Is this a proper amount of amps for 200w of panels?

[glassroots]

https://www.amazon.com/dp/B06VYJ8JXH/ref=cm_sw_r_cp_apa_i_2JVuFbFSW13C7

From what I've found northwestern Oregon is a much worse state for solar than Texas in general, across the board. I'm not too sure on what I could do to optimize my panels beyond adding an adjustable rack for them on top of the van, but I don't want to invest that much more into this van (maybe my next one). I think pulling power from the alternator or supplemental power like from a generator would be my best bet?

The solar situation here is just so abysmal I'm not sure it's worth modifying my current solar system too much. Even though my charge controller is only 20a, I may be able to get away with adding a 3rd panel without needing to upgrade my charge controller. I think that's really my best option for improving the solar If I did at all.

Sent from my SM-G988U using Tapatalk

 

[mjbeam64]

I have 700 watts of panels on my E250 van in Hillsboro Oregon and the most i've gotten from the SCC is around 37 amps.

 

[technerd88]

I have 700 watts of panels on my E250 van in Hillsboro Oregon and the most i've gotten from the SCC is around 37 amps.

Are they all series? or parallel?

 

[highdesertranger]

I am in eastern Oregon in moderately heavy forest about 140 miles west of Boise. I have 870 watts two 435 watt panels in parallel. I have seen 56.8 amps going in. highdesertranger

 

[theBest]

https://www.amazon.com/dp/B06VYJ8JXH/ref=cm_sw_r_cp_apa_i_2JVuFbFSW13C7

From what I've found northwestern Oregon is a much worse state for solar than Texas in general, across the board. I'm not too sure on what I could do to optimize my panels beyond adding an adjustable rack for them on top of the van, but I don't want to invest that much more into this van (maybe my next one). I think pulling power from the alternator or supplemental power like from a generator would be my best bet?

The solar situation here is just so abysmal I'm not sure it's worth modifying my current solar system  too much. Even though my charge controller is only 20a, I may be able to get away with adding a 3rd panel without needing to upgrade my charge controller. I think that's really my best option for improving the solar If I did at all.

Sent from my SM-G988U using

“[font=Arial, sans-serif]Renogy 200 Watt 12 Volt Monocrystalline Solar Starter 20A Rover MPPT Charge Controller”[/font]

[font=Arial, sans-serif]Notice the panels are “Monocrystalline”.[/font]
[font=Arial, sans-serif]These multicrystalline panels can not gather light well at low angles.[/font]

[font=Arial, sans-serif]The Bad News: There are several factors causing the low charging amperage from your panels.[/font]
[font=Arial, sans-serif]1. Monocrystalline and Polycrystalline only have a narrow angle they can gather light from for peak efficiency, 30 degrees.[/font]
[font=Arial, sans-serif]2. The angle of the sun is different in Oregon than it is in Texas.[/font]

[font=Arial, sans-serif]There are solar angle calculators online where you put in your location and time of year and the calculator will tell you what angle the sun is for that day/year. People installing solar panels use this information to place the panels in the optimum position to gather as much light as possible over time in a fixed position.[/font]
[font=Arial, sans-serif]You have a mobile installation that can alter the efficiency of the panels just by moving your vehicle.[/font]

[font=Arial, sans-serif]The panels must be pointed perpendicular to the sun. There is such a narrow angle on multicrystalline panels that in order to reach maximum efficiency throughout the day they require a motorized solar tracker that automatically tracks the sun and adjusts the panels to keep them at maximum efficiency.[/font]

The Good News: You are the automatic solar tracker. You are capable of resolving the issue of lower efficiency by modifying your current mounting system.
You can add something like piano hinges on both sides of the panels on the vehicle. You’ll have to make it so the side you raise can be decoupled from the hinge.
Search YouTube for adding tilting hardware for renogy vehicle solar panels. I’m sure there’s someone who has faced your issue and shows how they resolved it.
Find an online solar angle calculator and use it, you can’t always see the sun everyday, some days are overcast and identifying the exact location of the sun by eye can be difficult.

If your willing to buy another panel why not buy two or three Amorphous Silicon photovoltaic panels. They work well gathering light at low angles and on cloudy days.

 

[theBest]

It used to be fairly easy to find Amorphous Silicon panels made by the best manufacturers in the business. Now when I search for these panels I am horrified to find their is an absence of this product being promoted by anyone through search engines. Yes manufacturers are still making these Amorphous Silicon solar panels, an installation company near me only installs A.S. panels in all of their work.
So why the blackout on the name identifier "amorphous silicon"?

Why would a soloar panel manufacturer not tell you in all of their public space which photovoltaic material they use in their panels?

As an example, https://www.sol-go.com/the-sol-go-advantage.html

I have looked through this website looking for information that would identify what type of photovoltaic material is used in their panels. They don't even mention what PV material they use in their spec sheets. ???
What kind-of weirdness is going on?

On the sol-go website they say,

Conventional panels only retain 40% charge power under the shade of just one leaf.

This means 60% is lost to partial shading of the panel. This is a feature typical of multicrystalline photovoltaic materials like Monocrystalline and Polycrystalline.

Sol-go continues,

Sol-Go panels retain 90% charge under the same conditions.

This means only 10% is lost. This is a feature typical of Amorphous Silicon panels.

Additionally, Sol-go sells highly flexible panels, multicrystalline photovoltaic materials would fracture in flexible systems. Multicrystalline photovoltaic materials are like sheets of glass, to bend them is to break them.

Sol-go is just one company I've found, this may take some time to find more.

 

[mjbeam64]

Are they all series? or parallel?

All in series.

 

[barleyguy]

It used to be fairly easy to find Amorphous Silicon panels made by the best manufacturers in the business. Now when I search for these panels I am horrified to find their is an absence of this product being promoted by anyone through search engines. Yes manufacturers are still making these Amorphous Silicon solar panels, an installation company near me only installs A.S. panels in all of their work.
So why the blackout on the name identifier "amorphous silicon"?

On the sol-go website they say,

Conventional panels only retain 40% charge power under the shade of just one leaf.

Sol-go continues,

Sol-Go panels retain 90% charge under the same conditions.

This means only 10% is lost.

The cheap solar panels at Harbor Freight are amorphous silicon. It's significantly less efficient than mono or poly for the same size. Though it does do really well in shading as well as cloudy days. The problem is that if you're half as efficient to start with, maintaining your efficiency with shading isn't that big of an advantage.

Also, mono crystalline and polycrystalline ARE the material that those panels are made of. So it's clearly shown on the spec sheets.

 

[theBest]

It's significantly less efficient than mono or poly for the same size.

How is efficiency measured?

In 1 square meter, 3 feet by 3 feet or 9 quare feet, there is available 1000 watts of solar energy.

Multicrystalline panels, like monocrystalline and polycrystalline, are considered 25% efficient.
Amorhous Silicon panels are considered 15% efficient.

How is this % efficient number calculated?

Take a 1 square meter panel of each type photovoltaic material and measure how many watts they produce out of 1000 watts.
Mono and Poly both produce about 250 watts out of 1000 watts available = 25% efficient *in ideal conditions.
Amorphous Silicon produces 150 watts out of 1000 watts available = 15% efficient *in ideal conditions.

The BIG question answered in a few videos:
What are real world results, side by side, comparison, shoot-out...?

Thin Film Amorphous Solar Panels low light results


Canadian Prepper Compares 3 Types of Solar Panels


Amorphous Thin Film Solar Panel almost makes power in the dark


Solar panel performance shoot-out - Part 1


Solar panel performance shoot-out - Part 2


Solar panel performance shoot-out - Part 3
https://www.youtube.com/watch?v=njngahe6pKE

More a-Si panel manufacturers:
http://uni-solar.com/

Also, mono crystalline and polycrystalline ARE the material that those panels are made of. So it's clearly shown on the spec sheets.

For which? The Renogy or the Sol-go?

If you're talking about Sol-go then you better post a link because the spec sheet I found doesn't mention PV type in writing.
The pictures on the otherhand do indicate Monocrystalline by the shape of the cells.
https://duckduckgo.com/?q=spec+sheet+site:sol-go.com&t=ffab&ia=web

 

[barleyguy]

How is efficiency measured?

In 1 square meter, 3 feet by 3 feet or 9 quare feet, there is available 1000 watts of solar energy.

Multicrystalline panels, like monocrystalline and polycrystalline, are considered 25% efficient.
Amorhous Silicon panels are considered 15% efficient.

Those efficiency numbers are completely wrong, or at least not "real world". From actual datasheets of actual products, which are some of the best in their classes:

Monocrystalline: 20.38%
Amorphous: 7.9%

I concede that amorphous has good low light and shaded performance. But like I said, if it's only 38% as efficient to start with, why does that matter? If you are building a large system with unlimited roof space, and shaded performance is a significant factor, then they might be worth considering. But this forum is for vans and RVs, where roof space is not very big. In that situation, in almost all cases, monocrystalline is going to be a better choice than amorphous. Because the amorphous is going to start out almost 3 times as large in area for the same wattage, performing well in the shade isn't enough to balance that out.

http://www.xsunx.com/pdf/SpecSheetOctober28-2008.pdf
https://www.jinkosolar.com/uploads/CheetahPerc JKM390-410M-72H-(V)-A3-EN.pdf

Also, do you have a financial relationship to any amorphous solar cell vendors or companies? If so you should disclose it.

 

[theBest]

Those efficiency numbers are completely wrong, or at least not "real world". From actual datasheets of actual products, which are some of the best in their classes:

Monocrystalline: 20.38%
Amorphous: 7.9%

I concede that amorphous has good low light and shaded performance. But like I said, if it's only 38% as efficient to start with, why does that matter? If you are building a large system with unlimited roof space, and shaded performance is a significant factor, then they might be worth considering. But this forum is for vans and RVs, where roof space is not very big. In that situa ition,in almost all cases, monocrystalline is going to be a better choice than amorphous. Because the amorphous is going to start out almost 3 times as large in area for the same wattage, performing well in the shade isn't enough to balance that out.

http://www.xsunx.com/pdf/SpecSheetOctober28-2008.pdf
https://www.jinkosolar.com/uploads/CheetahPerc JKM390-410M-72H-(V)-A3-EN.pdf

Also, do you have a financial relationship to any amorphous solar cell vendors or companies? If so you should disclose it.

In describing how efficiency is measured it is easier to deal with whole numbers rather than the fractions you post. My goal was to help people understand what the efficiency calculation represents conceptually. Once you understand the concepts then anyone can plug in their real world spec numbers.

in almost all cases, monocrystalline is going to be a better choice than amorphous.

Then you didn't watch the shoot-out video where the guy shows the two panel types head to head, watt for watt, produce the same amount of energy in almost every situation.
Watt for watt, if amorphous panels are 40%-50% bigger than mono, that's 3/2 not 3/1. If 100% bigger, that would be 2/1 not 3/1.

 

[barleyguy]

In describing how efficiency is measured it is easier to deal with whole numbers rather than the fractions you post. 

So it's easier to use made up whole numbers than real world specs? It may be easier, but it's also wrong.

[quote pid='506199' dateline='1599618823']
[font=Tahoma, Verdana, Arial, sans-serif]Then you didn't watch the shoot-out video where the guy shows the two panel types head to head, watt for watt, produce the same amount of energy in almost every situation.
Watt for watt, if amorphous panels are 40%-50% bigger than mono, that's 3/2 not 3/1. If 100% bigger, that would be 2/1 not 3/1. [/font]
[/quote]


Yes, if it was only 100% bigger per watt, it would be 2:1. But if you look at the real world spec sheets I posted, the amorphous is 63x39 for 127 watts, and the mono is 79x39 for 400 watts. So the difference is 2.5:1

I'm not arguing that mono is better watt for watt for unlimited roof space. But amorphous takes up 2.5 as much roof space for the same wattage, and this a van and RV forum.

 

[Spaceman Spiff]

Then you didn't watch the shoot-out video where the guy shows the two panel types head to head, watt for watt, produce the same amount of energy in almost every situation . . .

Youtube is not known to be a disseminator of accurate testing; too easily faked.  Show me testing that has been reviewed by solar engineers and published by someone who has a reputation to uphold: university, laboratory, scientific or solar journal, etc.

 

[wayne49]

"In 1 square meter, 3 feet by 3 feet or 9 quare feet, there is available 1000 watts of solar energy"

Depends on the Sun, clouds, smoke, dust, humidity, latitude, time of year, etc. It is not a constant value.

Right now in Amargosa Valley at 15:15 the solar available is 670.00 watts/m². Peak today was 853.00 watts/m² at 12:45.

 

[theBest]

How you do that? :huh:
Link please.

Solar irradiance data for United States
https://solcast.com/solar-radiation-map/united-states/?month=2020-09#2020-09-07

Tracking the Sun
https://emp.lbl.gov/tracking-the-sun/

Solar Time, Angles, and Irradiance Calculator: User Manual
https://aces.nmsu.edu/pubs/_circulars/CR674/welcome.html

Peak Sun Hours
https://www.solarpowerrocks.com/solar-basics/peak-sun-hours/

Sketch-up Watt Extention
https://deluminaelab.com/docs/dl-light/en/watt.html

"So, if you wanted to know how much energy from the Sun was reaching the ground per minute at Sacramento, at say, precisely 10:40am on April 8th, 2015, you’d just read from the graph and find that it was in fact about 815W power over the minute, or 49 kJ energy. This is slightly lower than the other answers which quote about 67 kJ, as it was slightly before solar noon and from a location where the sun does not pass directly overhead at that time of year"
- Yuan Gao - Power Engineer (Qora)
https://www.quora.com/How-much-ener...quare-meter-per-minute-solar-constant?share=1

Panel specs and how they test
https://www.microgreen.ca/solar-panels/solar-panel-100w