Solar panel not giving me the amps - 170w and getting maybe 1.7a in full sun

[DangerousPirate]

I am aware that I am in NW England during spring and I don't expect the absolute maximal possible output (14.2 amps btw), but I do expect a little more than 1.7 amps.

Could my solar panel be faulty? I don't see any faults on the panel, and it's clean as well. One of the connectors sort of broke at the plastic bit that holds the two pieces together, but they are touching well and I taped them so they don't slide apart. I am mentioning it to find a culprit, but I really don't think this should be a big deal as long as the metal inside has good connection.

Panel is a renogy 170w flexi with a renogy voyager PWM charge controller. I know, not MPPT but still shouldn't be that terrible.

I ran the batteries low overnight to get to 12.3 or 12.2 or something like that. That way I could see the amps rise. But no, they don't. I get the same sort of output.

Any clues?



I tried it differently like this as well


The readings, both, were taken BETWEEN clouds when the sky was unobstructed.

 

[Daverw]

When I had a 150w flexible panel I never got more than 35w out of it even in full sun, this was especially poor if the panel was not tilted 90 degrees to the sun, changed to fixed frame panels and regularly get 70% of capacity, now have two panels with each its own mppt controller

 

[DangerousPirate]

When I had a 150w flexible panel I never got more than 35w out of it even in full sun, this was especially poor if the panel was not tilted 90 degrees to the sun, changed to fixed frame panels and regularly get 70% of capacity, now have two panels with each its own mppt controller

Hm that sounds very disappointing. I do have a rigid one around as well, 100w. But a connector for the solar broke and I have to replace it. Might harvest it from rigid or something.
Are flexible ones really that bad?

 

[Daverw]

I’ve never seen good reports from flexible panels, also panels need to be as cool as possible and flexibles don’t have this option as they are to fitted flat on surface, they are also significantly more expensive

 

[dunedin]

I’ve never seen good reports from flexible panels, also panels need to be as cool as possible and flexibles don’t have this option as they are to fitted flat on surface, they are also significantly more expensive

Or you are just not remembering or dismissing the many good reports on flexible panels. Ours are fitted to the sprayhood and work well.
Small and neat and we don't want a gantry. Just sold off the only rigid panel which was a pain, literally, due to hard metal corners.

 

[Daverw]

Perhaps fitting them on to the spray hood is the answer as it helps cool the underside, I think flexible technology is behind rigid a bit as well

 

[DangerousPirate]

Hm. I thought flexible ones were just horrible because they flex and then don't get full sunshine. Guess I just didn't buy the right thing....

Means I will have to dig up the other rigid one and use it as my temporary power source. Just 100w and I hope it's better than 1.5 amps.

I'll have to figure out a solution one day, maybe I'll do a solar arch and put a couple up there. I just want to keep being able to use the aft gate and boarding ladder, too.

 

[Daverw]

Can you fit on side guard rails and pivot up when needed, that looks a popular option.
We have peaked today at 8.5 amps from 250 w panels

 

[DangerousPirate]

Can you fit on side guard rails and pivot up when needed, that looks a popular option.
We have peaked today at 8.5 amps from 250 w panels

I don't think I'll do that permamently. Only as a temp solution really. But not with this flexi one tbh. It's just a terrible output. 170w and I get .... drum roll please ..... 1.6a.

 

[Refueler]

Ampas alone means nothing ... it has to be viewed along with the voltage state of the batterys its charging.

The only time you will see high ampage is when batterys are so low - their resistance to charge (ie voltage) is low .. as the voltage climbs - the amps will reduce accordingly.

1,7A from such a panel - if you batts are in a reasonbale charge state is not actually that bad ..

 

[DangerousPirate]

Ampas alone means nothing ... it has to be viewed along with the voltage state of the batterys its charging.

The only time you will see high ampage is when batterys are so low - their resistance to charge (ie voltage) is low .. as the voltage climbs - the amps will reduce accordingly.

1,7A from such a panel - if you batts are in a reasonbale charge state is not actually that bad ..

At 12.3v?

 

[PaulRainbow]

At 12.3v?

How many watts and volts at the solar panel ?

 

[DangerousPirate]

How many watts and volts at the solar panel ?

Don't remember. But it was not taht high. Corresponded with the amps.

 

[wonkywinch]

Try pointing it more like 30 degrees from vertical, not flat as you have. Not sure where in the NW you are but for Newcastle, the sun only reached 30 degrees altitude today. The panel will be more efficient pointing at the sun rather than straight up.

 

[PaulRainbow]

Don't remember. But it was not taht high. Corresponded with the amps.

Need more information to make a meaningful comment.

Volts and watts at the panel. ?
How long are the cable runs from panel to controller and controller to batteries ?
Cable sizes ?

Semi flexible panels are meant to be mounted on slightly curved surfaces, not moved around the deck constantly flexing in different ways. most are not supposed to be bent concave, if you continue as you are, they won't last very long.

 

[DangerousPirate]

Need more information to make a meaningful comment.

Volts and watts at the panel. ?
How long are the cable runs from panel to controller and controller to batteries ?
Cable sizes ?

Semi flexible panels are meant to be mounted on slightly curved surfaces, not moved around the deck constantly flexing in different ways. most are not supposed to be bent concave, if you continue as you are, they won't last very long.

I will run a test again tomorrow and note the volts and wattage at the panel. I forgot to make a note earlier.

Cable size from the battery to the controller is 12awg, same as the solar panel cables (although they are a bit stiffer). Cable is new, tinned core. Runs about 2m to the battery.
Cable to panel is maybe 3-4 metres.

And I don't plan on using them like that very long. It's just a temporary solution, and I was mostly testing them out tbh. I just wanted to see waht kind of amps I can get in the current weather, and just think 1.7a is too low for what should be possible.

 

[OCuea]

Why do solar panels need to be kept cool? I thought I read that it is the IR radiation (not visible light or uv) that makes them work. Is it a very vaguely like the peltier chip ‘idea’?

 

[Daverw]

The panel efficiency drops as the temp increases, this is one of the reasons a solar farm has not been built in the Sahara desert

 

[OCuea]

The panel efficiency drops as the temp increases, this is one of the reasons a solar farm has not been built in the Sahara desert

How bizarrely and almost paradoxical. Interesting to say the least. I have seen photos of arrays in hot countries with focal points etc etc. now I wonder if they use water cooling or something. Very interesting thankee

 

[Daverw]

Hot water or steam arrays to provide turbine power