Special - Isle system: Min. power supply, snapshot mode,...

[Oakld 0]

Hello all,

 

I can use advices on this topic, since I have little experience with CCTV and I don't even trust local shops to be able to supply what I need.

 

I need to optimize camera system in terms of minimum power supply, remote data saving and related to both previous points is optimized mode of operation. Last but not least, cost is also a parameter.

 

Requirements:

• Isle operation - it will be installed on a remote objects with no electrical supply. The system will be powered by 12V DC acumulators (this is standard power supply of both cameras and control units) with assistance of solar "isle system" recharging. Especially from October till March the solar won't supply enough power and accumulators will have to be manually recharged by generator. So minimizing number of components and selecting an optimal mode of operation of cameras, especially in regard of IR LED lighting is a key to success
  
• Optimally 6 cameras with IR LED - the object is in open area accessible from all sides, we need 1 camera inside to keep eye on horses, this leaves 5 cameras for the outside, depending on angle view bearly covering the surroundings. If we use only 4 cameras, we'll have to add dummies to black spots.
  
• Snapshot mode of operation - to save power and internet traffic, best preferred method of operation seems to be a snapshot mode. Let's say, that in quiet mode, every 10 seconds a camera would do a snapshot and would stay turned off between the snapshots. A serious crack to this idea was a claim of a friend, that most cameras cannot turn of the IR (it's always on) and if you turn them on and off, it takes some time to focus them. So I'd really appreciate clarification how they behave and what's possible to achieve.
  
• Saving data - the data should be saved on the internet (i.e. FTP server, Dropbox, Google Disk, etc.). No monitor, mouse or keyboard will be on-site, setting and adjusting to be done over the internet (Linux and/or Windows and/or Android). Ideally, in case of detected potential threat, a more frequent snapshotting or continous recording should be engaged. In such cases, an alert in form of facebook message, google hangouts message or email or such would be a nice feature. The system will be connected to wireless internet connection with 500Kbps upload speed installed just for this purpose. Optionally saving to local medium as well, preferring an SD card over HD (due to power requirements)
  
• optionally, a connection to a motion sensors or complete small alarm system

 

If I consider a system such as Evolveo Detective (http://www.evolveo.eu/en/detective_s4cih7d), then I believe the issues are:

• excessive components and features - higher power demand than required by what I need
  
• mode of operation - probably, supplied software won't allow to tune the system (cameras and data uploading) to a configuration with minimum power demands

 

Another idea would be a small Linux router with scripts run by the router to turn on the cameras and save the snapshots over the internet.

 

Of course, the best would be to point out to product, which is "off-shelve" and has low power demands.

 

Thanks in advance for any useful suggestions.

 

Regards,

 

Oak

[SyconsciousAu 0]

 

Thanks in advance for any useful suggestions.

 

Regards,

 

Oak

 

You wont find an off the shelf system that will do that. Where is this system being installed that you cant get enough solar to power it?

 

You can get cameras with on board storage that draw less than 6 watts. Even with routers and switches your draw should be under 75 watts at worst.

 

Also have you costed your data?

[Oakld 0]

Hello,

 

technically speaking, yes, it is possible to harvest and store enough energy even for those cameras. But let's be realistic and assess a feasible system.

 

Sorry for any mistakes bellow, I'm not an electrician. I'd be pleased to be corrected.

 

Considering a feasible 200Wp panel (at cca 230 USD), it will do per day roughly 2Wh per Wp, which is 400 Wh per day (in central Europe, cca 120km north from Wiena). But this is going to be far less in winter months, roughly 160 to 180 Wh.

Now this power has to be stored. Ordinary lead batteries, even those which claim to be "solar" are rubbish, as you cannot use more then 20% of the capacity, or you will destroy them very soon. So I consider a LiFePo4/LiFePoY4 batteries - more expensive, but excellent in draining and recharging. So 4 battery cells 3.2V, 40Ah @ 80USD will make a battery of 12.8V 160Ah at cost of 400USD (incl. balance unit). Let's consider an 80% efficiency, so we have 160 Ah * 12V * 0.8 = 1536 Wh a day. BTW I consider putting it into a plastic tube circa 1m bellow surface level to keep it in frost-free depth.

 

Now, let's calculate the security system. Each camera with IR on (typically) needs 260mA power. In winter months, it will require 14hrs on (6pm to 8 am), so it's 0.26A * 12V = 3.12W a day per camera. If all 5 cameras would be on all the time, it's roughly 16W. Let's estimate the day operation to 4W for all cameras. So we need 14hrs * 16W + 10hrs * 4W = 296Wh. The recorder needs 3W power supply, so let's estimate it's power requirement to 1.5W --> 24hrs * 1.5W = 36Wh. Another roughly 3W will require internet modem with wireless antena --> 24hrs * 3W = 72Wh.

Plus let's consider 4hrs of LED lights on @ 20W = 80 Wh

In total it's 296 + 36 + 72 + 80 = 484Wh. So it's far less then stored energy and the difference should even accommodate some losses due to efficiency, and even more cameras can be added.

 

Actually, this looks feasible, which I am surprised of. The calculations didn't work for me previously, because I considered lead batteries and far more consuming cameras (5W per camera + 2W per IR LED light), but here http://www.evolveo.eu/en/detective_s4cih7d (at the very bottom line) they state that the cameras have 260mA with IR LED on. So the selection of cameras will affect the system a lot, I suppose. And providing that I didn't make any cardinal mistake in calculations. There might be need for additional efficiency ratios, for instance.

To complete costs for anyone interested: WiFi antena and modem one-time cost is 53 USD, monthly charge is 8.25 USD (a special offer for low download speed, but 500Kbps upload speed).

 

Can someone say, whether my calculations are correct?

Any practical experience?

 

Regards,

 

Oak

[SyconsciousAu 0]

Hello,

 

technically speaking, yes, it is possible to harvest and store enough energy even for those cameras. But let's be realistic and assess a feasible system.

 

Everything is feasible, with the right budget

 

 

Considering a feasible 200Wp panel (at cca 230 USD), it will do per day roughly 2Wh per Wp, which is 400 Wh per day (in central Europe, cca 120km north from Wiena).

 

That's about 52 degrees north lattitude. That's a tough ask for solar.

 

Have a look at

 

http://www.pveducation.org/ and http://www.builditsolar.com

 

For some useful info and links on solar.

 

But this is going to be far less in winter months, roughly 160 to 180 Wh.

 

You have a tough site but you should be able to get more than that out of each panel in winter. Assuming that they are unshaded and pointed due south and orientated correctly.

 

You will want to think about a solar panel mount with moveable azimuth. At that latitude the sun only makes it up to 15 degrees or so during the day so your panels won't be far off vertical in winter. On the plus side any snow will fall right off. In summer they will need to be a lot flatter

 

 

Now this power has to be stored. Ordinary lead batteries, even those which claim to be "solar" are rubbish, as you cannot use more then 20% of the capacity, or you will destroy them very soon. So I consider a LiFePo4/LiFePoY4 batteries - more expensive, but excellent in draining and recharging. So 4 battery cells 3.2V, 40Ah @ 80USD will make a battery of 12.8V 160Ah at cost of 400USD (incl. balance unit). Let's consider an 80% efficiency, so we have 160 Ah * 12V * 0.8 = 1536 Wh a day. BTW I consider putting it into a plastic tube circa 1m bellow surface level to keep it in frost-free depth.

 

The other option is nickel iron batteries.

 

Now, let's calculate the security system. Each camera with IR on (typically) needs 260mA power. In winter months, it will require 14hrs on (6pm to 8 am), so it's 0.26A * 12V = 3.12W a day per camera. If all 5 cameras would be on all the time, it's roughly 16W. Let's estimate the day operation to 4W for all cameras. So we need 14hrs * 16W + 10hrs * 4W = 296Wh. The recorder needs 3W power supply, so let's estimate it's power requirement to 1.5W --> 24hrs * 1.5W = 36Wh. Another roughly 3W will require internet modem with wireless antena --> 24hrs * 3W = 72Wh.

Plus let's consider 4hrs of LED lights on @ 20W = 80 Wh

In total it's 296 + 36 + 72 + 80 = 484Wh. So it's far less then stored energy and the difference should even accommodate some losses due to efficiency, and even more cameras can be added.

 

.26A is 3.12 watts per hour per camera, not per day.

 

The number one mistake people make is underestimating their current draw. I think 3 to 4 amps (36 to 48 Watts) is a realistic figure for the setup you are contemplating. That's 72 - 96 Amp Hours per day.

 

The next question you need to ask is how many sunny days you get because your solar generation is next to zero on cloudy days. Shading a panel massively reduces their output.

 

Say for example you are expecting two cloudy days between each sunny day you need to factor that in, both in your battery and generation capacity.

 

So in that three days you are going to use 388 amp hours. If you are using lead acid and want to limit your depth of discharge to 20% you will need 1940 Amp Hours of battery capacity. That also means that if you get a bad week you can have a week without sun and still be at less than 50% depth of discharge

 

You can then size your solar array. If you want to recharge all of that consumed power in a single sunny day then you are going to need 4656 watts on that sunny day. If you get two hours worth of generation from your panels at the site you will need a 2.5kw array.

 

The more sunny days you get between cloudy ones the smaller your array can be but remember you need some reserve capacity in your array to get the battery back up after a bad couple of days.

 

Either way the array you are looking at is going to be significantly bigger than the 200 watt panel you were considering, as will your battery pack.

 

What you may want to consider is doing a wind survey at your site. A wind generator may be a more viable option than a large solar array. A small solar array combined with a wind generator may also work for you if you have windy winters and still summers.

[Oakld 0]

Hello,

 

I got an interesting link to calculation software online, here are the results:

 

PVGIS estimates of solar electricity generation

 

Solar radiation database used: PVGIS-CMSAF

 

Nominal power of the PV system: 0.2 kW (crystalline silicon)

Estimated losses due to temperature and low irradiance: 8.1% (using local ambient temperature)

Estimated loss due to angular reflectance effects: 2.9%

Other losses (cables, inverter etc.): 14.0%

Combined PV system losses: 23.3%

 

Fixed system: inclination=34°, orientation=0°

Month Ed Em Hd Hm

Jan 0.18 5.68 1.11 34.3

Feb 0.35 9.70 2.09 58.5

Mar 0.61 18.9 3.78 117

Apr 0.81 24.2 5.23 157

May 0.79 24.5 5.28 164

Jun 0.81 24.2 5.45 163

Jul 0.81 24.9 5.51 171

Aug 0.77 23.8 5.20 161

Sep 0.62 18.6 4.06 122

Oct 0.43 13.3 2.70 83.8

Nov 0.21 6.42 1.32 39.7

Dec 0.14 4.28 0.85 26.2

Yearly average 0.543 16.5 3.55 108

Total for year 198 1300

 

Ed: Average daily electricity production from the given system (kWh)

Em: Average monthly electricity production from the given system (kWh)

Hd: Average daily sum of global irradiation per square meter received by the modules of the given system (kWh/m2)

Hm: Average sum of global irradiation per square meter received by the modules of the given system (kWh/m2)

So the previous calculation was about correct, the worst is actually December with poor 140 Wh a day.

 

As for batteries, I made a mistake in calculation. One cannot add capacities of particular cells when they are connected in series. Correct capacity is then only 40 Ah * 12V * 0.8 = 384 Wh a day.

 

The other option is nickel iron batteries.

Unfortunately I found none in the "local" internet shops sells NiFe batteries, so far...

 

.26A is 3.12 watts per hour per camera, not per day.

OK, I double checked the electrical work formulae: W [Wh] = U [V] * I [A] * t [hrs] = 12V * 0.26A * 24 hrs = 74.88 Wh. So you are right and that means that really, there's far not enough energy to power all the cameras, actually not even one half the night.

 

I can actually state, that I have 1.3 A available in battery capacity for everything together (for 24hrs operation), which is terribly small current. It's not even enough to run the Athena and modem.

 

As for wind generation, it was advised by my internet supplier, who does those installations for companies in water business (probes etc) in remote isolated areas. But really, it doesn't seem to be feasible here. There's very little wind available and to get some meaningful output from the wind generator, you need quite strong wind. A good generators start supply energy at very low wind speeds, however only fraction of their full power.

 

So really, I'll have to optimize on all fronts. Possibly a completely geek setup will be required with linux PDA/phone type of controller (instead of recorder) and controlled cameras switching on/off?

If I fail to create a feasible camera setup, I will have to consider a combination of a perimeter control (alarm with GSM connection rather then internet) and camera traps.

 

BTW, does the CMOS chip in the camera need to be heated in winter by it's own continuous operation?

 

Sad thing is, that I DO have to expect intruders .

 

Thank you all for your comments!

 

Regards

 

Oak

[tomcctv 187]

Hi. Mobotix cameras are going to be best for your application

 

Ideal for solar power ..... What is your budget

[zr1 0]

While it's not a direct comparison...

 

I run security cameras at construction sites on solar/battery power...

* 4 cams (1 is a PTZ)

* motion sensors

* motion lights (LED arrays)

* some flashing warning lights (gotta keep the vandals away at night)

* battery charging hardware

* DVR/NVR

* router (on a cell connection)

 

Running 3 large (150lb) batts (I think 200AH each, I'd have to look...but not those rubbish $359 200AH batts on Amazon), it'll make it through the night fine. But give it a couple of cloudy days...and it'll go to sleep on the 3rd or 4th night. It'll wake back up the next sunny morning though.

 

Oh..and this is in Arizona...so lotsa sunshine.

 

It's doable.

Just pricey.

And heavy.

[ilk 0]

While it's not a direct comparison...

 

I run security cameras at construction sites on solar/battery power...

* 4 cams (1 is a PTZ)

* motion sensors

* motion lights (LED arrays)

* some flashing warning lights (gotta keep the vandals away at night)

* battery charging hardware

* DVR/NVR

* router (on a cell connection)

 

Running 3 large (150lb) batts (I think 200AH each, I'd have to look...but not those rubbish $359 200AH batts on Amazon), it'll make it through the night fine. But give it a couple of cloudy days...and it'll go to sleep on the 3rd or 4th night. It'll wake back up the next sunny morning though.

 

Oh..and this is in Arizona...so lotsa sunshine.

 

It's doable.

Just pricey.

And heavy.

 

This might help http://www.renewablemotion.co.uk/deployable.html

 

Regards

 

Ilkie