Solar advice for 70watt draw ?

[markus19]

Hi guys so i have joined this forum to hopefully get some advice on what i want to achieve


sooo i have some land offgrid that has no power i understand you can buy solar cctv unit with panels on and such like but i want to run hikvison power over ethernet cctv.


This will require me to run a 4 channel network video recorder and a 4g router to provide a data connection for remote viewing


the pepwave 4g router i have can power off 12dc with a max of 18watt


but the NVR is 240 and only info i can find is 10watt but that says without hard drive
so say anothr 10watts for the hard drive.


each channel uses around 6.5 watts so say 26 watts for the cctv channels


so say 64watts in total i need to be running 24/7


what sort of setup would i need to have this ?


many thanks

 

[wpns]

Depends where you are, what your average daily insolation is, and how long you want your batteries to last during cloudy days.

64 watts times 24 hours is 1.5 KWHR/day, 4 peak hours means you need 384W of panels. I would do at least 500 W of panels, 3 kWh of storage, and a 100 W inverter. But that’s just a SWAG based on not very much information.

Your power consumption numbers are kind of a guess as well, I would want to measure them before I went much further. Also measure them daytime and night time, as power consumption will vary if cameras have IR LEDs for instance.

I would also open up the NVR, and make sure there wasn’t a single (for instance) 48 V power supply in there, to run the camera POE.

 

[DIYrich]

240v to make 10 watts, Whitehaven - Are you in the UK?

10w NVR 240v
10w Drive for NVR power through NVR
18w Router including 4G 12-18w
26w CCTV power through NVR?

65 watts total. 1.5kWh per day

At a minimum, 12v system with 200ah (usable) battery for 1 day. 400ah for 3 days (off-grid, rainy days).
If you can live with an occasional black out (more than 3 days of bad weather), then that will work. Otherwise, size battery for the longest period of bad weather.

Size panels to recharge depleted battery in 1 day (for another x days of bad weather). So a 12v 400ah battery is about 5kWh. To recharge that in 5 hours of bright sunlight is 960w of production DURING THE WORST TIME OF THE YEAR. You may need 2kW of panels or more to make 1kW during the worst time of the year.

If there is no chance for freezing temps where the battery will be, then you can use LIFePO4 battery. Otherwise, Lead Acid.
For lead acid, double the ah capacity to net a usable amount (use at most 50% of the battery).

If you need an inverter to make 240v for the NVR, then find out the power requirements for the inverter. It could be the inverter itself may need 30w or more, and there is some conversion losses in DC watts from battery to AC watts. So, you may need to double the system size.

If the NVR can take 20v or 48v, then build a 24v or 48v system, and get a power converter to step down from battery voltage to 12v. That will be more efficient than DC->AC->NVR. Stepping down from 24v to 48v is easier than stepping up. However, if you will need Lead Acid batteries, then stepping up from 12v to 24v or 48v is not that bad. I would rather have 12v lead acid batteries in parallel (12v system) and step up the power to 24 or 48v than running them in series to make the higher voltage and stepping down to 12v. If one battery goes bad, then you can take it out and run on reduced capacity.

If the area gets snow, consider vertical ground mount of the panels.

 

[chrisski]

Recommend you use a solar calculator like in my signature block, that way you can change the numbers.

For a place like the UK where weather can be cloudy, I would not be surprised if you need much more than 2 kWh of panels to meet a 1.5 kWh demand. The calculator takes in weather and will help.

Part of this math will include how many days you want this to run for bad weather, and also if this is grid connected, and if off grid, can you fix this if the batteries shut off.

Without looking at the data, I may want a ~6 kWh battery pack to account for 4 days of runtime with no charging for a totally off grid situation.

Also in my signature block is a link to a post where there is talks about sizing for a system in a good area for solar like where I live, and a not so good area for solar like the UK. Huge difference in requirements.

 

[kommando]

About 70 miles north of Whitehaven I use a 250w panel and 90ah 12v battery to power a 25w CCTV camera and WiFi. Need to charge the battery once or twice during the Dec/Jan period each year dependant on number of cloudy days in succession. So you would need 700w of panels plus a bigger battery. 250w panels 2nd hand are £30 ea locally.

 

[Hogheavenfarm]

75w is about the draw on my current system, which handles that quite well up to 3 days. I have about 2kw of panels and 9600wh of batteries (4 X 200ah, AGM) using a 24v system. I run 3 chest freezers, and since they run intermittently, 75w is the average reading.

 

[markus19]

Hi guys thanks so much
for your very in depth replies im trying to take it all in whats been said lol.


im in whitehaven in cumbria so the weather is often poor... for sure during the winter months..


ive just checked the nvr spec and it does run 48vDC


also i have 4x 6v deep cell 235ah batteries that came off a golf club car can i make use of these in the system

 

[MTM98290]

https://a.co/d/hoxAKv6

If you aren't set on dvr/poe cameras these have their own battery and solar panel. They are self sustaining if you mount the solar panel in a reasonable place. I know that these are totally different, but using this style of camera allows use much smaller system.

We run them off grid near 48° lattitude and they work great. We only need to provide 10-15w an hour to keep a connection.

It looks as though if you don't need NVR then you should be able to run it without any inverter.

12v x 18w 216watts per 24 hours for the example of the 4g router.

 

[Hogheavenfarm]

I have one like that, and it does work well, although controls are limited by the app, but it does what I need. It will still need to connect to a router of some type for remote applications.

 

[MTM98290]

I have one like that, and it does work well, although controls are limited by the app, but it does what I need. It will still need to connect to a router of some type for remote applications.

They work well for the price. I doubt that they are as nice as the o.p.'s camera setup, but they are no load at all on the battery bank.

Yes you need a router, many are 12v dc. We use a 5v usb micro powered router that consumes 1-2w.