Jump to content

Solar Novice


Mariner

Recommended Posts

  • Replies 69
  • Created
  • Last Reply

Depends on the panels....... Not my number one science, but I seem to recall max voltages in the 30's on many of the popular units. That's what goes into your regulator which turns it into 13.X VDC. Based on 480 Watts in full sunlight, properly oriented and, say, a 90% efficiency you should expect somewhere around 35 amps.

 

Watts = Volts X Amps

Previously a 2017 Forest River, Berkshire 38A, "The Dragonship". https://dragonship.blog/

Link to comment
Share on other sites

A lot of factors come in to play outside of just calculating panel specs.. location, orientation, etc. A quick search would probably pull up a solar calculator that would give you a general idea of what to expect from your panels in any given location.

Link to comment
Share on other sites

I've read Jacks solar section a few times and it's still all Greek to me. I'm showing output charge current of 9.2, and solar panel current 3.8. What does all that mean. Do I need a solar tune-up? Or am I ok? I have to go out for an hour or so, but will definitely be checking back when I return. Anyone know where Jack is? I heard he was in Tampa.

Fulltiming since 2010

2000 Dutch Star

2009 Saturn Vue

Myrtle Beach, SC

Link to comment
Share on other sites

Where are you getting your reading from and what solar controller are you using? Depending... you may only be seeing what is currently being supplied by your solar controller based on load demand... not what your system is fully capable of. More information is required.

Link to comment
Share on other sites

Where are you getting your reading from and what solar controller are you using? Depending... you may only be seeing what is currently being supplied by your solar controller based on load demand... not what your system is fully capable of. More information is required.

Now that makes sense. Maybe the fog is lifting. Are you saying I should unhook from shore power to see what it will actually put out when it senses a need for power?

Fulltiming since 2010

2000 Dutch Star

2009 Saturn Vue

Myrtle Beach, SC

Link to comment
Share on other sites

Are you saying I should unhook from shore power to see what it will actually put out when it senses a need for power?

 

I don't have enough info to say yes or no without knowing which controller you have and where you're getting your reading from, but it certainly wouldn't hurt anything it give it a try. If your batteries are fully charged and your 12v loads are light you may not see a significant increase in output, but you COULD disconnect then turn on all your lights or the furnace to test the theory that that is in fact the reading you are seeing (controller output).

Link to comment
Share on other sites

Depends on the panels....... Not my number one science, but I seem to recall max voltages in the 30's on many of the popular units. That's what goes into your regulator which turns it into 13.X VDC. Based on 480 Watts in full sunlight, properly oriented and, say, a 90% efficiency you should expect somewhere around 35 amps.

 

Watts = Volts X Amps

Most solar panels have a 11-15% efficiency

 

 

us.navy.sere.patch.16.jpg

Link to comment
Share on other sites

I have something called RV Power Products SB 50 Remote Display. That's what I'm looking at for power output.

 

Good deal. That's a Blue Sky so you can just change your monitor display to show panel/array current, battery voltage, or output. No need to unplug or apply 12v loads. Refer to your manual if you are unsure how to change the display setting.

 

Most solar panels have a 11-15% efficiency

 

As cheap as panels have become, it's really not that difficult or expensive to find panels more in the 17-21% efficiency range with power ratings @ 90% or better @ 10yrs.

Link to comment
Share on other sites

google what % efficiency is a solar panel

 

 

OK, we're talking two different things here.

 

I was referring to to what you can reasonably expect to get out of the rated power of a panel. So, if you have a 100W panel, and it's nice and clean, perfectly oriented, and the sun is blasting it with minimal atmospheric disturbance you should be getting 90% or better of it's rated power. There is some loss in wiring, regulating and of course setting it up perfectly and tracking is a tall order.

 

What you are referring to is the amount of the total sun energy hitting it's surface that a panel can convert. That is indeed in the 10-15% range. Yes wouldn't it be neat if a 2x3 foot panel gave us 900 watts.....

Previously a 2017 Forest River, Berkshire 38A, "The Dragonship". https://dragonship.blog/

Link to comment
Share on other sites

I've read Jacks solar section a few times and it's still all Greek to me. I'm showing output charge current of 9.2, and solar panel current 3.8. What does all that mean. Do I need a solar tune-up? Or am I ok? I have to go out for an hour or so, but will definitely be checking back when I return. Anyone know where Jack is? I heard he was in Tampa.

I'm in Mayo FL where John Palmers solar shop is. Headed to Tampa tomorrow to stage for the show. Stop by the New Horizons display if yo are at the show.

Jack & Danielle Mayer #60376 Lifetime Member
Living on the road since 2000

PLEASE no PM's. Email me. jackdanmayer AT gmail
2016 DRV Houston 44' 5er (we still have it)
2022 New Horizons 43' 5er
2016 Itasca 27N 28' motorhome 
2019 Volvo 860, D13 455/1850, 236" wb, I-Shift, battery-based APU
No truck at the moment - we use one of our demo units
2016 smart Passion, piggyback on the truck
-------------------------------------------------------------------------
See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar power
www.jackdanmayer.com
Principal in RVH Lifestyles. RVH-Lifestyles.com

Link to comment
Share on other sites

Our plans were to go to Mayo to see John, but we have to be here in S.C. til March. And of course like the novice I am I was looking at the readings without any demand on the system. And this morning we're pretty well socked in with cloud cover and fog. So maybe tomorrow I'll be able to unhook from shore power to see what it does.

Fulltiming since 2010

2000 Dutch Star

2009 Saturn Vue

Myrtle Beach, SC

Link to comment
Share on other sites

Solar panels usually come in 12v or 24v nominal types. A 12v panel actually puts out 18-19V and a 24v panel puts out over 30. If the panels are hooked up in parallel the volts wont change. if in series the volts add up. I have 2 24v panels in series and get about 60v into the charge controller. Efficiency of panels depends strongly on the angle to the sun as oscarvan said . A 120watt panel will only supply 120 watts if its 90 degrees to the sun - if panel is mounted on roof that means only if sun is directly overhead. Any other time efficiency will be less and panel may only put out the 10-15% that pinger mentioned. Current flow to the battery depends on the battery state of charge. If battery is low the charge controller will put maximum current to the battery, As the battery charges the voltage applied will increase to 14.3v but the current will decrease. When battery is fully charged voltage drops to 13.3v just to maintain charge. You should have a switch on your controller that displays battery voltage, solar panel current and charging current. If my reading of the manual is correct the following is true. Solar panel current is what the panels are producing, charge current is what the controller is sending to the battery. Charge current can be above or below solar panel current depending on the battery state of charge. Manual is available online here http://www.blueskyenergyinc.com/uploads/pdf/Manual_BSE_SB50.pdf.

Link to comment
Share on other sites

So maybe tomorrow I'll be able to unhook from shore power to see what it does.

 

This time of year, and depending on your lat/long, it's generally not an ideal time to be testing peak performance of your solar array. Sun intensity just ain't packing much of a punch even if your panels are perfectly oriented. Unless there is some blaring indication that there might be an issue, or it's impacting your camp quality, I wouldn't sweat it... let March roll around then drop in (with an appointment) and let John Palmer give it a look see. I haven't knowingly seen any of his work, but it sounds like Jack has confidence in him and I can't imagine he would charge you much to do a systems check.

Link to comment
Share on other sites

panel may only put out the 10-15% that pinger mentioned.

 

I believe Pinger was referring to panel efficiency with that figure... the percentage of total UV light that can be converted to electricity by a solar array... not the percent of rated power production. If it's a cloudless day and my array has any overhead contact with the sun at any angle, I would be very concerned if it was producing below 15% of rated.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


RVers Online University

campgroundviews.com

RV Destinations

Find out more or sign up for Escapees RV'ers Bootcamp.

Advertise your product or service here.

The Rvers- Now Streaming

RVTravel.com Logo



×
×
  • Create New...