Renogy 200 Watt 12 Volt Mono Solar Panel, Compact Design, High Efficiency

Tim R

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I bought two of these panels and had one out in the direct sun today. Call me greedy, but the max I saw this panel deliver was 120 watts. I am talking Austin, Texas, direct sun at 1400 with the panel tilted to as close to perpendicular as I could get it with a straight stick. Temps were in the upper 60's to low 70's with a 5 knot wind coming at about a 45 towards the rear of the panel, so air was circulating behind the panel.

I bought 200 watts and I got 120. Am I being greedy or should I send it back?
 

snoobler

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Ah. There's the problem. The Electrodacus has very poor solar charging capability. It is about 30 year old charging technology. They are neither PWM nor MPPT, but simply a relay that shorts the panel to the battery, and you MUST use the correct panel voltage for your battery.

The most you will get out of your panel is Imp * battery voltage.

200W panel example:
Vmp: 18V
Isc: 11.1A

The MOST you'll ever see out of that panel is:

14.4V * 11.1A = 160W.

It's not the fault of the panel. Any panel you attach will suffer.

If you put a 250W 24V panel on a 12V system:

250W panel:
Vmp 36V
Isc: 6.94A

Best you'll ever see:

14.4V * 6.94A = 100W

In both examples, I've used a typical battery peak charge voltage. Change the voltage, and the power changes.

Electrodacus is essentially the least advanced PV solar charge controller available now in terms of technology.

If you want to get 200W out of that panel, you need to get a MPPT controller and use the SBMS0 to cycle the controller off.

Electrodacus is a cool piece of hardware, but this is a huge deficiency IMO.
 

snoobler

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You should test the Voc and Isc with a voltmeter/ammeter to confirm the panel's performance.
 

snoobler

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This is a known thing.

He justifies it here:


He claims MPPT cost is never justified because PV is so cheap and capacitors can't possibly last 25+ years (never mind that quality inverters last that long, and they have capacitrs). It's cheaper to buy 25% more panels than you need and use an electrodacus than it is to buy the panels you need + MPPT.
 

Tim R

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I have to agree with him on the financial points. MPPT controllers are expensive, not all that efficient and fail. I've been in the electronics world since I started thumping tubes as a 12 year old in my pop's tv shop. Electrolytic caps do not last 25 years. No way, no how. Ceramic caps do, but electrolytic caps not only dry out but loose performance while they dry out. Keeping in mind he comes from a stationary system.

I am measuring an apparent loss of 40% from stated capacity on my panels. That isn't even close to the difference shown in the comparison, which diminishes as panel temp increases. There is something else that is going on here with such a large loss. I don't have a VOM that is capable of more than 10amps direct so I will have to figure something else. Thanks for the link to the video, it has me more certain of my choice of the SBMS0 than ever.
 

snoobler

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I have to agree with him on the financial points. MPPT controllers are expensive, not all that efficient and fail.

That's just false. They are the only SCC that has the potential to deliver the full panel power available. Period.

I've been in the electronics world since I started thumping tubes as a 12 year old in my pop's tv shop. Electrolytic caps do not last 25 years. No way, no how. Ceramic caps do, but electrolytic caps not only dry out but loose performance while they dry out. Keeping in mind he comes from a stationary system.

As someone in the electronics world since before there was air, you should understand the limitations completely... Power = voltage * current.

Have you confirmed you're receiving 1000W/m^2 insolation on the panel? 1400 is 2 hours past peak solar. Are your skies crystal clear? No airborne particulates?

Given that you didn't test the panel, I'm guessing you haven't confirmed your solar conditions.

I am measuring an apparent loss of 40% from stated capacity on my panels. That isn't even close to the difference shown in the comparison, which diminishes as panel temp increases. There is something else that is going on here with such a large loss. I don't have a VOM that is capable of more than 10amps direct so I will have to figure something else. Thanks for the link to the video, it has me more certain of my choice of the SBMS0 than ever.

Another cultist is born. Good for you. Consider if you're being objective:
  1. Have you tested the panel? No.
  2. Have you confirmed your solar insolation? No.
  3. Have you accepted that the Electrodacus does not have the potential to capture the full panel output or anywhere near it based simply on the power equation, P = I * V (panel current * battery voltage)? Doesn't sound like it.
But something must be wrong with the panel?
 

Tim R

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That's just false. They are the only SCC that has the potential to deliver the full panel power available. Period.



As someone in the electronics world since before there was air, you should understand the limitations completely... Power = voltage * current.

Have you confirmed you're receiving 1000W/m^2 insolation on the panel? 1400 is 2 hours past peak solar. Are your skies crystal clear? No airborne particulates?

Given that you didn't test the panel, I'm guessing you haven't confirmed your solar conditions.



Another cultist is born. Good for you. Consider if you're being objective:
  1. Have you tested the panel? No.
  2. Have you confirmed your solar insolation? No.
  3. Have you accepted that the Electrodacus does not have the potential to capture the full panel output or anywhere near it based simply on the power equation, P = I * V (panel current * battery voltage)? Doesn't sound like it.
But something must be wrong with the panel?
Ok, calm down. Clearly you are passionate in your opinions and believe them above all else. Thank you for your opinions and your efforts to convert me to your positions, but I think I'll pass for now. As a moderator I would think you would be a little less aggressive. Something you might consider going forward.
 

GXMnow

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You have been told what to check and some things about your gear and the real world, and still say your panel is bad, without doing the tests.

Even the best solar panels rarely ever will hit the rated STC power levels. This is why most people will over panela bit. In my case, I have 300 watt panels, connected to 240 watt Enphase iQ7 microinverters. It takes a very clear sky and cool air for the panels to exceed the 240 watts of the inverters, but it does happen from time to time and I can see the output curve flatten off near solar noon when the panels are making a little over 240 watts. So most days, my panels do not hit 80% of STC rated power, and that is completely expected. STC is in perfect conditions with cool panels and perfect full sun, directly flat on to the face of the panel. Knowing the limitation of the Electrodocus charge controller, it looks like your panel is doing just fine.

A quality MPPT controller can turn over 95% of the solar panel power into battery charging power. This is done by using a DC-DC converter to step the voltage down while boosting the current. Some power is lost to the control processor that is optimizing the voltage and current tracking. That faster it can adjust, the more power the processor will take. But only having to adjust every few seconds is not a lot of processing power compared to a cell phone. How fast does the angle of sun change on a solar panel? Passing shadows from clouds etc. may need a quicker adjustment, but it still is not a big problem.
 

snoobler

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Ok, calm down. Clearly you are passionate in your opinions and believe them above all else. Thank you for your opinions and your efforts to convert me to your positions, but I think I'll pass for now. As a moderator I would think you would be a little less aggressive. Something you might consider going forward.

Completely calm here. I'm concerned about objective data and facts, not speculation based on false confidence in a product and a lack of understanding. If my opinion is not based on known hard facts, I'm extremely receptive to different opinions as I accept my ignorance on the matter. These aren't opinions expressed in this thread. They are hard facts.

Your panel may be bad. You have zero evidence indicating it is bad. There is indisputable evidence the Electrodacus has zero potential to extract 200W from a 200W panel and is limited to about 80% rated power under ideal conditions at MAXIMUM battery voltage. At lower voltages and less-than-ideal conditions, it's lower. Right now the evidence indicates you were testing in unknown conditions with a device that can't extract 200W from a panel.
 

Tim R

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Hold on everyone. I am having trouble finding where I state the panel is bad. That was a question, that's all it was. A question.

I implicitly stated just three things.

1. My 200 watt, 12 volt Renogy panel is delivering 60% of rated, in direct sun, (that means no clouds), and other environmental's.
2. Electrolytic Capacitors fail and will never last 25 years, (none that are available on the market anyway).
3. MPPT Controllers fail and will never last 25 years because they contain electrolytic capacitors, (see #2).

What I did not say was "my panel is bad".

With that said, unless you are going to give me two, (one for a backup), MPPT controllers, I will never use one, so please hold the hard sell. I chose the SMBS0 and DSSR20's because they are simple, reliable and at the very least have a chance to last as long as my panels. My bet is that most panels will rarely deliver full capacity in real world use. Place the panel in direct and perpendicular blue sky full sun, I would expect more than 120 watts, regardless of how its is connected to the battery pack. I get the hows and whys of the MPPT but can you explain how an MPPT charger would have given me 200 Watts from my panel that was in near perfect conditions, (AS STATED ABOVE in my first post), as I was in? BTW, the power peaked from 1300-1500, probably due to the drier air of afternoon. I would have been happy with 180 or even 170 watts, but 120 watts is too low. If the DSSR20 is, as you say, a piece of wire, then I would expect a 12 volt panel to charge a 12 volt battery as well as the environmental conditions allow. Maybe we need to run through and read all our comments and try to better understand what we are saying.
 

snoobler

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Hold on everyone. I am having trouble finding where I state the panel is bad. That was a question, that's all it was. A question.

I implicitly stated just three things.

1. My 200 watt, 12 volt Renogy panel is delivering 60% of rated, in direct sun, (that means no clouds), and other environmental's.
2. Electrolytic Capacitors fail and will never last 25 years, (none that are available on the market anyway).
3. MPPT Controllers fail and will never last 25 years because they contain electrolytic capacitors, (see #2).

What I did not say was "my panel is bad".

With that said, unless you are going to give me two, (one for a backup), MPPT controllers, I will never use one, so please hold the hard sell. I chose the SMBS0 and DSSR20's because they are simple, reliable and at the very least have a chance to last as long as my panels. My bet is that most panels will rarely deliver full capacity in real world use. Place the panel in direct and perpendicular blue sky full sun, I would expect more than 120 watts, regardless of how its is connected to the battery pack. I get the hows and whys of the MPPT but can you explain how an MPPT charger would have given me 200 Watts from my panel that was in near perfect conditions, (AS STATED ABOVE in my first post), as I was in? BTW, the power peaked from 1300-1500, probably due to the drier air of afternoon. I would have been happy with 180 or even 170 watts, but 120 watts is too low. If the DSSR20 is, as you say, a piece of wire, then I would expect a 12 volt panel to charge a 12 volt battery as well as the environmental conditions allow. Maybe we need to run through and read all our comments and try to better understand what we are saying.

1. At a minimum the following strongly implies you think something is wrong with the panel:

I bought 200 watts and I got 120. Am I being greedy or should I send it back?

I'm not trying to sell you an MPPT. I don't care what you buy or how you do it. I care that you make informed choices and don't pollute with misinformation.

You still don't understand that 170 or 180W isn't even possible with the Electrodacus unless you're pushing your battery voltage to damaging levels OR conditions permit a panel to notably exceed its ratings. Assuming 14.6V for LFP, you're going to get a maximum of Vmp * 14.6V. You MIGHT get a little higher then Vmp, but not much.

The vast majority of LFP charging occurs at or below 13.6V, so 13.6V * 11.1V (hypothetical panel above) = 151W MAXIMUM in perfect conditions with 1000W/m^w on the panel.

When it's not high noon, the sun is shining through progressively thicker atmosphere. Slight haze, atmospheric particulates, humidity, etc., all impact insolation.

When you purchase a panel and use Electrodacus as a charge controller, you should expect a panel's rated power to be reduced by 20-25%, and that is ONLY for PEAK battery voltage. It's simple P = I * V.
 

GXMnow

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Decent quality electrolytic capacitors can last over 25 years. Enphase warranties the iQ7 micro inverters out to 25 years, and they are up on the roof, just in the shade of the solar panels. A string MPPT controller like a Victron or Schneider may only have a 0 year warranty, but I bet those will also run much longer. I have a pair of large Mallory electrolytic caps that are over 30 years old, and they still measured about 4% over spec uF. Right on the cap is says -0 to +0% and they fell right in the middle of the range. They were used in hot equipment for 2 years, and sat in my spare parts bin for nearly 20 years after that. One of them is now acting as a filter to reduce the ripple current at the battery bank.
 

Tim R

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Decent quality electrolytic capacitors can last over 25 years. Enphase warranties the iQ7 micro inverters out to 25 years, and they are up on the roof, just in the shade of the solar panels. A string MPPT controller like a Victron or Schneider may only have a 0 year warranty, but I bet those will also run much longer. I have a pair of large Mallory electrolytic caps that are over 30 years old, and they still measured about 4% over spec uF. Right on the cap is says -0 to +0% and they fell right in the middle of the range. They were used in hot equipment for 2 years, and sat in my spare parts bin for nearly 20 years after that. One of them is now acting as a filter to reduce the ripple current at the battery bank.
Let me help you both out here. Run an interweb search for electrolytic derate. This will help with Caps on a hot tin roof. Might make a good movie too. Then run a search for electrolytic cap shelf-life. Next, search for electrolytic cap life-span calculator or just cap life-span for more general information.

With several days of study for a general understanding of the topic or spend several week and get a good understanding, you will see that a 25 year old cap is not going to work or at the very least, to be trusted as far as it can get up and walk. The electrolytic's made in the late 19th century suffered from many ills not the least of which was the theft of IP that caused a huge problem industry wide. Back then, brands like Panasonic and Nichcon were two of the few that didn't sufferer from poor electrolyte and build quality. I wouldn't even trust one from these companies to last 25 years. My view is that if you take that pair of 30 year old caps and give then a 2% ripple for a few days, if they last that long, it will help in understanding what all the research and documented studied and other related documentation on the subject are trying to convey.

I see you are using microinverters so obviously, unlike snoobler, you aren't afraid of 50 year old technology. Very commendable. I had thought about going that direction but after some research, I quickly dismissed it. I was looking at them to mitigate several problems, including shading. I can eliminate all the issues with the microinverters with the SBMS0 and DSSR20's and do so at much less cost. I look at it as moving the microinverter off the roof and inside to a normalized environment so the only electronics on the roof and in the harsh environment is the copper wire and maybe a diode or two.

My advice to the both of you is this. Brush up on your humility skills and do your research.
 

GXMnow

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As someone who has built and serviced PC's, I am well aware of the crap capacitors that destroyed many motherboards. I have seen many split, leaking, and burst capacitors. Before the theft and bad copies were thrown on the market, there were many very good and long lasting electrolytic capacitors. I actually PC motherboards that are over 20 years old and all of the capacitors are fine. Have they lost a few percent of capacitance? Maybe, but if they are just power filtering and spec'd to allow some degradation, they can remain functional for many years. Also bypassing large caps with smaller very high quality film or ceramic caps also extends the life greatly.

Your blanket statement that NO electrolytic caps will work for 25 years is false. I work in an industry where equipment is installed and forgotten until something fails. My pair of Mallory caps that I have here were manufactured in the 80's. They were in a 3 phase 7,000 watt Xenon lamp power supply. This ran for well over 10 years (could be close to 20) in that service. It was taken out of service when the theatre was remodeled and they down scaled to just 4,000 watt lamps and the newer supplies are much smaller and more efficient, so they scrapped these instead of shipping 500 pounds of old iron and copper. I yanked out components to have as spares before the were picked up by the salvage company. The cooling fan was packed with a 1/2 inch thick of grime and likely moving half the design air flow. The exhaust air out of these beasts would top 140F all day long, running over 12 hours a day. Those caps still measure within 10% of rated capacity. And this is no fluke. When run within their ratings, high quality components can last.

You can read all you want about how thing can fail, and it is true, they certainly can, but it is not a promise that it will fail. When a company sells a product with a 25 year warranty, you can be pretty sure they have done a lot of accelerated life testing to ensure they are not on the hook for a ton of replacements in a few years. The company I work for now sells audio processors. We use 3rd party sourced power supplies. We put out a bid and have them send us samples. We put them on a shake table in an environment chamber and we heat cycle and shake it while running at maximum load for days. One of the candidates failed in a few minutes. All the coils literally fell out of the PC board. A few had the capacitors burst. The one we chose actually still fell a bit short of our design life, and we had them make some changes before we would buy them. Many of those devices have now been in service for over 20 years. The original supplier stopped making the supply, and we had to find a replacement. The new one is about 60% of the size. They held up fine on our life test, so we started using them. Well, those are now over 10 years old and they are starting to have capacitor failures, but the original ones from the 90's are all still running fine. It has a lot to do with the quality of the components. When the supplier tries to cut costs, then the life span can be compromised. But if you are wiling to pay for the correct parts from a reputable manufacturer, they can last many years.

Having 16 Enphase iQ7 microinverters on my roof is actually a very reliable system that I am not worried about at all. I monitor my system from time to time and all 16 are still working perfectly after nearly 2 years. And sure, one might fail n the next year, maybe another the next year. It can happen. But here's the thing with micros.... I HAVE 16 OF THEM!! If one or two, or even three fail, there are still 13 more still making power. I can take my time, get the warranty replacement and take 10 minutes on my roof to change out the dud, when one finally does quit. Even when they do go out of warranty, each one is small and relatively cheap. If you have a big string inverter, and it has a problem, the whole system is down, NO SOLAR. My battery backup is a single Schneider inverter. I am still not totally happy with their software, and I hope they upgrade it and add some features, but the hardware is very well built using high quality components.

If we do have an EMP and it pops all of my micros, I can wire them up to charge my battery bank pretty easy while we recover from the apocalypse.

My advice to you, try living in the real world. All these failure studies are done to find weaknesses and improve the life of the final product. Some companies still push reduced cost and can suffer from cutting the line too close, but this is not the law. There are many very well made products with long lifespans, but they are not cheap on Ali Express. My one weak link is my Ji Kong BMS. It has already shut my battery backup system down once. It turned out to just be a poorly made cable, but I have my eye on a better solution. And in a pinch I was able to work around the failure, so it is not life or death, until the zombies come. As one more data point, the 600 watt audio power amp I have running my sub woofer in my system is now over 35 years old. Guess what? The original electrolytic power supply caps are still completely fine. This is an old class AB that makes plenty of heat, and has no fans. I have not measure their true capacity, but the ripple is low enough that it has no audible hum and when I shut it down, the power supply takes several minutes to come down even with bleeder resistors. True, it is not in So Cal sun on my roof, but it was not built to be there. The Enphase micros were designed and tested for that environment.
 

snoobler

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My advice to the both of you is this. Brush up on your humility skills and do your research.

No argument you present can counter the simple relationship:

P = I * V

The power of your panel with the electrodacus is limited to your panel Imp and your actual battery voltage at that moment. The best you will do is 20-25% less than rated in PERFECT conditions, i.e., where an MPPT will provide near 100% power.
 
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