300w ebay panels?

[OffGridForGood]

Since this is on a mast, would it be better to use 3 x 100W panels instead of 1 x 300W?
ie would spacing 3 100W panels up a mast be less wind load, spread out more, and less likely to twist the mast in the wind?
With three 100W panels, each could be oriented differently, SE/South/SW maybe this provides better all day power.
Just wondering if a single 300W panel is really the best solution.

 

[masonsdad]

Since this is on a mast, would it be better to use 3 x 100W panels instead of 1 x 300W?
ie would spacing 3 100W panels up a mast be less wind load, spread out more, and less likely to twist the mast in the wind?
With three 100W panels, each could be oriented differently, SE/South/SW maybe this provides better all day power.
Just wondering if a single 300W panel is really the best solution.

It is actually a 40 ft triangle tower in a remote setting about an hour away. It will have remote monitoring via microwave link radios. You make a valid argument. Any thoughts on makes of 100w panels?

 

[Mattb4]

I'm new to all of this. Any suggestions on manufacturers? I have limited space, so one 300w panel is probably the most I can fit due to wind load restrictions on my tower site.

With needing only one the difficulty with buying the big name brands is shipping and the fact most will not sell just one.

Taking a quick look on Amazon. BougeRV has a 300w panel with free shipping for $370 Since its measurements gives it at 1.4 square meters it should not be a problem with false wattage claims. Plus I have had good dealings with Bouge in the past when they replaced a bad SCC for me without any argument or need to ship back the old. https://www.amazon.com/BougeRV-Mono...=1684071614&sprefix=300+w,aps,344&sr=8-5&th=1

 

[venquessa]

I bought a cheap 330W panel from Amazon.

166x100cm = 1.66m^2. 1000W * 1.66 = 1660W * 21.4% (it's claimed efficiency) is 355W. However, there is white frame, unused area, busbars and gaps etc. So I think 330W is perfectly reasonable. It has spiked to 405W during "cold front" conditions with towering white cloud reflecting. (Craig solar, no affiliation).

For a 1 meter panel to claim more than about 210W ... won't be using the standard lumminance of 1000W/m^2. The true maxima depends on a massive amount of variables, but could easily be 1400W. However, there is a standard for a reason.

It's not dual sided is it?

Also, one thing that struck me. If you are not limited to a vehicle/RV/boat don't buy vehicle panels. They are not as "dense" as larger panels. So it's a bit wasteful to install 8 or 10 160W panels, when you could install 4x 360W panels. It's better use of space and cheaper.

 

[12VoltInstalls]

It is actually a 40 ft triangle tower in a remote setting about an hour away. It will have remote monitoring via microwave link radios. You make a valid argument. Any thoughts on makes of 100w panels?

I have been happy with windyNation and Rich Solar 100W panels. A pair of panels from either vary over time $160-$240 and these polycrystalline panels are $150 right now. Don’t know if Will’s site has the pairs for a discount currently. I have several of these, several windyNation, plus four windyNation monocrystalline panels (slightly smaller).

With needing only one the difficulty with buying the big name brands is shipping and the fact most will not sell just one.

There’s stuff around here and there.
I bought six new NIB 315W REC Solar panels for $800 and I had to drive 50 miles to get them and recently picked up 41 used 60W thinfilm panels for free that test fine.

With three 100W panels, each could be oriented differently, SE/South/SW maybe this provides better all day power.

This is what I would do: but maybe do four. 1 SE, 2 S, 1 SW and parallel them.

 

[Mattb4]

I have a variety of inexpensive solar panels from different sellers bought slowly over several years. None arrived broke which considering my remote location is rather amazing. Not only is there my dirt County road of several miles for the Fed Ex trucks to travel but all the other ones that they have to traverse before they get to me. They all came with free shipping.

They all seem to work within expectations though my latest purchase (4 in 1) the results are not in yet due to persistent poor weather. I figure if I get 75% on average it is good. I have seen more than 100% during cloud lensing effect on my older panels.

One thing that needs to be kept in mind is what voltage is needed. If Masonsdad needs a higher voltage than going with several smaller watt panels in series may be a better option than one large panel.

 

[masonsdad]

I have a variety of inexpensive solar panels from different sellers bought slowly over several years. None arrived broke which considering my remote location is rather amazing. Not only is there my dirt County road of several miles for the Fed Ex trucks to travel but all the other ones that they have to traverse before they get to me. They all came with free shipping.

They all seem to work within expectations though my latest purchase (4 in 1) the results are not in yet due to persistent poor weather. I figure if I get 75% on average it is good. I have seen more than 100% during cloud lensing effect on my older panels.

One thing that needs to be kept in mind is what voltage is needed. If Masonsdad needs a higher voltage than going with several smaller watt panels in series may be a better option than one large panel.

It will be a 12v system with an mppt controller.

 

[Hedges]

Multiple smaller panels, as OffGrid said.
Shippable by UPS/FedEx rather than truck.
Less wind loading, multiple orientations for more hours of output, less cycling of battery.

Look for panels in the range of 200 W/m^2 (20% efficient) which is typical today. More power with less surface area. My older panels from years ago are about 13%.

MPPT controller requires a bit more voltage headroom. Consider required input voltage above maximum battery absorption voltage, Vmp of panel, temperature coefficient and highest anticipated panel temperature in the sun. Or just get "24V" nominal panels which will be sufficient ("12V" nominal panels might be to low), but they do tend to be larger. You could get 4x 100W (or so) panels, and wire 2s2p for 24V and two orientations.

Summer/winter hours of sun and intensity differ. You might tilt panels to maximize winter, so production similar to summer. Mounted half way up a vertical tower is a unique situation in that, unless you are far North, the sun may be behind the tower casting shade on panel during the day. In that case I think only morning and afternoon sun might hit the panels (SE and SW oriented). You might even need panel(s) facing North.

 

[OffGridForGood]

I see you note 12V but didn't say anything about the loads.
If it is just comms, perhaps low wattage generally.
I think you would be well set with 3-4 100W PV panels, and as others have said, it's easier to get these shipped since the 100W panels are smaller.
The other consideration: Where is this installation? -it's mild now, but will not stay that way - how cold will it get in winter at this transmitter site?
You will need to make a decision about battery chemistry and operating temperatures are a big part of this decision if the site gets cold.
Sealed Lead Acid or AGM may be better short term choice due to winter temps, than LiFePO4, which need to be above freezing to operate.

 

[masonsdad]

I see you note 12V but didn't say anything about the loads.
If it is just comms, perhaps low wattage generally.
I think you would be well set with 3-4 100W PV panels, and as others have said, it's easier to get these shipped since the 100W panels are smaller.
The other consideration: Where is this installation? -it's mild now, but will not stay that way - how cold will it get in winter at this transmitter site?
You will need to make a decision about battery chemistry and operating temperatures are a big part of this decision if the site gets cold.
Sealed Lead Acid or AGM may be better short term choice due to winter temps, than LiFePO4, which need to be above freezing to operate.

I'm in central Arkansas. Low wattage. I need about 200ah to get a 3 day reserve.

 

[OffGridForGood]

Central Arkansas, mild winters, but some colder days/nights possible.
If there is no heating system, then likely lead-acid or AGM will be the way to go.
There are heating pads for LiFePO4 batteries available, that can go inside an insulated box to maintain temps, but this will just add a load to your design, and unfortunately solar potential and winter are a cruel mix.

 

[masonsdad]

Central Arkansas, mild winters, but some colder days/nights possible.
If there is no heating system, then likely lead-acid or AGM will be the way to go.
There are heating pads for LiFePO4 batteries available, that can go inside an insulated box to maintain temps, but this will just add a load to your design, and unfortunately solar potential and winter are a cruel mix.

All good advice. I'm thinking lifepo4 with some small diy heaters (my son is an IT, fiber and electronics guy.) We can monitor and adjust as needed. It will be mounted in a small box on the tower, not in a shack.

 

[Hedges]

I'm in central Arkansas. Low wattage. I need about 200ah to get a 3 day reserve.

Having a 3-day reserve would mean most nights it only cycles to 15% DoD.
Lead-acid can have pretty long life with that sort of shallow cycling.
AGM is quite freeze proof fully charged, but have to check what it tolerates at the end of using 3 day reserve.
Simple is good for a small system.

Sun Xtender Solar Batteries - Photovoltaic Battery

The Sun Xtender Battery line consists of specialty lead-acid solar, photovoltaic batteries, and renewable energy storage batteries manufactured by Concorde Battery Corporation.

sunxtender.com

http://sunxtender.com/pdfs/Sun_Xtender_Battery_Technical_Manual.pdf