Taking lights and internet off the Grid (mostly)

greg_SA

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Awesome little setup actually...

One thing my digging today has shown me, I need to have a much better idea of just how much power I'm planning on putting on the system. Need to overspec it of course, but not to a ridiculous level.
Yep. The difference between a 1kVA and 2 or 3 kVA inverter might not be too pricey. The extra batteries can add up...

I also tried to keep the UPS for low powered stuff only - only wired to lights, the plugs in the lounge and alarm. Trying to have specific plugs at random places in the house run off the UPS gets complicated.
 

ToxicBunny

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@ToxicBunny Where are you?

Different locations have different rules on grid tied/ offgrid.

Notably Cape Town who are anti-solar, and have a lot of hoops to jump through, and a restricted approved product list.
I'm in the wonderful city of Durbs...

I think they're also anti-solar to a degree as well, but thats a bridge I'll properly cross at a later date.
 

Chuckmyster

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Yep. The difference between a 1kVA and 2 or 3 kVA inverter might not be too pricey. The extra batteries can add up...

I also tried to keep the UPS for low powered stuff only - only wired to lights, the plugs in the lounge and alarm. Trying to have specific plugs at random places in the house run off the UPS gets complicated.
Then you have done a pretty awesome job, just keeping the essentials running whilst there is load shedding. It's perfect, and for under R10k you can't go wrong, well done :thumbsup:
 

greg_SA

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Did you split the DB yourself or use an electrician? Is that a 24V system? 100AH batteries?

What is your total load, because if its a 24V system, would 1 bank not be too little to power all that you mentioned for roughly 4 hours without discharging the batteries below 50%
It is a 12V system. I did the work and got it signed off (CoC).
For a typical 2h load shedding session, it has working fine so far. Don't go below 50%. Seldom use more than 400W.
 

The_Librarian

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@bunny - in my experience, not having an inverter and using 12v lights give you the best bang for your buck.

There's a.place in Midrand that offered a fridge converted to a 12v compressor, so you can run it on 12VDC wirhout the overhead of an inverter.

The idea of this is not to make use of any inverters since an inverter also waste a certain percentage of power in converting the DC current up to 240VAC.

Unfortunately not everything can be powered from 12VDC, but if you can get the fridge and most lights on 12VDC then you are halfway there.
 

The_MAC

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Yep. The difference between a 1kVA and 2 or 3 kVA inverter might not be too pricey. The extra batteries can add up...

I also tried to keep the UPS for low powered stuff only - only wired to lights, the plugs in the lounge and alarm. Trying to have specific plugs at random places in the house run off the UPS gets complicated.
The other key consideration is the amount of batteries you have i.e. total AH

You don't want to drain the batteries below the rated discharge depth - otherwise you will be replacing batteries every year, and @ roughly R1800 per battery, if you have 4 then yeah...

This guy sold me many Royal batteries, the marine ones (Royal Delkor DC31 @ R1750 [2 years ago]), he had the best prices and an honest small business - https://www.nrgtechnologies.co.za/
 

ToxicBunny

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@bunny - in my experience, not having an inverter and using 12v lights give you the best bang for your buck.

There's a.place in Midrand that offered a fridge converted to a 12v compressor, so you can run it on 12VDC wirhout the overhead of an inverter.

The idea of this is not to make use of any inverters since an inverter also waste a certain percentage of power in converting the DC current up to 240VAC.

Unfortunately not everything can be powered from 12VDC, but if you can get the fridge and most lights on 12VDC then you are halfway there.
I investigated that option, but it would require a substantial investment in changing everything in the house that is 220V... probably in the range of what I would spend to do the basics of a decent 220V setup anyway.
 

Chuckmyster

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The other key consideration is the amount of batteries you have i.e. total AH

You don't want to drain the batteries below the rated discharge depth - otherwise you will be replacing batteries every year, and @ roughly R1800 per battery, if you have 4 then yeah...

This guy sold me many Royal batteries, the marine ones (Royal Delkor DC31 @ R1750 [2 years ago]), he had the best prices and an honest small business - https://www.nrgtechnologies.co.za/
yup, which is why i go for lead crystal batteries, they don't mind going to any low voltage and they last forever
 

The_Librarian

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I investigated that option, but it would require a substantial investment in changing everything in the house that is 220V... probably in the range of what I would spend to do the basics of a decent 220V setup anyway.
Yeah, money is always the issue.
 

The_MAC

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It is a 12V system. I did the work and got it signed off (CoC).
For a typical 2h load shedding session, it has working fine so far. Don't go below 50%. Seldom use more than 400W.
According to my little calculator I put together, your system is correctly spec's for a 2Hr load shedding session, here in JHB we have 4 hours, so you would need an extra battery - but thats cool because scaling it is easy like that

Capture.JPG
 

Chuckmyster

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According to my little calculator I put together, your system is correctly spec's for a 2Hr load shedding session, here in JHB we have 4 hours, so you would need an extra battery - but thats cool because scaling it is easy like that

View attachment 586612
Holy smoke, 400 watts for DSTV :oops: That's double my usage for my apartment when load shedding kicks in
 

greg_SA

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The other key consideration is the amount of batteries you have i.e. total AH

You don't want to drain the batteries below the rated discharge depth - otherwise you will be replacing batteries every year, and @ roughly R1800 per battery, if you have 4 then yeah...

This guy sold me many Royal batteries, the marine ones (Royal Delkor DC31 @ R1750 [2 years ago]), he had the best prices and an honest small business - https://www.nrgtechnologies.co.za/
Definitely. I'm very aware of the importance of limiting the DoD. Its all a trade off though. Discharging deeper reduces the number of cycles in the battery's life.

However, that being said, my system is for load shedding only, so the batteries only get use very seldom (when load shedding occurs, in the evening or weekend when I'm home). Batteries that are part of a solar system (daily discharge and charge) should be used even more conservatively.

I am using Ritar 100A AGM deep cycle batteries. I also remove them and use them when I go camping (for fridge and lighting, etc).
 

Chuckmyster

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haha, I was just trying to get a 400W load - I actually don't have a decoder any more.
aaaah ok i see, yeah i reckon a 400w load is a nice average to work with most typical home setups during load shedding that lasts 2hrs a day
 

Chuckmyster

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Definitely. I'm very aware of the importance of limiting the DoD. Its all a trade off though. Discharging deeper reduces the number of cycles in the battery's life.

However, that being said, my system is for load shedding only, so the batteries only get use very seldom (when load shedding occurs, in the evening or weekend when I'm home). Batteries that are part of a solar system (daily discharge and charge) should be used even more conservatively.

I am using Ritar 100A AGM deep cycle batteries. I also remove them and use them when I go camping (for fridge and lighting, etc).
Yup, which is why I have 210aH on my inverter that runs the lounge, the batteries are still full after the 2hrs load shedding. I hate draining a lead acid battery.
My UPS in the kitchen however, has lead crystal batteries and they can take a good beating
 
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