1120 watts of Solar on the roof

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1120 watts of Solar on the roof

May 26, 2013, 11:07:43 pm

Pierce,
1120 Watts? Awesome

Details and pictures please! It must be pretty crowded up there...

Don

Quote from: Pierce & Gaylie Stewart – May 24, 2013, 11:47:49 pm

I have 1120 watts on the roof now and will be heating the system up in a week or so...

Pierce

Re: 1120 watts of Solar on the roof

Reply #1 – May 27, 2013, 12:26:23 am

Quote from: acousticart – May 26, 2013, 11:07:43 pm

Pierce,
1120 Watts? Awesome Details and pictures please! It must be pretty crowded up there...
Don

Don,

They are large 35.5 volt commercial panels the big solar farms use. 280 watts each but are big at 3 x 6.5 feet. They are made by Lingli, the world's largest manufacturer of solar panels. The guy has plenty and at $0.61/watt, that's pretty cheap. He just got back from installing 80,000 panels in the Lancaster area and his company has gone over 500,000 panels installed. Panels are the ones at the bottom at: YGE 72 Cell Series | Yingli Solar Panels are new and have never been installed.

The mppt controller is the big expense even at a discount price of $610 + $10 shipping from Arizona. It does a DC to DC conversion and will take any input up to 150 volts and convert to 12 volts (or any other voltage the batteries are). Does the input and output automatically no matter what you throw at it. Rated at 96 amps so the 93 amps from the panels is maxing it out. Panels can be connected in series or parallel or a combination. A cold morning might bring the voltage above 150 if all four were wired in series. See MidNite Classic 150 controller at: MidNite Solar Classic 150 MPPT Charge Controller Controller has a nice MAC or PC app to read out all the numbers and a LED on the unit too.

Would like to be able to tilt the panels for winter but at 6.5 feet, I think they are too long and will need a center support making it harder to set up a neat pivot for them plus I want to go to Bend, OR next weekend so may put off the tilting part for a while. Was thinking of a offset butt hinge but need a little larger than I can find online to match up with mounts at each end. Crank up antenna has to be turned 90 degrees on the roof to clear the last panel. Mounting the controller in the top compartment where the canned goods normally go. EZ down to the floor from the sink roof vent, just one hole needed above the wet compartment on our U300/36.

Will post photos as I install them.

This post should go into a new topic.

Pierce

Re: 1120 watts of Solar on the roof

Reply #2 – June 24, 2013, 06:25:49 am

Pierce,

Have you installed the solar panels yet? I would love to see pictures and know how well it is working.

Thanks Phil

Re: 1120 watts of Solar on the roof

Reply #3 – June 24, 2013, 09:58:25 am

This looks really interesting. I'm in the San Francisco Bay Area. Does Yingli ship from there?

I have an Aug 15 appointment with AM Solar but I'd like to get my solar installed before my new fridge.

best, paul

Re: 1120 watts of Solar on the roof

Reply #4 – June 24, 2013, 01:38:21 pm

Phil,

No, the panels are up on the U300 roof and the mounting brackets, wiring, 1 x 2 aluminum tubing, etc are here as well as the MidNite 150 contoller is installed. Installing disconnect breakers for the panel side and also the battery side. Made up 4/0 cable so I can bring the battery to the controller with almost no loss from the panel to the Foretravel panel directly below. I have been trying to finish a bathroom remodel, and clearing brush for fire season so only have a little time right now.

Paul,

This company uses Yingli panels for their solar farms. I bought mine directly from him and made two trips with two panels strapped onto the top of our RAV4. He sold twenty to a fellow from Northern California while I was there. I think he may be in Romania now for a month with his parents. You would need a trailer or PU to transport them from his W. Sac location as they are way too big for a SUV without putting them on the roof. Keep calling if interested.

Another company had (4) 220 watt panels in factory packaging for $0.42/watt when I bought ours but instantly sold out. Just noticed this ad with 280 watt panels for $0.69/watt at 280 watt Perlight Solar Panels for sale 69 cents a watt!!

Will have it up and running in August as we will be visiting family in England, France and Spain in July. Going to do a review of TomTom vs. Sygic vs. Navigon (Garmin) on an iPad while there and will post results when we get back.

Pierce

Re: 1120 watts of Solar on the roof

Reply #5 – June 24, 2013, 07:32:24 pm

Thanks for the info Paul. I keep getting ready to start to put things together and life gets in the way. Each time I go back to address it produts seem to change. Feels like I am after a moving target. Keep us posted as I look forward to seeing the end results.

Regards Phil

Re: 1120 watts of Solar on the roof

Reply #6 – June 24, 2013, 11:33:29 pm

Pierce,

I assume the panels do not come with the alum tubing. Correct?

best, paul

Re: 1120 watts of Solar on the roof

Reply #7 – June 25, 2013, 01:12:58 am

Paul,

No, the panels have about a 2" aluminum frame all the way around. Using aluminum angle brackets, I could just bolted it to the roof but I wanted to raise it a couple of inches to get some air flowing under and be able to bolt to each Foretravel frame member on the roof and then using commercial panel mounts, bolt the panel to the aluminum tubing. A lot of people epoxy but I didn't like the possibility of a panel flying off.

The cooler the panel runs, the more power it puts out. I selected 1" x 2" rectangular aluminum tubing with 1/16" wall thickness. The least expensive source turned out to be in Sacramento, right among all the RV dealers. It comes in 24 foot lengths @ $48 each. I needed eight 6 foot sections so had him just cut 6 foot lengths. The tubing is 3 inches short at each end but makes no difference at all. The Harbor Freight stud finder easily found all the metal members using the metal setting. The panels are 36 volts and I am doing a series/parallel installation so will have approx. 72 volts at the controller. The controller automatically turns any DC voltage up to 150 volts into 12V+ and will handle 96 amps. I could have gone all series and been under 150 volts normally but on a very cold morning, the panels could easily exceed 150 volts. The four panels are all that the MidNite classic 150 can handle. Any more and it would require another controller. The problem with any panel much over 100 watts is that they are not 12V but 24V or 36V. This requires a mppt controller that is VERY expensive. Norther Arizona Wind and Sun Solar electric power components and solar panels beat everyone else by over $100 but was still $610 delivered. It has a USB port and MidNite supplies a Mac or PC application to monitor everything.

In short, at $170/each, the four panels are going to be about 40 to 45 percent of the cost of the system. I already had 6 excellent solar batteries so did not have to spend any more, otherwise they would have added $2000 additional.

Photos are worth a million words so will have some after I get back.

Pierce

Re: 1120 watts of Solar on the roof

Reply #8 – June 25, 2013, 06:12:55 am

Looks good Pierce from your comments. We manage fine with our wattage (with residential fridge too) so you are going to be well covered!!
We just did a couple of trips into Spain and came across a solar farm that at a guess was around 500 hectacres (or more) and a lot of homes are using solar for both electricity and warm water!
Weather should be great for you in Barc' and has been between 30 c to 44 c on our trip.
It does get tough to sleep sometimes though
John

Re: 1120 watts of Solar on the roof

Reply #9 – June 25, 2013, 09:44:04 am

Thank you very much, Pierce.

Enjoy Europe!

best, paul

Quote

Paul,

No, the panels have about a 2" aluminum frame all the way around. Using aluminum angle brackets, I could just bolted it to the roof but I wanted to raise it a couple of inches to get some air flowing under and be able to bolt to each Foretravel frame member on the roof and then using commercial panel mounts, bolt the panel to the aluminum tubing. A lot of people epoxy but I didn't like the possibility of a panel flying off.

Re: 1120 watts of Solar on the roof

Reply #10 – June 28, 2013, 12:07:17 am

Pierce,

AM Solar questioned using the MidNite Solar Classic 150 because of concern about fan noises.

Are you aware of excessive noises?

best, paul

Re: 1120 watts of Solar on the roof

Reply #11 – June 28, 2013, 01:20:36 am

Paul,

Since I don't have it operating yet, I can't comment from personal experience. It does have two small fans but I can't see how they could make much noise. If operating in a dusty environment, it can be totally sealed but will loose a little output. It does not even have to be mounted in a well ventilated location. Only a little over a foot long, about 5 inches wide and 4 inches thick. The fans are tiny. It's very heavy with a very thick aluminum case so even if the small fans made noise, I can't imagine being able to hear them.

With 1120 watts, there is no other mppt controller capable of handling my four panels. I would have to buy two of another brand. If concerned, contact Northern Arizona Wind & Sun at: Solar electric power components and solar panels They are extremely helpful. Lots of good reviews for their company online.

Here is the user manual: http://www.midnitesolar.com/pdfs/classicManual.pdf Not many questions it doesn't answer plus there are several YouTube videos on it.

Pierce

Re: 1120 watts of Solar on the roof

Reply #12 – June 28, 2013, 11:13:36 am

Amazon has a line of MPPT charge controllers that seem too good to be true; at least pricewise. I wonder if anyone has tried one of them. One review on a 20-amp version says that it's not MPPT but that review is flawed in a most basic manner (the reviewer clearly does not understand electricity).

These controllers are available in several current ranges up to 30A and, if they work as specified, seem to be a good choice for RVs. The 30A unit at 24vdc should work for solar arrays up to about 700-watts. This is the 20-amp version and I am posting this because it include the erroneous "review": MPPT Tracer 2215RN EP Solar Charge Controller Regulators 20A - Amazon.com

These are not as convenient as the ones Pierce is using because they only go up to 36vdc (the nominal no-load voltage of a typical 24vdc panel) of input voltage. But their specs look quite good and the prices are very good compared with the other controllers on the market.

Clearly from China. But since when has that stopped us?

Craig

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Re: 1120 watts of Solar on the roof

Reply #13 – June 28, 2013, 01:03:02 pm

Craig,

Right about China. I just did a remodel on our bathroom with new window, shower, tile, granite, etc. Everything was made in China. Not one thing with the possibility of the drywall made here.

OK, off my soapbox. I don't see anywhere near 700 watts of solar panels into a 12V RV battery bank utilizing the Chinese mppt controller listed above. Here is an excellent calculator provided by MidNite: MidNite Solar - Classic Sizing Tool. You just read the label on the back of any solar panel and insert the values into the sizing calculator.

For many of us dry camping the panels on the roof and the controller are exactly the same as living at home on the grid. If something goes wrong, I don't want to have to email China and negotiate a repair or return while depending on the generator. MidNite as well as several others are made here in the states and can give advise as well as get a replacement or parts overnighted to your location. Northern Arizona Sun & Wind also has excellent support on what they sell.

MidNite's 150 is just able to handle 1120 watts with not much capacity left over. That's 96 amps and my panels come pretty close to that.

OK, using the info found on the photo below, everyone can plug these values into the sizing calculator at the link above and see what they get. Good to keep handy in case you are in the market for solar panels/controllers. EZ to translate to another brand of controller. Nominal Battery Voltage (Volts) towards the bottom of the sizing tool means your Foretravel battery bank voltage (12V).

I found the sizing calculator and then called N. Arizona S & W and they ran the numbers with the same result.

Pierce

Re: 1120 watts of Solar on the roof

Reply #14 – June 28, 2013, 06:16:01 pm

Quote from: Pierce & Gaylie Stewart – June 28, 2013, 01:03:02 pm

I don't see anywhere near 700 watts of solar panels into a 12V RV battery bank utilizing the Chinese mppt controller listed above.

That MPPT controller listed above is only rated at 20A. The website with the most information indicates that it's good to 480W depending upon solar panels used. They have a data sheet pdf.

Amazon lists a 10A MPPT controller by the same mfgr. as well as a 30A controller (for $169 at sainsoft) but I haven't found a data sheet for it yet. If the 20A will do 480-watts then the 30A should do about 635-watts. I'd like to find someone who has put these into service and has some real-world data. And yes, I know that the calculator says something different.

I have no problems with buying these if they work as spec'ed even if they come from China. There are importers with support here in the US, after all. We can survive for a couple weeks on a generator or even move to an RV park while any issues settle out.

Here is a web site with information on the 20-amp unit: EV-Power | MPPT Solar Regulator 12/24 V, Tracer 20A, Input 100V (TR-2210RN) . It appears to be well thought out. And certainly inexpensive!!! (That $99 price is in Euros, by the way.)

You can also gang these... use panels with their own MPPT controller for the starting battery and then use that system to help charge the house batteries. Or even run two (or more) controllers off the same solar panels to the same battery bank.

Craig

Re: 1120 watts of Solar on the roof

Reply #15 – July 01, 2013, 12:06:29 pm

Thanks, Pierce,

I gather I can access the controller via the Internet.

Is that only via a patch cable? Or can it also do it via wi-fi?

Do I have to be able to access/touch the controller for any reason?

Once I get my new 26in wide refer in I'll have a 10in wide vertical storage area. I plan to put the refer compressor on the top shelf.

Then the controller on the next shelf down. Is this an acceptable location?

best, paul

Quote

Paul,

Since I don't have it operating yet, I can't comment from personal experience. It does have two small fans but I can't see how they could make much noise. If operating in a dusty environment, it can be totally sealed but will loose a little output. It does not even have to be mounted in a well ventilated location. Only a little over a foot long, about 5 inches wide and 4 inches thick. The fans are tiny. It's very heavy with a very thick aluminum case so even if the small fans made noise, I can't imagine being able to hear them.

With 1120 watts, there is no other mppt controller capable of handling my four panels. I would have to buy two of another brand. If concerned, contact Northern Arizona Wind & Sun at: Solar electric power components and solar panels They are extremely helpful. Lots of good reviews for their company online.

Here is the user manual: < http://www.midnitesolar.com/pdfs/classicManual.pdf
Quote

Not many questions it doesn't answer plus there are several YouTube videos on it.

Re: 1120 watts of Solar on the roof

Reply #16 – July 01, 2013, 01:35:56 pm

We have been using a Morningstar Tristar MPPT-60 solar controller for a couple of years and find it works very well. Limit is 60-amps and we have it mounted on a compartment wall not far from our house battery bank. We have a remote display panel on our kitchen battery panel and manage the controller from our computers over an Ethernet cable plugged into the MPPT-60. We have changed charger parameters and monitor history. We also have a AC breaker panel mounted next to MPPT-60 with a circuit breaker on input from panels and another breaker on output to batteries. When plugged into campgrounds we have decided to turn breakers off to avoid charge voltage conflicts. We can also turn charger off from remote panel.

Re: 1120 watts of Solar on the roof

Reply #17 – July 01, 2013, 09:06:46 pm

Paul,

Got to catch a plane so back to you in a month. Suggest downloading the Classic 150 installation manual. Will have photos when I get back. Manual has all the ethernet usb, wifi info as well as mounting instructions/requirements. Training video at MidNite Solar Classic Charge Controller Training

AM Solar does not sell a controller over 60 amps. May be the reason for the "concern" over fan noise.

Pierce

Re: 1120 watts of Solar on the roof

Reply #18 – July 01, 2013, 10:19:54 pm

If solar controller has potential fan noise, why not use a remote meter and locate controller in compartment?

Re: 1120 watts of Solar on the roof

Reply #19 – July 02, 2013, 06:22:14 am

Pierce, Great info I will watch that video a couple times. Thanks

Re: 1120 watts of Solar on the roof

Reply #20 – July 02, 2013, 07:25:36 am

Thanks!

Don't think anyone could hear the super tiny 1" fans but the display is removable and could be located anywhere. I put ours in the top "canned goods" compartment. Door closes normally. MPPT controllers are very efficient so don't put off much heat. A lot of brands don't have fans at all. The 150 will run sealed but is derated to 80 amps if I remember correctly.

Pierce

Re: 1120 watts of Solar on the roof

Reply #21 – July 02, 2013, 04:01:43 pm

wa_desert_rat listed a 20A solar controller that would handle 480 watts, but, I reviewed the literature on the URL and it is rated at 260 watts at 12 volts. Most manufacturers rate their solar controller's max amps on amps going into the batteries (not amps input from the panels) and max voltage on VOC. A 480 watt panel at max output and with heavily discharged batteries could be pushing 40 amps at 12 volts into the batteries, which would smoke this controller. From a practical point of view however, given that nobody gets maximum wattage into batteries, this 20 amp controller could be used to control a 380 watt panel.

It is very easy to become confused about Watts, volts, and amps. The most useful measurements for selecting solar panels and controllers are VOC (Volts Open Circuit), SCA (Short Circuit Amps), MPPT Voltage/Amps, and battery charge Amps.

The 280 watt panels mentioned previously have the following numbers: 45.0 VOC, 8.35 SCA, MPPT 7.89 Amps @ 35.5 volts (the MPPT voltage at which the panels can produce the rated wattage). At voltages higher or lower than 35.5, these panels will produce less than 280 watts.

I have a Blue Sky 50 amp controller which is rated to handle 50 amps into the batteries. Fifty amps at 12 volts equates to 600 watts, but at 14.2 volts, equates to 710 watts. I have 880 watts on the roof and once saw 47 amps going into the batteries, but never the 73 amps which this system could, in perfect conditions, provide. My panels are permanently mounted on the roof, tilted to the curb side to enhance air flow and to provide most watts when my Foretravel is pointed east. Getting maximum watts from panels will occur only if you point your panels exactly at the sun all day long (ie move every 10 minutes). Maximum amps will happen only when your batteries are heavily discharged at maximum watts (Note watts and amps in the last two sentences).

I could get more watts by tilting my panels upward when parked, but, I do not like walking on the roof. Most folks do this, but I chose to buy more panels instead.

Barry mentioned that he turns off solar charging when plugged in. I do not do this, I use the solar for charging batteries most of the time, and sometimes (rainy day) when plugged in will turn on the converter to help with charging. I have a switch in the kitchen to set the converter voltage to either 13.4 volts or 14.0 volts. I monitor the state of charge of each battery with amphour meters.

Re: 1120 watts of Solar on the roof

Reply #22 – July 04, 2013, 04:46:19 pm

Quote from: P. Wyatt Sabourin – July 02, 2013, 04:01:43 pm

wa_desert_rat listed a 20A solar controller that would handle 480 watts, but, I reviewed the literature on the URL and it is rated at 260 watts at 12 volts.

Well... no, I gave the 20A unit for illustration but the 30A was supposedly able to handle 480W. However I think they are being somewhat misleading. It would take a 40-A (current to the battery load) to safely handle 480W. They do have a version that is 40-A but it's not easy to find. Although it does have a remote ammeter which would be handy. Price is supposedly around $200.

The only really confusing thing about MPPT is that the current IN to the controller may be completely different than the current going OUT to the battery load. Since you can use 36-v panels (which are 24vdc) then the current into the controller would be half that going into the batteries at the same power rating. You have to be sure what side of the controller you're talking about.

There are several major advantages to using MPPT controllers and one of the biggies is that by connecting them in series you can get very high voltages with a correspondingly lower current for the same power. This translates into smaller wires going down to the MPPT controller from the solar panels on the roof. A distinct advantage in our situation.

I think Pierce might be on the right track with that Midnight Solar 150 due to its ability to take much higher voltages than most MPPT controllers. But if you don't have a lot of solar panels on the roof you can use those tracer MPPT controllers for a lot less money than many others are selling controllers for.

I'm still on the fence about how I'm going to do my solar installation. It was supposed to be done by now but the engine wiring and shifter cable issues took precedence. I'm leaning towards installing 150-W of solar on the fishing trailer (21' Streamline Princess) and using one of those Tracer MPPT controllers for that. If I do that I might just go for the MS 150 on the coach as that would allow upgrades to the point where every usable inch on the roof is covered by solar panels.

Craig

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