include brackets allowing you to attach it to your roof? Don't see that addressed by the information on HD's site. But, it appears that everything else you mentioned would be included. I would need to add two more 6-volt batteries (only have 2 right now), but this sounds very doable. I am probably weaker in electrical issues than anything else, but do understand a reasonable amount of electrical...would the kit be doable for your above average DIYer (but somewhat weak on electrical)? And yeah, the military discount will help (retired Navy here)...what branch Don?

 

[DonZinger]

I went with brackets from Renogy simply because I had used them before - there a literally thousands of options for brackets:

Solar Panel Z Bracket Mounting Mount Flat Roof Wall Aluminum Set 4 Pcs Kit | eBay

The connectors were Mc4:

Amazon.com : 5 Pairs of MC4 Male/ Female Solar Panel Cable Connectors : Solar Power Meter : Patio, Lawn & Garden

I used wire simliar to this in lengths I needed:

http://www.amazon.com/Solar-Panel-C...d=1423763894&sr=1-49&keywords=solar+panel+mc4

This tool lets you assemble and disconnect the Mc4 connectors:

http://www.amazon.com/Vktech-Solar-...d=1423763894&sr=1-55&keywords=solar+panel+mc4

I used this connect them up parallel:

http://www.amazon.com/Signstek-Bran...4026&sr=1-3&keywords=solar+panel+mc4+parallel

I ran the two wires down the vent pipe into the basement area and fed it out a hole I cut in the vent pipe - I don't have a pic of this right now but will get one in the future when I start up the "honey-do list" in preparation for the upcoming season.

 

[DonZinger]

Does the HomeDepot kit include brackets allowing you to attach it to your roof? Don't see that addressed by the information on HD's site. But, it appears that everything else you mentioned would be included. I would need to add two more 6-volt batteries (only have 2 right now), but this sounds very doable. I am probably weaker in electrical issues than anything else, but do understand a reasonable amount of electrical...would the kit be doable for your above average DIYer (but somewhat weak on electrical)? And yeah, the military discount will help (retired Navy here)...what branch Don?

This actually very easy to do - just get over your fear of running screws into your roof and the rest is easy! I was 24-years Army. I can give further tips when you get ready to pull the trigger on this - such as pointing male and female Mc4 connectors in oppostite directions to distinguish + and (-) when you feed them down the vent pipe - and keep the panels covered when working on the wiring - they will give you a pretty good poke ona sunny day!

 

[PNGento]

The picture shows a solar charge controller...this doesn't appear to be part of the HD kit...or am I missing something? Did you buy this separate? If what I have learned is correct, a charge controller can make better use of the available power being generated, so sounds like something one would want.

 

[DonZinger]

Too make a long story short and simple - you will have to have a charge controller of some sort - I have a Sunforce 30A - Coleman actually sells the exact same unit with their name on it. I monitors battery level and automatically does bulk, maintain and trickle charging. There are better or more sophisticated units out there, but this is what I put in my first rig and I liked it so I stuck with it. I didn't get a kit from HD. I had two Kyocera 85-watt panels I took off my last RV when I traded in and bought 2 of the 100-watt panels from HD. I didn't get a kit - just bought the components to make my own the way I wanted it.

Here is a pretty good site for informational use:

AM Solar's Educational Pages for RV Solar Systems

 

[DonZinger]

This is the the charge controller I am running:
SunForce Products Inc. - Charge Controllers - 30 amp Digital Charge Controller

 

[ewarnerusa]

I'm very happy with our solar investment. I went through Solar Boulevard and have two 140 watt 12V panels and use a Morningstar Tristar 45 PWM controller. I built with expansion in mind, but have not yet been compelled to expand. I run a 300 watt or a 1500 watt pure sine wave inverter, usually just the 300 watt one for efficiency because we are only running a TV and some fans off of AC power. The 1500 watt inverter is not quite powerful enough to run the microwave, but that isn't something we miss. I use the stove to heat water for French press coffee. All lighting converted to LEDs. If I'm setup in a suitable spot for a nice full-day harvest, we don't ever run out of battery power.

I went with flat fixed mounting, I think a big benefit of solar is that it can be installed and then left untouched to do its thing. I didn't want to be climbing on the roof adjusting panels. I never considered wind for this same reason. Wind doesn't seem like it lends itself well to a portable operation.

While solar can directly run things when the amp load is less than or equal to what the panels can immediately provide, your batteries are really your main power source when off-grid. They are the power reservoir and the solar panels are the incoming river. The solar is used to recharge the batteries, just like the river is filling the reservoir.

If you want countless solar threads to read through, head over to rv.net. "solar" search results

Some other reading is the Handy Bob Solar Blog. It is very wordy to wade through, but there is some valuable content and real world experience.

First step before you go buying stuff would be an energy audit to determine your power needs. Then build a battery/solar charging system around that.

 

[Rupert]

The UPS man just dropped this off at my house... http://www.amazon.com/Renogy-100W-M...ie=UTF8&qid=1423788471&sr=8-1&keywords=Renogy

The install instructions say to use well nuts to secure the bracket to the roof. How did you all attach to your roof? i am worried the roof material will be too thin to get a good grip on the screws. Ewarnusa, looks like we both have an Aspen Trail, can you make a recommendation?

Thanks for the help

 

[ewarnerusa]

I used Z brackets and screws. 6 per panel. The roof is thin plywood over trusses. Try to hit the trusses.

 

[DonZinger]

I did the same Z brackets and screws - have had zero issues to date and never had any issues on my last RV with same mounting.

 

[ewarnerusa]

That kit looks pretty good. I would say it would be all you need for one battery. You don't mention how many batteries you have, but 100 watts per battery is a reasonable rule of thumb. It doesn't indicate if it comes with wiring for controller to battery. You want to minimize voltage drop over this path, and maybe even plan for expansion. Try to locate the controller as close to the batteries as possible and use fat gauge wiring. Maybe 8 gauge minimum? That controller could accommodate 4 of those panels, so plan around that. in that case, 4 gauge wiring if the controller terminals can accept it. Also consider quality battery terminals for that fat of wiring. And in line fuse.

 

[Rupert]

Thanks for the info !!! The kit came with the panel, Z brackets,2 20' lengths of 12 gauge wire with MC4 connectors and the 30 amp charge controller. I'm ditching the wiring for 8 gauge as it looks like I am going to have to have a really long run as I don't want to drill through the roof. I will be running the thickest I can fit in the terminals from the battery to the controller, haven't messed with it yet to figure out that size. I currently have 2 group 24s on the tongue. The trailer came with 1 and I got another deep cycle for 25.00 off craigslist. They are both the same age and in good condition. planning to go with 2 6volts when these die. I'm leaving the solar system open for expansion, I think I can fit 3 of these panels on our tiny little roof. I have not been fortunate enough to find good dry camping as we live near DC, but I like having the solar there, just in case.

 

[ewarnerusa]

Sounds fun! While voltage drop certainly occurs between the panel and controller, it isn't as much of a concern because the PWM controller will typically be cropping off voltage anyway so it delivers the appropriate voltage to the batteries. If you went with MPPT, then you would be motivated to minimize this voltage drop because MPPT can take this excess voltage and turn it into current. I initially was looking into using fat wire from panels to controller, too, but I couldn't find any with the MC4 connectors that were any larger than I think 12 gauge.

If you don't want to cut a hole in the roof, consider routing down through the refrigerator vent. I was reluctant to drill holes, too, but ultimately I did. I figured there are many other holes in the roof for skylights, A/C, etc., so as long as I used Dicor sealant it shouldn't be any worse than the other holes.

 

[PNGento]

What about solar AND shore power...conflicts?

I think I understand the concept of solar and how the generated electricity gets from the solar panels to the batteries via the controller...but where I am getting lost is when you then factor in an inverter. The inverter converts the battery power from 12 volts DC to 120 volts AC. So, how do you get access to the inverter supplied power? Do you hook it into the existing power system so that all current outlets become available to the solar provided power (supplied by the batteries)...or do you have to wire a totally separate power system dedicated to the inverter? If so, then if I wanted to use the microwave, I would have to put in a separate circuit and then unplug the microwave from the shore circuit and replug into the solar/inverter circuit??

Surely there is a way to make it so that the system could be plumbed into the existing shore circuitry...either automatically via some type of electrical switching...or at least by throwing a switch to dictate if the power is being supplied via shore versus battery/inverter. I'd think nothing good would come if you were running on inverter provided power and then also plugged into shore power...or would it even be an issue? I know I want to get so I can be self-sufficient, but still be able to use the occasional microwave or my wife use her hair dryer...but not to the point of being able to use the AC. But having trouble getting all the pieces to fall into place.