Simple, solar powered remote camera setup

[gabor]

Hello guys,
first of all, I'm new in solar powered systems. I tried to research a lot, and before I purchase the parts, I would like to ask the pros

I'm thinking on a very simple setup for a remote camera system. I would like to a Tycoon Power TP-Scope-1224 charge controller, Ubnt NanoBeam NBE-M5-19 5Ghz wifi AP, and a Hikvision DS-2CD2032-I Network Camera. Total consumption is only about 15W.
I would like to use the station ONLY daytime, night time it can be off.
For the power supply, I'm thinking to use Monocrystalline Solar Panel 100W + 12V 17A deep cycle lead-acid battery.

The solar panel: http://world.taobao.com/item/5202499....KgAEAh#detail

My question is: do you think this system could work in a full cloud covered day or even in fog? Is this panel is big enough to produce stable power supply even in weak conditions?

Thank you!

[PNjunction]

Total consumption is only about 15W.

That would work. I would assume that it is 15W -per hour-, and you are basing it on a sticker rating. A measured rating might actually be less. I'm also assuming you are using an inverter, and as such get one that is high efficiency and a PSW or pure-sine-wave inverter. Samlex inverters do very well. Get a small one, and not a large one to keep efficiency up and turn it OFF when not in use.

For the power supply, I'm thinking to use Monocrystalline Solar Panel 100W + 12V 17A deep cycle lead-acid battery.

A 17A little agm battery (again assuming agm which is typical) will only withstand 0.3C continuous current before developing hot spots. If your panel is *perfect* or actually is under-spec'ed a little, I'd use a slightly larger battery. Shown in the add is a description for 100w, yet the pic shows 150w.

Instead of being on the edge, use a 22-26ah battery. Do NOT use GEL. Be sure to set your charge controller properly for 14.4-14.8v absorb.

My question is: do you think this system could work in a full cloud covered day or even in fog? Is this panel is big enough to produce stable power supply even in weak conditions?

No panel does well under these conditions. For instance, when you just barely start to see shadows, your panel is operating somewhere near 1/10th the current output. So instead of 5.5A under best conditions, that would drop to about 500ma in *bright* fog.

Under these conditions, and with a 17ah battery, you'll only get about 6 hours of operation (in the dark) before you need to pull the switch to stop the battery from discharging below 50% DOD, or half-charge if you want any sort of life out of it. Daytime, you should have no problem.

Use a slightly larger battery, and under less than ideal conditions, it will still have half a chance to get some sort of charge.

Ideally you'll want to know your solar-insolation-hours (different from just sunrise-to-sunset), but from this distance, this is about the best we can do winging it, unless you really want to spend a lot of $$$.

[bcroe]

I'm thinking on a very simple setup for a remote camera system. I would like to a Tycoon Power TP-Scope-1224 charge controller, Ubnt NanoBeam NBE-M5-19 5Ghz wifi AP, and a Hikvision DS-2CD2032-I Network Camera. Total consumption is only about 15W.
I would like to use the station ONLY daytime, night time it can be off.
For the power supply, I'm thinking to use Monocrystalline Solar Panel 100W + 12V 17A deep cycle lead-acid battery.

The solar panel: http://world.taobao.com/item/5202499....KgAEAh#detail
My question is: do you think this system could work in a full cloud covered day or even in fog? Is this panel is big enough to produce stable power supply even in weak conditions?

I suppose the equipment can be directly powered by 12VDC? My own approach would be to use a rather
large but economical grid tie panel (300W) that would be able to produce the 15W even under most clouds.
No charge controller or troublesome battery, just a 1.5A DC - DC converter set for 12V output. Bruce Roe

[gabor]

Yes, no inverter planned, they will get the power directly from the charge controller. The UBNT AP needs 24V Power over Ethernet, and the camera needs 12V. That's why I choose that charge controller:

--
Tycon Power Systems POE/Solar charge controllers have dual inputs to charge batteries from a POE source and also a secondary source like solar panels in order to provide redundancy and insure 100% uptime for critical applications. The solar input can handle up to 8A. The POE input up to 2.5A. They have a built in POE inserter that delivers 24V 1.25A at the POE out port. They also have a secondary wire terminal 12V 1.5A output. They have full electronic protections for short circuit, reverse current, overvoltage, overcharge and over discharge.
--

300W panels are needs lots of space, and we would like to mount it to the top of the pole. And I think the controller won't handle 300W, specifiactions are here: http://tyconpower.com/products/files...Spec_Sheet.pdf
It seems to me, I should get a bigger battery and a timer switch which turns everything off at night? What do you think about this option?

Thank you everyone!!!

[PNjunction]

Yes, no inverter planned, they will get the power directly from the charge controller.

Your system needs *stable* power, and a charge controller without a battery certainly is not that. A common newbie mistake is trying to measure the output of a controller without a battery, and then assuming the charge controller is faulty when they see no output.

Trying to run a controller without a battery is one of the first things that many newcomers do to try and outsmart the manufacturers. It won't work - but for an educational experience, go ahead and try it.

Charge controllers are designed specifically to have a battery attached, not attached directly to an electronic load. Electronic loads are attached to the battery itself. You attach the battery to the charge controller first, and the panel last.

Stick to your original plan of the 17ah+ battery.

[SunEagle]

Your system needs *stable* power, and a charge controller without a battery certainly is not that. A common newbie mistake is trying to measure the output of a controller without a battery, and then assuming the charge controller is faulty when they see no output. Trying to run a controller without a battery is one of the first things that many newcomers do to try and outsmart the manufacturers. It won't work - but for an educational experience, go ahead and try it. Charge controllers are designed specifically to have a battery attached, not attached directly to an electronic load. Electronic loads are attached to the battery itself. You attach the battery to the charge controller first, and the panel last. Stick to your original plan of the 17ah+ battery.

If you look at the spec sheet for that Tycon unit it allows you to wire a solar panel and battery directly to it which then allows you to power a camera. It looks like it charges the battery and changes the panel DC voltage to the 12v that the camera uses. Looks like a pretty neat little device.

[bcroe]

Yes, no inverter planned, they will get the power directly from the charge controller. The UBNT AP needs 24V Power over Ethernet, and the camera needs 12V. That's why I choose that charge controller:

Tycon Power Systems POE/Solar charge controllers have dual inputs to charge batteries from a POE source and also a secondary source like solar panels in order to provide redundancy and insure 100% uptime for critical applications. The solar input can handle up to 8A. The POE input up to 2.5A. They have a built in POE inserter that delivers 24V 1.25A at the POE out port. They also have a secondary wire terminal 12V 1.5A output. They have full electronic protections for short circuit, reverse current, overvoltage, overcharge and over discharge.

300W panels are needs lots of space, and we would like to mount it to the top of the pole. And I think the controller won't handle 300W, specifiactions are here: http://tyconpower.com/products/files...Spec_Sheet.pdf
It seems to me, I should get a bigger battery and a timer switch which turns everything off at night? What do you think about this option?

You didn't give a location, so we can't guess your weather or insolation. The exact power .
needed by the system needs to be determined.

If you use a battery, you have added a relatively high maintenance item to the system, and
the charge controller will be much more expensive than a simple converter or 2. You will
need to turn the equipment on and off; a photocell detector would do it. A timer would
need frequent resetting, to track the seasons and any disturbance that comes along.

Eventually a long stretch of bad weather will flatten the battery; perhaps a battery that
won't be damaged by that could be used. What's in those solar garden lights that only
last a few hours each night?

An oversized panel without battery will probably manage to remain operational indefinitely.
Even if it gets covered with snow and drops out, no damage will be done without a battery.
On-Off is automatic. Bruce Roe

[gabor]

Okey, thank you very much your comments, they makes sense. The location is Dali, Yunnan, China. I would say 3-4 sunny hours a day average, usually cloudy in the afternoon.

[gabor]

Hi Bruce, can you show me this DC converters please? They convert from any Voltage what the solar panel produces to stable 12V and 24V? I can't find them...
I just connect the DC converters input to the solar, and the output to my devices? Sounds very easy and simple! I can make this happen with a 250 or 300W panel, let's see how is it works, and later even can upgrade to a solar controller + battery version, i think!
Thanks!

You didn't give a location, so we can't guess your weather or insolation. The exact power .
needed by the system needs to be determined.

If you use a battery, you have added a relatively high maintenance item to the system, and
the charge controller will be much more expensive than a simple converter or 2. You will
need to turn the equipment on and off; a photocell detector would do it. A timer would
need frequent resetting, to track the seasons and any disturbance that comes along.

Eventually a long stretch of bad weather will flatten the battery; perhaps a battery that
won't be damaged by that could be used. What's in those solar garden lights that only
last a few hours each night?

An oversized panel without battery will probably manage to remain operational indefinitely.
Even if it gets covered with snow and drops out, no damage will be done without a battery.
On-Off is automatic. Bruce Roe

[bcroe]

Generating low power under clouds

Hi Bruce, can you show me this DC converters please? They convert from
any Voltage what the solar panel produces to stable 12V and 24V? I can't find them...
I just connect the DC converters input to the solar, and the output to my devices? Sounds very easy and simple! I can make this happen with a 250 or 300W panel, let's see how is it works, and later even can upgrade to a solar controller + battery version, i think!

Take a look at DC - DC converters on Eb*y, for example this 2A adjustable output voltage item number
161476280982 There are plenty of versions of this very efficient buck converter available. I would
operate them at less than half the rated current for reliability; check your input and output current &
voltage ratings against the job.

A 250W panel is probably the best W/$ deal and perhaps a closer voltage match, check your exact
equipment power requirements.

If you need 2 voltages, check if the power rail is connected to system ground. The buck converters I
mentioned have a common negative terminal for input and output power, so 2 of them would have
the negatives tied together. If your equipment can't work that way, at least one of the converters
will need to have an isolated set of output leads; these are more expensive and somewhat less
efficient. This would also be true of a battery system. good luck, Bruce Roe

[gabor]

Hi Bruce, sorry, but I don't understand the issue with system ground. I attached a wiring plan, did you mean like that?
Yes, I need 2 voltages, and I don't know if my devices requires isolated leads or not, but if yes, what should I buy instead of the LM2596?

I read, this DC DC converterts needs minimum same+1,5V input voltage as output voltage. What if there is very less sun power, the panel will always provide enough voltage?

Thank you your comments, they are very helpful for me.

Take a look at DC - DC converters on Eb*y, for example this 2A adjustable output voltage item number
161476280982 There are plenty of versions of this very efficient buck converter available. I would
operate them at less than half the rated current for reliability; check your input and output current &
voltage ratings against the job.

A 250W panel is probably the best W/$ deal and perhaps a closer voltage match, check your exact
equipment power requirements.

If you need 2 voltages, check if the power rail is connected to system ground. The buck converters I
mentioned have a common negative terminal for input and output power, so 2 of them would have
the negatives tied together. If your equipment can't work that way, at least one of the converters
will need to have an isolated set of output leads; these are more expensive and somewhat less
efficient. This would also be true of a battery system. good luck, Bruce Roe

[bcroe]

Hi Bruce, sorry, but I don't understand the issue with system ground. I attached a wiring plan, did you mean like that?
Yes, I need 2 voltages, and I don't know if my devices requires isolated leads or not, but if yes, what should I buy instead of the LM2596?

I read, this DC DC converterts needs minimum same+1,5V input voltage as output voltage. What if there
is very less sun power, the panel will always provide enough voltage?

First, you originally said the system would only need 15W. 24V X 0.8A = 19.2W, 12V X 0.5A = 6W,
total 25.2W. If we increase that by 10% for converter losses, its 27.7W. So the panel would need
to deliver 10.7% of max rating, probably still OK. I would measure the real numbers which might
turn out to be a lot less.

The buck converter needs an input V at least 1.5V higher than the output V. Since your panel
has a Vmp of 31.2V, you are good. Turns out Vmp and Voc don't vary much with sun, but the
available current is about proportional. In operation the converters would take the current they
need while operating between Voc and Vmp. When the available sun can no longer supply the
needed 28W, PV voltage will drop below Vmp and the system will cease to supply needed
load power.

Note that your panel Voc is 38.5V. That may for 25 deg C. If you get a lot cooler, the Voc
will rise in a predictable way, probably over 40V. You need to be assured, that the converter
max input V is never exceeded by Voc.

Your drawing doesn't show everything, there is a signal cable from the camera to the radio.
I doubt its an isolated differential cable; more likely a coax cable. If the coax shield were
connected to the negative power lead on both units, you are good. If its connected to an
intermediate voltage,, your power will be trying to short out through this path. Maybe the
simplest method is to just use an isolated output (not buck) supply for the camera.

An isolated converter would be like Eb*y 391099150347, 12V 5W output out. I suspect
that is enough, though you had listed 6W. Since the input V range of this is a bit limited, it
could be powered by the output of the 24V supply. It might take more research to find a
perfect match; there are a lot more converters putting out isolated 5VDC. Maybe your
camera would be happy with the output of 2 of these seriesed for 10V. Bruce Roe

[gabor]

Yes, I made a mistake in the very beginning with the calculations, thanks. Thank you for the detailed help, I will go trough this isolated converters. I will let you know, once I'm done, how is it works, if you are interested
Thanks,
Gabor

First, you originally said the system would only need 15W. 24V X 0.8A = 19.2W, 12V X 0.5A = 6W,
total 25.2W. If we increase that by 10% for converter losses, its 27.7W. So the panel would need
to deliver 10.7% of max rating, probably still OK. I would measure the real numbers which might
turn out to be a lot less.

The buck converter needs an input V at least 1.5V higher than the output V. Since your panel
has a Vmp of 31.2V, you are good. Turns out Vmp and Voc don't vary much with sun, but the
available current is about proportional. In operation the converters would take the current they
need while operating between Voc and Vmp. When the available sun can no longer supply the
needed 28W, PV voltage will drop below Vmp and the system will cease to supply needed
load power.

Note that your panel Voc is 38.5V. That may for 25 deg C. If you get a lot cooler, the Voc
will rise in a predictable way, probably over 40V. You need to be assured, that the converter
max input V is never exceeded by Voc.

Your drawing doesn't show everything, there is a signal cable from the camera to the radio.
I doubt its an isolated differential cable; more likely a coax cable. If the coax shield were
connected to the negative power lead on both units, you are good. If its connected to an
intermediate voltage,, your power will be trying to short out through this path. Maybe the
simplest method is to just use an isolated output (not buck) supply for the camera.

An isolated converter would be like Eb*y 391099150347, 12V 5W output out. I suspect
that is enough, though you had listed 6W. Since the input V range of this is a bit limited, it
could be powered by the output of the 24V supply. It might take more research to find a
perfect match; there are a lot more converters putting out isolated 5VDC. Maybe your
camera would be happy with the output of 2 of these seriesed for 10V. Bruce Roe