Solar Panel Survey ?

[scanzel]

I am looking to add a solar system to my conversion and want to know what aeveryone else is using and why. Do you feel it is worth the cost to you? Is it providing for your needs and any other information you can provide.Number of panels, brand, charge controller etc.

[H3Jim]

I chose the Blue Sky solar controller.  It was SB3024i.  Blue sky invented the technology they call MPPT.

Rather than simply connecting the solar panel to the battery, the patented MPPT system in a
Solar Boost™ charge controller calculates the voltage at which the module is able to produce
maximum power. In this example the maximum power voltage of the module (VMP) is 17V. The
MPPT system then operates the modules at 17V to extract the full 75W, regardless of present
battery voltage. A high efficiency DC-to-DC power converter converts the 17V module voltage at
the controller input to battery voltage at the output.

What most people see in cool comfortable temperatures with typical battery conditions is a charge
current increase of between 10 – 25%. Cooler temperatures and highly discharged batteries can
produce increases in excess of 30%. Customers in cold climates have reported charge current
increases in excess of 40%. What this means is that current increase tends to be greatest when it
is needed most; in cooler conditions when days are short, sun is low on the horizon, and batteries
may be more highly discharged. Check the Blue Sky Energy,Inc. web site at www.blueskyenergyinc.com. It has a lot of very useful information.

Two other features of the charge controller that are very important to me are the aux charge feature that allows me to keep my start batteries fully charged with a 2 amp charger.  Makes the batteries last longer.  I only use my bus about once a month so it sits for long periods.  Its very difficult to keep all the batteries fully charged unless you have solar or have a charger plugged in all the time.  That last little bit of charge takes a long time but is critical to battery life. I found then using my generator that I never let it run those extra hours to get that last bit of charge.

The other feature I really like is the battery monitoring system.  I put in a shunt so all current either in or out of the house batteries is monitored.  If you are using your house batteries a lot, there is not really a good way to know how much charge you have left.  Its important for battery life to not discharege below 50%.  After a battery has been sitting for several hours, you can tell by its voltage, but thats not too convenient when living in the bus. This controller has a remote panel with menus so you can check various voltage, currents, state of charge, aux charging etc.  The charge coltroller also has a battery temp sensor.

Solar panels - I went  with BP, I figured I wanted to go with a name brand so if I wanted to add panels later I could be assured of finding them.  If all the panels you use are not of the same voltage, your efficientcy will suffer greatly.  I have a 24 volt system for both house and starts, so I used panels that put out a max of 34 volts althoguh the charge controller keeps that to a level that will not harm the batteries.  I used 4 150 watt panels for a total of 600 watts.  I still have some more real estate on the roof, but I also want to put a deck up top as well.  The panels are 31" by 62".  When I installed my roof airs, I put them up off center and that allowed me to put a solar panel on the fat side and still clear my awnings that are mounted on the top of the roof.  YMMV

I think its one of the best investments I've made in the bus.  Silent power all the time.  With some exceptions, I can use everything in the bus except the air conditioners and never start the generator.  That inclues all lights, microwave, stereo, tv etc.  I just installed ceramic tile in my shower and ran the lights, home theater stereo and the tile saw off the bus system (solar, batts, inverter). By the end of the day, I was still at 99% charge on the batteries.  I don't plug the bus in while parked at my house, so that was all solar panel.  My 16 cu ft refrigerator also runs 24 /7.

So I think solar is the best thing since sliced bread, and would not use any other brand of controller but the blue sky.  Panels are pretty generic, just make sure you use all the same brand and model.  I ended up spending about $4.67 for the panels alone.  You may be able to beat that.  I bought from a guy in Arizona that was near where I go play in the sand, so there was no shipping charge, and Arizona does not charge sales tax on solar stuff, so there was savings there too.

Blue sky does not sell direct, you have to use a distributor, but I did call them and talk to them and found them to be very helpful.

[Kristinsgrandpa]

  This info was posted by one of our more intelligent members some months ago. I just saved it for re-posting. It's dated Sept. 10th, 2007

It apppears to be great, but when will it be available? Soon I hope.

http://www.industryweek.com/ReadArticle.aspx?ArticleID=14932&SectionID=4

Ed

[H3Jim]

This stuff is exciting. I chose not to wait, no telling if they will really be able to bring this stuff to market when they say and at that price.  But the trend is sure in the right direction. At those prices I might do my house too.

[H3Jim]

Someone sent me a message askinghow much I paid and how difficult it was to install.  I thought my response might be interesting to others, so here's how I replied.

I'm very happy with it. I spent $700 each on the panels ($2,800) and $566 on the controller, the shunt, the remote, some 10 gauge wire and a case of Dichor to seal my intrusions in the roof.  So its kind pf pricey, but it less $ than I've spent on many other things, and its one of, if not the best $ I've spent.  Camping in a no generator spot, I can still use the microwave, toaster etc, stove top for breakfast and still be fully charged by noon.  Of course it helps I'm in San Diego, lots of sun. 

Since I am also hooked up to the bus alternator vis a big diode that charges both house and start batteries, I like it that my batteries are fully charged most of the time. that means that when I start the bus, that there is not a huge amount of power going into the batteries - that bus regulator is a single stage and does not care if it boils my batteries, it will just top them off.  Long live the batteries!

Easy to install, easier than many of the other systems I've put in.  The panels are 2" thick, rather the edges of the panels are 2", the panels themselves are about 3/16 of an inch.  I made some angle brackets out of 3" aluminum angle bought from my local metal supplier.  I was able to place the panels so all but two of the brackets could be screwed intot the metal crossbeams in the roof. I slotted the top of the angles so the panels can be removed without disturbing the brackets on the roof.  ie, the seal etc.  Two of the panels can also be tilted up because of the slots.  The other two cannot because I chose to position the bracket on the crossbeams, and they are not on the corners of the panels.  The two bracket that were over the rear fiber glass roof panel, I used those rubber compression nuts ( not sure what you'd call them)  Then go through the hole from the top, then as the machine screw/ boplt is tightened, the rubber comp;resses, sealing the hole and providing good mechanical strength too.  To be safe, I also put a bead of dichor around each bracket and in the holes of all the screws as I put them in.  The only downside to dichor is that it gets in everything, is extremly gooey, but it sure does seal well.  The installer I bought it all from has been using it for years he said and has never had a leak.  Each panel is about 1"  to 2" off the roof, there is no issue with air flow.  Thats so close not enough air could get underneath it to cause a lifting issue.

To run the wires inside, I put a waterproof conduit connector through the roof, with the roof side going into a plastic electrical box (drilled a hole in it to allow the connector to go in.  This made a waterproof box, with access to wires and to change things should it become necessary.  This allows the wires to be run inside.  I positioned the panels so the boxes are close, and they drop down inside the coach close to my main electrical panel.  The actual hook up was as easy as wiring a light switch.  Hd to find a place to mount the controoler - its pretty small, the remote panel, its also small. I have a 6 guage wire that brings 24v DC into the main panel area, so I just hooked to that (through a circuit breaker).

[David Anderson]

This is always an exciting subject.  Thanks for the details, Jim.

Steve here is a site to give some price comparisons.

http://www.wholesalesolar.com/solar-panels.html#Anchor-49425

Keep us posted.

David

[H3Jim]

here's a a pic.  You can see the brackets with the slots on the top.  The panel to the left (rear of the coach) has not been fully installed and part of the panel is just sitting on the roof.  Only the front passenger side awning has been installed in this pic.  They are now front to back on both sides.  The wire for the solar from the rear most panel runs next to the awning to the middle of the coach where the electrical box is.

[Chaz]

This stuff is exciting. I chose not to wait, no telling if they will really be able to bring this stuff to market when they say and at that price.

Thank you Jim. It's because of you, and others like you, that solar is being developed. Everything and anything is more expensive in the beginning and it's people who believe in it that make it happen for all of us to enjoy down the road. It takes money (lots of it) and interest in something to get the product rollin. I always likened it to when I was a kid a CB's were coming on strong. Or even a CD player or VCR. Expensive in the beginning then getting to where they are "throw aways".
I have great admiration for those that care and are somewhat pioneers in their own way by putting out the Big Bucks and not sitting back and waiting for it to just "happen". I know many people can't afford to do it, and that's a shame since they are the ones that could most benefit from such technology. I just wish more of the people who could afford it cared enough to fuel this sort of technology. But it's coming. I'm just hoping it gets here quicker.
  Rambled enough,
           Chaz

   (Thanx again, Jim.)

[niles500]

Has anyone come across any Holographic panels?

[John Z]

Jim, thanks a bunch for taking the time to write up a very informative reply. This is for sure something i would like to add to my coach. I especially like the sounds of that controller! But i have too many other projects i need to address first. Maybe by then, the price will have come down some too. My fantasy is to walk into an auction and find someones abandoned solar conversion project sitting there on the floor in the original boxes. And even better would be my friend Don is out of town that night and i don't have to outbid him! And no one else in the building knows the value of the stuff! Well, i can dream!