Going over to solar for lighting/security

supersunbird

supersunbird

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So I want to go over to solar for running my lighting and security devices (electric fence, gate motor, outside lighting) and recharge phones and tablets at 1 point close to DB.

I have calculated the load to be 1250W if ALL lights (don't see that happening) and devices are on.

Are my calculations correct in that it will be 5,6 Amps load and thus use 67.2ah for a 12 hour load period.

So what would I need?

- 1 x 120ah lead crystal battery?
- 5 x 250w solar panels?
- 10A solar regulator?
- 1500W inverter?

I want to be totally of the grid regarding overhead lighting and security.
 
Some quick feedback.
Your battery is undersized as you need to allow for the lower voltage I.e. either 2v cells or 12v battery..
Also panels don't run at full efficiency the whole day. Work with 6-7 hours sunlight and around 80-90% efficiency for cable loss/ converting voltage.... Also batteries shouldn't be discharged by more than 30-40% to get them to last.
Hope that helps
 
How many more batteries? and lead crystal doesn't mind being discharged a lot.

MY 1250W load is unlikely, it will probably be under 800W or even 600W most times.
 
1200watt continuous drain at 12v is 100A. I guess you calculated it at 220v but your supply is 12v if you only have 1 12v battery so that is what you should be using.

So if you are drawing 50% of your max on average:
100AX12hx50% = 600Ah needed.

So I would get 12 100Ah deep cycle batteries (you should not drain them more than 50% so they have 50Ah of useable storage)
 
atomcrusher said:
I thought that was a brand, and that you were recommending MOAR Batteries, so I looked "Moar" up:o. I'll stick to my Deltec bateries :twisted:
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Haha. Sorry if I caused confusion.

15 or 20 100A-hr batteries in parallel should do the trick, especially in times where there is limited sunlight (extended daytime thunder showers etc.).

I'm personally a fan of Lead/Calcium or Iron/Nickel batteries. If you can get your paws on some Nickel/Zinc, then that is an awesome type to use for solar application. Very high energy density and no nasty chemicals.
 
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supersunbird said:
Ah yes, knew there was a flaw in my calculations. Always sucked at the physics :(
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Dont worry I screw up simple things all the time never mind doing math and remembering formulas. The only reason I know the calculations is that I am trying to do the same as you but its damn expensive even if you just want to do the lighting and the odd plug.
 
http://www.bushpower.co.za/products.asp?pc=46

BENEFITS
•RECYCLABLE Up to circa 99% - and far fewer batteries need be produced/used.
•GREENER No dangerous acid mist or harmful gas emissions. Non-corrosive. Significantly less pollution. ISO 14001 certified.
•SAFER No toxic fluid. No hazardous emissions. No risk of explosion.
•EASY TRANSPORT Classified as non-hazardous for transportation. The only battery allowed for air-freight as normal goods.
•GUARANTEED QUALITY Each battery comes with a standard 3 year factory guarantee - ISO 9001 certified.
•BETTER USAGE PERFORMANCE Charges 20% - 40% faster than conventional alternatives. Excellent high current discharge ability.
•FULL RECOVERY Can be 100% discharged and then restored to full-rated capacity daily, with no risk to battery life.
•LONG BATTERY LIFE Service life of 18-20 years at 25°C. Up to 3,100 charge/discharge cycles.
•LONG SHELF LIFE Can be stored for 2 years with no additional charging. Simplifies Logistics.
•EXTREME TEMPERATURE RESISTANCE Operates at temperatures from -40°C to +65°C
Click to expand...

I'll just use the more expensive batteries, and as I said the 1250W is peak load and will hardly ever happen any night, most nights would be under 800w at peak and most of the night just 200W as outside security lights.
 
Beachless said:
Dont worry I screw up simple things all the time never mind doing math and remembering formulas. The only reason I know the calculations is that I am trying to do the same as you but its damn expensive even if you just want to do the lighting and the odd plug.
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We had a 5 day outage (cut on wednesday, reconnected Monday after noon) in Sept due to billing issue. If I just had proper lights and working security it would have been much more bearable.

And even if you do pay you get cut off (load shedding) and who know how bad it might get in the future...
 
supersunbird said:
We had a 5 day outage (cut on wednesday, reconnected Monday after noon) in Sept due to billing issue. If I just had proper lights and working security it would have been much more bearable.

And even if you do pay you get cut off (load shedding) and who know how bad it might get in the future...
Click to expand...

By us they stole the power cables twice in three months to go along with the load shedding the one was 3 days downtime and the other one just over a day.

I will probably end up doing the the main bedroom for:
2 CFL 15W bedside lamps
TV(100W)
microserver(100W)

The kitchen, bathrooms all have downlighers which I will convert to LED and will then only use 40W
Internet routers, swithes, alarms,Decoders etc(100W)
Solar geyser

So that way I can get away with under 500W max and still have most of my conveniences.


Water is also on my list of things to do and is probably more important .
 
Beachless said:
By us they stole the power cables twice in three months to go along with the load shedding the one was 3 days downtime and the other one just over a day.

I will probably end up doing the the main bedroom for:
2 CFL 15W bedside lamps
TV(100W)
microserver(100W)

The kitchen, bathrooms all have downlighers which I will convert to LED and will then only use 40W
Internet routers, swithes, alarms,Decoders etc(100W)
Solar geyser

So that way I can get away with under 500W max and still have most of my conveniences.


Water is also on my list of things to do and is probably more important .
Click to expand...

A similar setup as above should do the trick.

For the solar pannels, you should be paying around R11 per watt. About 1.5kW in panels should do the trick, assuming 4 hours a day average of usable sunlight that'll get you about 6kW.hr.

A 12 V 100Amp.hr battery is equivalent to 1.2kW.hr. (P = V*I ; P.hr = V*I.hr), so you need about 5 deep cycle batteries (if you can get your paws on a Nickel/Zinc - they're not too common yet), but if you get a lead-type, you'll only want to drain to about 50% to extend life of battery, so you'll need about 10 100A.hr batteries.

6kW.hr should give you 12 hours of usefulness.

As for OP, you need 10 batteries at least. If you go the lead/crystal route, then you'll need about 20 100A.hr battereies.
 
Also, how can your microserver be using 100W????

For the love of electrons man, get a Pi and external hard-drive bay setup. My one averages 8W and maxes out at 40W.
 
Also, allow around 15-20% loss in transmission and inversion. You might get away with 8-10% in practice, but build in some margin as the cost increment is insignificant.

Make sure your MPPT/regulator and DC cabling can handle 30-40% more amps than the pv panel nominal rating. The edge-of-cloud effect can spike current production rather dramatically, and you don't want this to overwhelm your DC circuits and cause a fire.

Lastly, remember to run a Cat6 cable while you're cabling in the panels. This will allow you to add a cam and sensors to keep an eye on things, including panels, which have been known to grow legs.

(I run a 12kW array on 48V into a 12kW inverter and 24 batteries.)
 
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agentrfr said:
Also, how can your microserver be using 100W????

For the love of electrons man, get a Pi and external hard-drive bay setup. My one averages 8W and maxes out at 40W.
Click to expand...
The microserver only has something like a 150W PSU. As far as I have it, it pulls something like 20W at idle, with a single hard drive. It's pretty low power.
 
Arthur said:
Also, allow around 15-20% loss in transmission and inversion. You might get away with 8-10% in practice, but build in some margin as the cost increment is insignificant.

Make sure your MPPT/regulator and DC cabling can handle 30-40% more amps than the pv panel nominal rating. The edge-of-cloud effect can spike current production rather dramatically, and you don't want this to overwhelm your DC circuits and cause a fire.

Lastly, remember to run a Cat6 cable while you're cabling in the panels. This will allow you to add a cam and sensors to keep an eye on things, including panels, which have been known to grow legs.

(I run a 12kW array on 48V into a 12kW inverter and 24 batteries.)
Click to expand...

12 kW? That's impressive. Do you sell back to the grid?
 
Sort-of. Exports are currently netted off from imports before invoice calc, to a max of zero nett consumption. In summer my usage charge is R0 plus of course the fixed meter charge of R143.50.

What's loadshedding again? :p
 
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Arthur said:
Sort-of. Exports are currently netted off from imports before invoice calc, to a max of zero nett consumption. In summer my usage charge is R0 plus of course the fixed meter charge of R143.50.

What's loadshedding again? :p
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I'm guessing you've got ab old school meter that runs backwards?
 
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