Would one of you with experience kindly post some info on solar panels please?

[Mex-Busnut]

Dear Friends,

I am respectfully requesting one or several of you with previous experience with adding solar panels to your buses be so kind as to post a primer -- a "Dummy's Guide", if you will -- for setting up basic solar charging system on a bus.

Some of my queeries:

1. What would be the minimum wattage you consider to be useful/practical?

2. How do you protect the solar panels from the elements (rain, snow, hail), plus the added rigors of a moving vehicle?

3. What would be the proper configutation to connect them to your present house batteries, which are also fed via shore power from time to time?

Once again, I am South of the border, down Mexico way. Solar panels are availble here, but expensive. For example, here is one guy offering unmounted solar cels, what he calls a "1/2 kilowatt" of power for "only" $8,997 pesos, which is about $640 U. S. at today's exchange rate.

http://articulo.mercadolibre.com.mx/MLM-73084429-celdas-solares-evergreen-de-3x6-12-kilowatt-275-celdas-_JM

Thanks in advance!

[Sean]

Have you already read through these threads:
http://www.busconversions.com/bbs/index.php?topic=14706.0
http://www.busconversions.com/bbs/index.php?topic=7604.0
http://www.busconversions.com/bbs/index.php?topic=17047.0
among many, many more in the archives?

I think you will find most of your answers in there.  Before we could answer questions like how many watts are practical (which, in turn, would determine how best to connect them to the batteries), we'd need to know what purpose you had in mind for installing them.  IOTW, what are you trying to run, and what benefit do you hope to derive from photovoltaic power?

-Sean
http://OurOdyssey.BlogSpot.com

[bobofthenorth]

As Sean said, it depends what your intentions are but in summary
- the DIY panel in your link is a bad deal
- we have 200 watts on the roof which is largely decorative
- if you are going to "live" on solar then you will adjust your lifestyle to match

I haven't looked lately but $2/watt for finished panels is likely a fair price.  The 200 watts that we have will keep the batteries up with limited TV/internet usage during the day in bright sunshine, fridge is propane but draws a low 12v current.  Other than that we need to run the genset.  I've met people who live entirely on solar in their RV but its not a lifestyle I'd willingly choose.  Unless you are willing to angle the panels for maximum solar interception you need to derate the wattage significantly from the nominal panel rating.  But read the threads Sean posted as well as Jack Mayer's site.  For some reason I can't open his front page right now so I can't link to the actual page - could be a Hughes thing or maybe he's having problems.

Jack's home page

[Bill 340]

talked to this guy at an RV show recently, was impressed with this new panel, wafer thin flexible, ad has adhesive backing, peel and stick, will fit roof or side contours,I have no interest in this product, just posting a reply to above post, check it out for your self, tell him you got his info from a bus conversion site, I was telling him I thought  busnuts may be interested in this new product,      Bill   oh yea here is his site. www.usnationalsolar.com   his name is  Tim Mattson

[sledhead]

 mex-busnut       I have 3- 60 watt panels 12 volt ,1- 20 amp charge controler with 6- 6 volt 235 amp gulf cart batteries .1- 75watt 24 volt panel for bus battery. when my wife and I dry camp for a few days and its sunny we have no problem at night watching tv, using  lights (12 volt 10 watts ,x8 up to30 x ) water pump,rv fr. on propane,water heater propane . inverter for toaster 1200 watts ac aprox 3 min., coffee maker 700 watts ac aprox 7 min. , tv 32" lcd 450 watts ac aprox 2-3 hrs .  we have a 3000 watt inverter generater but only use it if there is no sun or we use ac. most of the time the solar panels work fine.  I used 2 old awning tubes with L brackets ( all aluminum ) to mount the panels off the roof by 2 " to cool the panels . 6 years and no problems yet. almost time to change out batteries this time I will use 8 of the same as I can buy them for about $100 each . to day in ontario canada because of ontario hydro ( power ) micro fit program our solar panels have come down in price  so my system would cost about $350 for the panels ( 12 volt ) $ 80 for the controler ,10 gage wire ,fuses , misc $ 100 . old awning tubes free from my rv buddy     hope this helps                  dave

[technomadia]

A great resource is http://www.amsolar.com - they specialize in solar systems for RVs.  They have a lot of info in line with what you're asking.

Tackling a solar install over the coming months is our next major bus project (we've already done two installs on our prior RVs).  As usual, we'll be sharing what we learn.

Best wishes,
- Cherie

[Ralph7]

   I have 4 ea.  @210A./ 29.9 V. , that are mounted with stainless blind nuts 1/4x20. Bolts are all grade 8 and nylock nuts. The panels measure 39in. x 59in. and use 1 1/2 x 1 1/2 x 12in. al. angle bolted to bottom of each corner then to 4x4in. L brackets to roof , panels weigh colse 50lbs each. They could be tilted if I had confidences to do?? Panels are in paralel and Morningstar (TS-MPPT-60) controller,and has #2 welding wire  from roof to controller.
  Also  have 6 golf cart 6V. and a Trimetic TM-2025 meter.
 Now I do not know how this will work yet! Cause I have a house frig, TV, satlite self align dish, laptop, new 8cf.  12/24V. freezer  20Amp hr per day.
   Back to roof mount, the blind crush nuts are through the steel roof braces, not just the al. skin.
   

[Bill B /bus]

Four 180 watt panels at nominal 24V .  Wired series parallel to provide nominal 48 V to Outback MPPT controller.  Batteries are 6 12V Lifeline AGM's at 250AH. each. That less than the rule of thumb, one watt per amphour. We have residential refeer, Plasma TV, sat dish and receiver and microwave. Our measured usage without solar input is about 12-14 KW hr per day. We can go three days without running the genset. Afternoon evening of third day is genset time for 4-5 hours to bring batteries back to Full per the Trimetric battery monitor. By the third afternoon we are about 55-60% battery capacity.  The panels are close to flat roof mount which is great for the south, up north not so much.  Worth it?  Panels were $400 ea and $400 for controller. I think so in peace and quiet for all but 4-5 hours out of 72 hours. Two more panels would probably get us out to 4 maybe 5 days.
I second reading Jack Mayer's site.  Great info.

Bill

[Mex-Busnut]

Dear Friends,

Thanks to all for your educational contributions.

I found this website today, which was a real eye-opener for solar RV electrical stuff. Check it out.

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

Blessings.