2000k system only puts out 500 watt why?

[JoeBlow]

you could never get back out what you put in and you would have to position the light directly over the panel I thought of it because I seen panels tested on a video in a solar panel manufacturing plant but I don't know if they are using 500W, 1000W, or two 1000W bulbs in different light spectrums.

But if the lighting was powered by the city grid, any power would be gain. I think it would be an interesting experiment. I watched the battery climb to 13v before it was disconnected from that panel. This was only a few minute test. I think theres a significant amperage considering the light source.

[inetdog]

If it was just one or two panels, this would be easier to suspect. For the same voltage drop to have occurred in all of them seems like something more systematic.

If these were amorphous silicon (thin film) panels or other than silicon chemistry there might be a voltage variation with age.

[sensij]

If the voltage drops it is more likely an indication that one or more cells in the panel have broken and shorted out internally.

If it was just one or two panels, this would be easier to suspect. For the same voltage drop to have occurred in all of them seems like something more systematic.

[inetdog]

I have heard the opposite. That in cold temperatures one must be careful not to allow the panels to exceed the input of charge controllers because output rises at colder temperatures.

Is it possible that is what they were trying to describe?

The biggest risk is that the voltage rises above the maximum DC that the CC input can handle. That is much less likely to happen with an MPPT CC with a wide input voltage range.
The second, less credible risk is that the overall power will somehow overload the CC.
But most MPPT CCs will just adjust their operating point to take only the amount of power that they can safely handle. A PWM CC may still be OK because the available current has actually gone down.

[lkruper]

See missouri Wind and solar told me the panel puts out more power as it warmed up or gets hotter and when the panel get cooler or colder it puts out less power. So they lied to me correct?

I have heard the opposite. That in cold temperatures one must be careful not to allow the panels to exceed the input of charge controllers because output rises at colder temperatures.

Is it possible that is what they were trying to describe?

[inetdog]

See missouri Wind and solar told me the panel puts out more power as it warmed up or gets hotter and when the panel get cooler or colder it puts out less power. So they lied to me correct?

Well, it was either deception or ignorance. Not sure which is worse.
The current goes up with temp at the same time the voltage goes down. But for the panels I have looked at the net power goes down with temperature because the voltage change is a larger percentage than the current change.

People keep proposing innovative ways of trying to cool the panels during use, but the added complexity seems to make all of he ways less desirable than you might think at first.

[sensij]

What kind of grounding is used in this system? PID could affect Voc, and these look like generic panels that may not be as resistant as some others.

[charles2,david000k]

It is not at all normal for the panel voltage to drop over time, especially not in the first few years (if we are talking about a crystalline silicon panel). As the panel degrades with time the current at the same light level will decrease. If the voltage drops it is more likely an indication that one or more cells in the panel have broken and shorted out internally.
Or, of course, that the average panel temperature has gone up considerably. Increased temperature can conceivably drop the output voltage by as much as 10% in a very hot climate with poor air circulation around the panel. But when the panel is cool first thing in the morning the voltage should be close to what it started off at when new.

See missouri Wind and solar told me the panel puts out more power as it warmed up or gets hotter and when the panel get cooler or colder it puts out less power. So they lied to me correct?

[inetdog]

This whole 34 volt thing really bugs me. Is this really normal behavior for solar panels to drop off 4 volt's with in the first year? Granted I can not get a accurate reading on my current but when Missouri Wind and Solar tested the panels all they could get on current was 5 amps at 33 volts no higher on any of the panels and they told me the panels are still working properly and within warranty limits. I mean I don't know jack about solar compared to you guys but it just doesn't seem right. I know they drop off but from my understanding it's over a 25 year span at a slow decline not rapid drops. I mean who's right the licens tech who came out spent two days going over everything and told me the panels and cc are bad or the unlicensed salesmen. My gut tells me to listen to the guy who went to school but then again he could of slept through class. 34vX5a=175w That a 75 watt drop during peak time.

It is not at all normal for the panel voltage to drop over time, especially not in the first few years (if we are talking about a crystalline silicon panel). As the panel degrades with time the current at the same light level will decrease. If the voltage drops it is more likely an indication that one or more cells in the panel have broken and shorted out internally.
Or, of course, that the average panel temperature has gone up considerably. Increased temperature can conceivably drop the output voltage by as much as 10% in a very hot climate with poor air circulation around the panel. But when the panel is cool first thing in the morning the voltage should be close to what it started off at when new.

[charles2,david000k]

lol, thats funny you said that. I just watched somebody hook a 100watt panel up under a 1,000 hps light and it actually started to charge the battery. I didnt see any amperage tests but it would be interesting to see what it would do. A factory that uses HID lighting could recoupe their power loss if you could establish a good amp flow.

you could never get back out what you put in and you would have to position the light directly over the panel I thought of it because I seen panels tested on a video in a solar panel manufacturing plant but I don't know if they are using 500W, 1000W, or two 1000W bulbs in different light spectrums.

[JoeBlow]

Just a thought but would a 1000 Watt high pressure sodium or metal halide grow light work to cut out the sun shading and angle problem?

lol, thats funny you said that. I just watched somebody hook a 100watt panel up under a 1,000 hps light and it actually started to charge the battery. I didnt see any amperage tests but it would be interesting to see what it would do. A factory that uses HID lighting could recoupe their power loss if you could establish a good amp flow.

[charles2,david000k]

You are really hung up on the wrong thing. A properly functioning panel would never operate at 38 V or 34 V, unless it is extremely cold out. The panel produces maximum power at Vmp, which for your panels is 30.9 V. If they are warmer than 25 deg C, that value will drop. The panels in my grid tie array have a Vmp of 30.3, but on a hot summer day, they will drop down to around 25 V.

The only way to get a panel to operate consistently at Vmp is to have a charge controller (or grid-tie inverter) with an MPPT function. Without MPPT, you can sort of get close with 24 V panels that have a Vmp of 34-35 V... by the time you factor in temp corrections, the actual maximum operating voltage point should be close to the ideal charge voltage.

The fact you are measuring ~34 Voc on all the panels *could* be a sign of degradation. It could mean that your meter is pulling a bit more current than it should when it is making the measurement, and dragging the voltage down. Do the leads get warm at all? However, until you have a good way to measure operating voltage and current and be able to track it over time *and* have an mppt charge controller that is attempting to get the maximum power from the panels, it is almost impossible to prove that the system is or is not at warrantied performance. The only way I know how to do it is to track and plot that power over time, and compare it to what a PV modeling system would show the power to be under those conditions and with certain loss assumptions. Truly clear sky day-to-day comparisons can be powerful, once you understand the effects of temperature and solar position on the array's output.

Just a thought but would a 1000 Watt high pressure sodium or metal halide grow light work to cut out the sun shading and angle problem?

[JoeBlow]

Mine is set up in disconnect mode and the inverter monitors the bank power also if the bank falls to a certain voltage it uses grid power to feed the home and charge the batteries until the bank holds a proper voltage what those inverter set points are I have no clue at the moment but I do know the cc will read 28v at night when the bank goes dead and the inverter start to charge the bank it also has a desulfate setting which you have to manually activate. The inverter is picky when it comes to the battery that's another reason I had to swap out the batteries the first time.

add later. What are your peak charging amps/current going through the solenoid to your battery bank? I was told by the retailer not to feed no more than 200 amps to the solenoid with 4 AWG braided copper tin coated wire but that is just what I was told.

I questioned the reliability of this solenoid for obvious reasons. They assured me it would support my future plans, which isn't nearly 400, more like below or at the 200 mark. I would imagine the 400amp would be a peak load, not sustainable. I notice heat build up in the solenoid which in my eyes it tells me that I am burning power, however most CC units will heat up. I have 100Ah running on my system now and they are charged by 2pm after 60% drain the night before. This is while the house is running on the inverter. I don't run major appliances on it right now because I need to expand. My point in this blah blah! lol, is if I can maintain and nearly over fill my 100ah storage in the afternoon while in use, I feel that your battery setup is too small for your needs. I am not a pro, I am about 5 months into a really smooth solar life. I installed everything and after I fried my first set of batteries I realized I needed more AH to back up what I took. Since then it has been an effortless system.

6 100W 12V Renogy Panels
100ah storage
I pull about 10amps with my inverter while my batteries slowly climb up.

Inverter is 2,000watt
I pull a little over 30amps during average day

[sensij]

This whole 34 volt thing really bugs me. Is this really normal behavior for solar panels to drop off 4 volt's with in the first year? Granted I can not get a accurate reading on my current but when Missouri Wind and Solar tested the panels all they could get on current was 5 amps at 33 volts no higher on any of the panels and they told me the panels are still working properly and within warranty limits. I mean I don't know jack about solar compared to you guys but it just doesn't seem right. I know they drop off but from my understanding it's over a 25 year span at a slow decline not rapid drops. I mean who's right the licens tech who came out spent two days going over everything and told me the panels and cc are bad or the unlicensed salesmen. My gut tells me to listen to the guy who went to school but then again he could of slept through class. 34vX5a=175w That a 75 watt drop during peak time.

You are really hung up on the wrong thing. A properly functioning panel would never operate at 38 V or 34 V, unless it is extremely cold out. The panel produces maximum power at Vmp, which for your panels is 30.9 V. If they are warmer than 25 deg C, that value will drop. The panels in my grid tie array have a Vmp of 30.3, but on a hot summer day, they will drop down to around 25 V.

The only way to get a panel to operate consistently at Vmp is to have a charge controller (or grid-tie inverter) with an MPPT function. Without MPPT, you can sort of get close with 24 V panels that have a Vmp of 34-35 V... by the time you factor in temp corrections, the actual maximum operating voltage point should be close to the ideal charge voltage.

The fact you are measuring ~34 Voc on all the panels *could* be a sign of degradation. It could mean that your meter is pulling a bit more current than it should when it is making the measurement, and dragging the voltage down. Do the leads get warm at all? However, until you have a good way to measure operating voltage and current and be able to track it over time *and* have an mppt charge controller that is attempting to get the maximum power from the panels, it is almost impossible to prove that the system is or is not at warrantied performance. The only way I know how to do it is to track and plot that power over time, and compare it to what a PV modeling system would show the power to be under those conditions and with certain loss assumptions. Truly clear sky day-to-day comparisons can be powerful, once you understand the effects of temperature and solar position on the array's output.

[charles2,david000k]

I just wanted to step in and defend this little solenoid charger. It is actually a decent charger and can handle 400amp. The instructions show that you install this item in a way that the charging battery bank never gets fully disconnected and the "dump" load just saps the power away from the battery. I realized this and tested the relay in a different way. The top lugs are simply a cutoff "to keep the on/off thing more simple" which in default setting it "makes a connection" all the time, then it will cut off the supply to the batteries. The lower lugs are supposed to be used for a system requiring a divert, which is "disconnected from" each other by default. On one lug the solar panels are connected and then it runs from there to the battery remaining always connected. The other lug goes to your divert system. This is the way the instructions tell you to do it.

Here's what I did.
I ran two wires from my panels fuse, one to a top lug, and the other to a lower lug. then I ran my "Primary bank" to the upper lug, and my divert to the lower lug. Now when my system diverts it is completely disconnected from one another when they are charging. I have found that this work perfectly and I get a great charge and use from my batteries. What I would suggest though is that a better charge controller is used, these solenoids can be used on any charger (I have seen them used with normal CC of all types. never tried) I am going to test that option too.

BTW I am at 600watts in panels and I can keep (with divert to second bank) 7 nearly charged by the end of the light period. The original poster needs a little more storage for his system. My first set of batteries were FRIED! because of my ignorance and I learned that I needed more. I would suggest double checking if not triple checking the batteries health with a battery tester. You can get one at Harbor freight cheap.

Lol, sounds like I predicted that one

Mine is set up in disconnect mode and the inverter monitors the bank power also if the bank falls to a certain voltage it uses grid power to feed the home and charge the batteries until the bank holds a proper voltage what those inverter set points are I have no clue at the moment but I do know the cc will read 28v at night when the bank goes dead and the inverter start to charge the bank it also has a desulfate setting which you have to manually activate. The inverter is picky when it comes to the battery that's another reason I had to swap out the batteries the first time.

add later. What are your peak charging amps/current going through the solenoid to your battery bank? I was told by the retailer not to feed no more than 200 amps to the solenoid with 4 AWG braided copper tin coated wire but that is just what I was told.