Taking lights and internet off the Grid (mostly)

ToxicBunny said:
I'm still scoping everything.. but heavy draw items can live off the "off-grid" system... its too expensive to take things like a tumbledryer/microwave etc off grid for the moment.
Click to expand...
I totally agree, but even a 1500w grid tied system is appealing for me as i am a bachelor
https://www.sustainable.co.za/sustainable-co-za-1-5kwp-grid-tied-system-solar-power-kit.html
Your night time requirements should be easily affordable, but that constant day to day battery drain is gonna kill your batteries in a short few years.
Unless you go lithium
Just a pity it is still so expensive
https://www.sustainable.co.za/solar-power/solar-storage-batteries/lifep04-batteries.html
 
Chuckmyster said:
I totally agree, but even a 1500w grid tied system is appealing for me as i am a bachelor
https://www.sustainable.co.za/sustainable-co-za-1-5kwp-grid-tied-system-solar-power-kit.html
Your night time requirements should be easily affordable, but that constant day to day battery drain is gonna kill your batteries in a short few years.
Unless you go lithium
Just a pity it is still so expensive
https://www.sustainable.co.za/solar-power/solar-storage-batteries/lifep04-batteries.html
Click to expand...

Thats what I ahve to figure out.. my networking and entertainment centre usage is where I have daytime usage.... that needs to be figured out and then sized and see if its affordable.

Either that, or have a smart inverter that will only draw off the batteries in the evening or when the grid is off...
 
ToxicBunny said:
Thats what I ahve to figure out.. my networking and entertainment centre usage is where I have daytime usage.... that needs to be figured out and then sized and see if its affordable.

Either that, or have a smart inverter that will only draw off the batteries in the evening or when the grid is off...
Click to expand...
And get your geyser off the grid 1st. If you're a family man get your stove off as well to gas.
 
And the fleecing has begun - was looking at getting a temporary inverter set up to replace all my UPSs till I can get something more permanent sorted - Makro was selling the Ellies 1200W kit for R6999 yesterday. Was unable to get away to go and get it yesterday morning, so thought I would do it yesterday afternoon. They "ran out of stock". Had a look this morning and the price went up by a R1000 and it is now selling for R7999 and stock is available again. Builders is selling it for R6500 but no local stock available - they will have to order it.
 
Don't do it. The 600W inverter alone will suffice (12V system), then go and buy some decent batteries, 2 in parallel. You will get a longer life-span on them and longer back-up time.

You probably don't need 1200W, and it requires the 2 batteries in series. The Ellies Kit is a rip-off, the Ellies inverter on its own is still "ok"
 
The_MAC said:
Don't do it. The 600W inverter alone will suffice (12V system), then go and buy some decent batteries, 2 in parallel. You will get a longer life-span on them and longer back-up time.

You probably don't need 1200W, and it requires the 2 batteries in series. The Ellies Kit is a rip-off, the Ellies inverter on its own is still "ok"
Click to expand...
If you do mod your UPS like i did mine with truck batteries just remember it runs hotter after load shedding as it takes longer to recharge the batteries.
I have heard of peoples UPS's blowing up.
Touch wood, my APC UPS's at home are happy and don't get too warm
 
Last edited:
thechamp said:
A 12V system with 4 * 100Ah batteries connected in parallel gives you a total combined capacity of all the 4 batteries 400Ah, the problem with this will always be the high operating currents needed to give you the power you need, the solution now becomes a 24V system, with the same number of batteries your capacity is now halved to 200Ah but the operating current is lowered for the same output power, going to 48V will mean your capacity is lowered and the result is equal to the capacity of only one battery 100Ah, compare that to the 12V and the 24 volts and you will see how reduced is the battery capacity, battery capacity is directly propotional to the run time you will enjoy on your system.
Click to expand...
That's not how you calculate usable power, at all

4 100ah batteries in parallel at 12v each gives you 4.8kwh (I'm not taking losses and efficiency into account here for the sake of simplicity)
(2 *100ah) in parallel with (2 * 100ah) - because its two strings of two batteries each - at 24v per string gives you 4.8kwh (200ah * 24v)
100ah (all in series) at a total of 48v gives you 4.8kwh

In this example 24v would be the ideal voltage because you never connect all your batteries in series as you will never know if one of them is a donkey which will make the other 3 work extra hard and kill them quicker.

If TB however uses 8 100ah batteries the obvious choice then becomes a 48v system with 2 strings of 4 batteries each for a total of 9.6 units of power
 
Last edited:
I agree with The_MAC, for what ToxicBunny wants, a 600 watt modified 12 volt inverter with 2 x 100 AH lead acid batteries is all he's gonna need.
Maybe add 1 solar panel with a 20 Amp controller.
That will very comfortably run at least 10 led lights and a 55" TV set + DSTV Explorer decoder, or a desktop computer.
In fact all that will only be around 200 watts.
Then later on if you want, design a fancy system when you have some experience and lots of money :)
During load shedding, only 2 hours, you just change your habbits slightly.
 
ProAsm said:
I agree with The_MAC, for what ToxicBunny wants, a 600 watt modified 12 volt inverter with 2 x 100 AH lead acid batteries is all he's gonna need.
Maybe add 1 solar panel with a 20 Amp controller.
That will very comfortably run at least 10 led lights and a 55" TV set + DSTV Explorer decoder, or a desktop computer.
In fact all that will only be around 200 watts.
Then later on if you want, design a fancy system when you have some experience and lots of money :)
During load shedding, only 2 hours, you just change your habbits slightly.
Click to expand...
All those numbers you throw around there is basically what my lounge is. And after 2.5hrs load shedding my batteries are still sitting at 12.7v ea.
Thank goodness, coz lead acids do NOT like going flat, they were never designed to.
:thumbsup:
PS On solar chargers I have learnt my lesson over 4 years experimenting, pay the extra and go MPPT, I have thrown all my PWM controllers in the bin.
 
Chuckmyster said:
All those numbers you throw around there is basically what my lounge is. And after 2.5hrs load shedding my batteries are still sitting at 12.7v ea.
Thank goodness, coz lead acids do NOT like going flat, they were never designed to.
:thumbsup:
PS On solar chargers I have learnt my lesson over 4 years experimenting, pay the extra and go MPPT, I have thrown all my PWM controllers in the bin.
Click to expand...
I agree with you regarding the controller but there is a big price difference.
I use the Ecco 20A PWM jobby and it has served me very well, less effecient but does the job.
Regarding batteries... LOL here I have learnt a big lesson, especially when it comes to the battery chargers available on most inverters.
Nothing beats a good old Sealed Lead Acid, the cheapest you can find and replace them every 3 to 5 years.
I'm using Silver Calcium atm, and although they still are good, I doubt very much they will reach their predicted 10 life span.
A friend of mine had 200 AH Gel batteries which he had to dump after 3 years, and replaced them with lead acid :)
Charging these fancy batteries is a very critical job and the slightest hicup and they die.
 
ProAsm said:
I agree with you regarding the controller but there is a big price difference.
I use the Ecco 20A PWM jobby and it has served me very well, less effecient but does the job.
Regarding batteries... LOL here I have learnt a big lesson, especially when it comes to the battery chargers available on most inverters.
Nothing beats a good old Sealed Lead Acid, the cheapest you can find and replace them every 3 to 5 years.
I'm using Silver Calcium atm, and although they still are good, I doubt very much they will reach their predicted 10 life span.
A friend of mine had 200 AH Gel batteries which he had to dump after 3 years, and replaced them with lead acid :)
Charging these fancy batteries is a very critical job and the slightest hicup and they die.
Click to expand...
Wow that is crazy.
Agree with you on so many points but where your friend dumped the Gel I cannot relate as i have never owned any.
I was very sceptical years ago around 2011 when my local battery supplier Deltec in Paarden Eiland was trying to convince me to sway away from lead acid to lead crystal. Took me a year and a bit to eventually try it out and I have never looked back.
For me, just my own experience owning my own and in the film industry renting them out they have overall proven to be rock solid. They can take a good beating.
 
So have a few questions, as with some new humans on the planet, I need to be sure we have electricity . Like Toxic Bunny, want to start with a system that allows me to power the basics initially, lights, network, security and then have solar to hopefully then reduce or eliminate reliance on Escum.

I have full LED light setup inside/outside, geysers turned on manually when needed (but will be managed by Sonoff HA soon), and have gas stove.

Some questions:-
1. Can someone provide a link or excel document that allows you to plug in your numbers to see what type of system you require. For example, during the day, my house on average uses 360w/400w . When the pool pump is on, it bumps to 1.1Kw. At Night (if geysers are off), with outside lights on, house uses 550w.

2. I've seen some of the pics of the setups posted in this thread and while they look good - I can't do this for my house as my DB board is in my passage which means I can't do put the batteries, there. My ultimate aim is that the entire house should be powered so how the heck will this be done if for example, I put the inverter, etc all in my garage (seems like a sensible place for me)? More importantly, if I build the system to only charge specifics plugs/circuits ... how much work is that from an electricians point of view?

3. While Solar is the future, a generator could meet my needs more cost effectively for the short term. That is a 6-7kva generator to power the whole house? I could hopefully get a quite generator. Am I being stupid?

4. Has anybody built a mini-powerbank UPS solution for just their electronic network equipment. Eg a Romoss 30000mAh power bank to keep the router and fibre box running? Or something like this ? https://www.amazon.com/Beatit-18000...ag=4140286|bing.com|||36,70,10,75,37,31,47|1|
 
It's the same thing, just represented differently. All conforms to ohm's law.

AH is a perfectly acceptable unit of measure. If you know your load in W, and the operating V (230V), you can easily calculate the current of the load.

You know a 100AH battery can deliver 100A for 1Hr until its completely flat, so then you can calculate the backup-time from there.

I prefer this technique as its easy to calculate backup-time in your head on the fly, in order to preserve the batteries (50% depth of discharge).
 
@InternetLuddite

1. A good place to start
https://www.leadingedgepower.com/shop/help-advice-faq/solar-calculators/cable-size-calculator.html

2. I use a seperate DB board with seperate wiring, leave the house one alone else you get bogged down with compliance certificates etc.

3. For load shedding, a 5 kw generator is the answer, costs about R6k and uses 1.5 litres/hour
For the price of a decent solar installation you can buy and run the generator for many many hours.

4. For the cost of a power pack you may as well get a generator and run the whole house.
Just switch off the geyser and stove.
 
ProAsm said:
During load shedding, only 2 hours, you just change your habbits slightly.
Click to expand...

We had about 4 hours last night in Parklands, Cape Town! I was planning for a 2.5 hours capable system but seems like 4 will be more prudent... hectic...
 
Chuckmyster said:
Yeah the thing that puts me off going off the grid completely is the cost of batteries, and you have to replace them every 5 to 10 years, eina.
I want to go grid tied whereby you have no batteries but you generate say 3kw during the day, anything you consume beyond that it now taps into eskom and uses what it needs.
As soon as your demand goes below 3kw it is then purely free from what you are generating.
That way you run the expensive things during the day for "free" such as washing machines, swimming pool pumps, air con all day (heater in winter) etc etc.

Drawback to this is it will only work during the day, Duh.
And when there is load shedding the gridtied unit also shuts down (stupid, but it does).

But its a small price to pay knowing you can generate free electricity for decades.
Click to expand...
Only shuts down if the design was incorrect in the first place. Systems like this cannot be designed piecemeal. If you do that you find you can't upgrade without replacing. Alt power becomes a huge expense and a maintenance issue if done piecemeal.
 
Last edited:
InternetLuddite said:
So have a few questions, as with some new humans on the planet, I need to be sure we have electricity . Like Toxic Bunny, want to start with a system that allows me to power the basics initially, lights, network, security and then have solar to hopefully then reduce or eliminate reliance on Escum.

I have full LED light setup inside/outside, geysers turned on manually when needed (but will be managed by Sonoff HA soon), and have gas stove.

Some questions:-
1. Can someone provide a link or excel document that allows you to plug in your numbers to see what type of system you require. For example, during the day, my house on average uses 360w/400w . When the pool pump is on, it bumps to 1.1Kw. At Night (if geysers are off), with outside lights on, house uses 550w.

2. I've seen some of the pics of the setups posted in this thread and while they look good - I can't do this for my house as my DB board is in my passage which means I can't do put the batteries, there. My ultimate aim is that the entire house should be powered so how the heck will this be done if for example, I put the inverter, etc all in my garage (seems like a sensible place for me)? More importantly, if I build the system to only charge specifics plugs/circuits ... how much work is that from an electricians point of view?

3. While Solar is the future, a generator could meet my needs more cost effectively for the short term. That is a 6-7kva generator to power the whole house? I could hopefully get a quite generator. Am I being stupid?

4. Has anybody built a mini-powerbank UPS solution for just their electronic network equipment. Eg a Romoss 30000mAh power bank to keep the router and fibre box running? Or something like this ? https://www.amazon.com/Beatit-18000mAh-Portable-Starter-Charging/dp/B01MY9FZM4/?tag=aboutcom02lifewire-20&ascsubtag=4140286|bing.com|||36,70,10,75,37,31,47|1|
Click to expand...

Below is the calculator I use. It's very basic, but does the job.

UPS.JPG
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X