Rate this 200w panel compared to two renogy 100w panels

[Etzu]

I'm looking at this panel.

200W 36 Cell 12V Nominal Solar Panel - 5 Busbar Specifications:

• Power: 200 Watt
• 5 Busbar
• Monocrystaline
• Vmp: 21.052V
• Voc: 24.335V
• Imp: 9.5A
• Isc: 9.87A
• Maximum System Voltage: 600V
• Height: 39.37 in.
• Width: 39.37 in.
• Thickness: 1.5625 in.
• Shipping Weight: 32 lbs.
• Warranty: 25 Years

And deciding whether or not two single 100w panels would be better or more efficient.

I have enough space on the roof, behind the fantastic fan for either two 100w panes or this square 200w panel. And just barely enough space for a single 100w panel in front of the fan, mounted sideways. Am I incorrect in thinking that if I were so inclined, at a later date, to add a third 100w panel, it should be matched to the first two? Or does that not matter?

[SunEagle]

One question I have is what is the cost of the 200w compared to 2 x 100w panels? Which ever is cheaper per watt is the way I would go.

[Etzu]

It's negligible. $185 for the panel, or about $100 for each 100w panel (when on sale).

[sdold]

Have you looked into two 100W panels and an MPPT controller? In good sun you're only going to get about 115 watts out of that big panel with a PWM controller on a 12V battery, maybe 180 watts with the additional 100W panel in parallel. With just two 100W panels in series and MPPT you'd get close to 200W, more than you'd get with three of them in parallel. I'm not that familiar with small MPPT controllers but the Victron MPPT 100/20 looks like it would work with two or three 100W panels, and it's not very expensive (probably about the cost of a 100W panel).

[Etzu]

So what you're saying is I'll barely get 115 watts out of that 200 watt panel. But if I get two 100w panels in series it would be closer to 180w? That's reason enough for the two single 100w panels.

[SunEagle]

Once you get to 200watts it will always make sense to use an MPPT CC then a PWM type. Otherwise you lose about 33% of your wattage due to how the PWM CC works.

[sdold]

So what you're saying is I'll barely get 115 watts out of that 200 watt panel. But if I get two 100w panels in series it would be closer to 180w? That's reason enough for the two single 100w panels.

The 180W I mentioned was about what you'd get with your big (200W) panel in parallel with another 100W panel, using a PWM charger. That's 300W worth of panels giving you 180W of charging. Now instead consider a slightly more expensive MPPT charger (perhaps $200 instead of $100) with only two 100W panels, in series instead of parallel. That should get you around 190W. And I believe the charge controller I mentioned has the capacity to add a third panel to get you around 280W. Double-check with folks here that are more familiar with small MPPT chargers, but it's something I'd be looking at if I was planning a small system.

[Yet another Yeti]

This 200W pvmodule produces 9.5 Amps * 21 Volts ≈ 200 Watts at Maximum Power (mp) .

The voltage gets reduced due to heat in summer .


Two 100 W modules produce at probably 7 Amps and 15 Volts(mp) ≈ 100 Watts .

These two in series would deliver 2*15 V and 7 A to the inverter , in parallel would send 2*7 A and 15 V to the inverter .

In summer , the heat will reduce the voltages of the 100W panels , too , but will be still above 24 V if in series .

You need to look also for the specifications of the 100W panels , and decide , if you need
12 V or 24 Volts for your devices .


By the way , what is a fantasic fan on the roof ??
Will there be shadowings ??

[Ho jo]

Most 20 amp charge controller s are rated at 260 watts. For 2 years I have used a 30 amp 100 volt mppt from epever $100. With 3 100 watt renogy panels in series. 240 watt 18 amp peaks. I also have the fantastic but mines on the table.

[Etzu]

Once you get to 200watts it will always make sense to use an MPPT CC then a PWM type. Otherwise you lose about 33% of your wattage due to how the PWM CC works.

Let's not get off track, I will be using an MPPT controller, my question isn't about the efficiency of a controller, but rather specifically if it's better to use two 100w panels VS a single 200w panel.

[Etzu]

The 180W I mentioned was about what you'd get with your big (200W) panel in parallel with another 100W panel, using a PWM charger. That's 300W worth of panels giving you 180W of charging. Now instead consider a slightly more expensive MPPT charger (perhaps $200 instead of $100) with only two 100W panels, in series instead of parallel. That should get you around 190W. And I believe the charge controller I mentioned has the capacity to add a third panel to get you around 280W. Double-check with folks here that are more familiar with small MPPT chargers, but it's something I'd be looking at if I was planning a small system.

Again, before delving into controller, let's figure out the best bet for a solar panel.

I currently I have a trimetric with a PWM controller but will switch to a MPPT shortly.

[Etzu]

This 200W pvmodule produces 9.5 Amps * 21 Volts ≈ 200 Watts at Maximum Power (mp) .

The voltage gets reduced due to heat in summer .


Two 100 W modules produce at probably 7 Amps and 15 Volts(mp) ≈ 100 Watts .

These two in series would deliver 2*15 V and 7 A to the inverter , in parallel would send 2*7 A and 15 V to the inverter .

In summer , the heat will reduce the voltages of the 100W panels , too , but will be still above 24 V if in series .

You need to look also for the specifications of the 100W panels , and decide , if you need
12 V or 24 Volts for your devices .


By the way , what is a fantasic fan on the roof ??
Will there be shadowings ??

Here are the 3 100w renogy panels I'm looking at, I'm not married to renogy, these are just examples based on the panel dimensions. With the third one being the absolute largest that would fit.

A fantastic fan is a 14" square fan mounted to the roof of most RVs. Not worried about shadowing as the fan with it's cover closed will be at the same height as the panels.

RNG-100D-R

Maximum Power at STC: 100W	Maximum System Voltage: 600V DC (UL)
Optimum Operating Voltage (Vmp): 16.4V	Open-Circuit Voltage (Voc): 21.1V
Optimum Operating Current (Imp): 6.1A	Short-Circuit Current (Isc): 6.6A
Weight: 14.3lbs	Dimensions: 41.6 X 20.7 X 1.38 In

RNG-100D-SS

Maximum Power: 100W	Maximum System Voltage: 600V DC (UL)
Optimum Operating Voltage (Vmp): 17.9V	Open-Circuit Voltage (Voc): 21.6V
Optimum Operating Current (Imp): 5.72A	Short-Circuit Current (Isc): 6.24A
Weight: 16.5lbs	Dimensions: 42.2 X 19.6 X 1.38 In

RNG-100D

Maximum Power: 100W	Maximum System Voltage: 600V DC (UL)
Optimum Operating Voltage (Vmp): 18.9V	Open-Circuit Voltage (Voc): 22.5V
Optimum Operating Current (Imp): 5.29A	Short-Circuit Current (Isc): 5.75A
Weight: 16.5lbs	Dimensions: 47.3 X 21.3 X 1.4 In

[SunEagle]

Let's not get off track, I will be using an MPPT controller, my question isn't about the efficiency of a controller, but rather specifically if it's better to use two 100w panels VS a single 200w panel.

Depending on the type of the MPPT controller it really shouldn't matter if you use a single 200w or 2 x 100w panels. With an MPPT it is Watts in = Watts out. That should equate to the best amps generated for charging.

Having 2 x 100w panels allows you to increase your pv input wattage by using the same type of panel. With a 200w you would need to go to 400w total.

Although going with 3 pv panels of any kind may limit your wiring options due to voltage.

[Ho jo]

With mppt the higher the imp volts it has to down Screenshot_20190228-101843.png convert the less efficient it will be. With 2 100 panels 38 or so to 12 is less efficient than the 200 watt 21 to 12. The loss would be in heat in the controller. And if your gonna later want 300 watts keep all the panels the same. Different imp vmp panels cost you power also.

[Etzu]

Depending on the type of the MPPT controller it really shouldn't matter if you use a single 200w or 2 x 100w panels. With an MPPT it is Watts in = Watts out. That should equate to the best amps generated for charging.

Having 2 x 100w panels allows you to increase your pv input wattage by using the same type of panel. With a 200w you would need to go to 400w total.

Although going with 3 pv panels of any kind may limit your wiring options due to voltage.

Pv? Let's pretend I'm 5.