Can't get enough power from my newpowa panels

[fat_old_sun]

Side by side comparison, Newpowa was producing about 20% less than Renogy solar panels using the victron MPPT controller. Newpowa also got hotter and the steady state was lower by about 20 to 25% less than Rnogy. I want to do this on a sunny day so I can take few pics and show you guys but i haven't had the time nor the weather. I'm hoping on a sunny day the difference won't be as dramatic. I now have a much deeper appreciation for what Will does.

Hi Abby, most of us here are geeks & we would like to see #"s, lots of it. Instead of posting relative figures like 25% less, etc, how about posting actual volts, amps, etc? Since you have two similarly rated panels, you may use one as a reference. Prop up both panels in the same orientation to the Sun & leave them out for 15 to 20 mins. Then measure the short circuit currents of both panels & the open circuit voltages. Post these #'s along with a clear legible photos of their nameplates. Thanks.

edited 255 to 25%

 

[Freddmc]

What is the difference between short and open circuit voltage?

 

[tictag]

There isn't a 'Short Circuit Voltage', do you mean 'Short Circuit Current'?

Voc (Voltage Open Circuit) is the maximum voltage your panel (or array) produces i.e. when there is nothing connected to it. This parameter is used when considering the Maximum PV Voltage supported by your SCC (Solar Charge Controller)

Isc (Current Short Circuit) is the maximum current your panel (or array) produces i.e. when there is a direct short across the panel/array. This parameter is used when considering your PV cable specifications and (if required) protection devices.

Voc and Isc lie at the extremes of your panel/array's 'VI' performance curve:



Let me know if you want a further explanation about Vmp/Imp/Pmp.

 

[fat_old_sun]

What is the difference between short and open circuit voltage?

Open circuit voltage is the absolute highest voltage a cell (or a panel) can develop. This is similar to the water pressure in a garden hose when you plug the end with your thumb.

Short circuit current is the absolute max. current (electrons) a cell can produce. This occurs when you remove all external resistance to to current flow by shorting the + & - terminals together; hence the term short circuit current. The electrons flow with very little "oomph". This is similar to the max water flow (gpm) when you let the water flow freely. The water does not come out with a lot of force.

What we are interested in is the ability of the solar current to do some work. This ability is determined by the product of current (# of electrons) & the pressure (voltage) with which the flow happens. In the garden hose analogy, this would be similar to putting your thumb just so that the water flow is high in gpm & pressure. For a panel, this would be the Vmp, Imp & Pmp points in the illustration of @tictag. A device that adjusts the external resistance/conductance to extract the max power is called maximum power point tracking device.

 

[upnorthandpersonal]

By the way, the diagram that @tictag posted also clearly shows the maximum power point, and should help clarify what an MPPT (maximum power point tracking) charge controller really does.

 

[Ped]

School must have gotten busy

 

[Ped]

Bump...really interested to see results as this brand is popular

 

[Ped]

I suspect there might be some confirmation bias...

 

[Abby Smith]

Sorry Folks, I have been back home since school was over and havn't done much lately.
Things are looking better in Wa, but not for the rest of the country. Hope everyone is staying safe.

 

[Ped]

Where did all the other posts go? Lol

 

[fat_old_sun]

I ordered two Newpowa 100 Watt panels. Tested both today. Both performed slightly better than the specs. The sky was clear, but not crisp - not exactly an AM1.5 conditon.

 

[Forbisher]

Sorry Folks, I have been back home since school was over and havn't done much lately.
Things are looking better in Wa, but not for the rest of the country. Hope everyone is staying safe.

Looks like no testing results of Newpowa panels are going to be shared here.

 

[RCinFLA]

From the picture, can count 18x4 (72) cells but that doesn't stop them from connecting some of them in parallel & series in panel hookup. Look like their 12v battery intended panels are definitely doing that.

Did you check open circuit voltage (Voc) on panel to be sure what you are dealing with? If 72 series should get about 43-46 vdc Voc.

Newpowa site did not seem to have any 100w panels that looked like that. Ones that looked similar had 4x16 cell arrangement. They sell both poly and mono panels so would be good to know type. Poly's often throw in a few more series cells to make up for lower voltage per cell.

 

[Forbisher]

From the picture, can count 18x4 (72) cells but that doesn't stop them from connecting some of them in parallel & series in panel hookup. Look like their 12v battery intended panels are definitely doing that.

Did you check open circuit voltage (Voc) on panel to be sure what you are dealing with? If 72 series should get about 43-46 vdc Voc.

Newpowa site did not seem to have any 100w panels that looked like that. Ones that looked similar had 4x16 cell arrangement. They sell both poly and mono panels so would be good to know type. Poly's often throw in a few more series cells to make up for lower voltage per cell.

Voc on these 100 watt Newpowa are 20.23V which is lower than most 100 watt panels.
Imp is 5.89A and Vmp is 17V = 100 watts.