I am totally off grid with no Power supplied from Eskom  because i live on a small holding. There is no services available not even running water or Any other services.

 

Edited April 4, 20224 yr by CJE

Hi @Z100  & @CJE

Apologise for coming to this conversation late, I only get to check the forum when I get a gap...

1. @Z100 - The after hours draw of 2000W/hr is excessive for a small place. If you are running your place like a small holding and needing equipment to provide for animals, then I understand, but a small household can easily get away with under 500W/hr when off-grid. You might have some large power items that need investigating, or you haven't converted some of your basics to be "off-grid" friendly.

2. I have a different estimate based on the consumption you presented - and it will end up being far more expensive than you anticipate if you can't cut down elsewhere:

2.a. You need an Inverter capable of 8kVA or better under load

2.b. If you need to supply at least 3kVA when desired or sometimes constantly for about an hour, then you HAVE to go top of the range that can charge as quickly. Standard Lead Acid/Lead Crystal and many others would get destroyed under such constant high loads, no matter how many you acquire.

2.c. You will need (based on Lead Crystal - LiPO would be more expensive, but a better option) at least 72,000kW available for just 24 hours (your figures). That is either 9 x high end 9kW Pylontechs (LiPo), 32 200Ah batteries, Lead Crystal or equivilent 200Ah - This is a MASSIVE outlay for a small place, and we haven't even discussed panels yet.

2.d. Your invertor and panels would need to be able to charge this system, so this would require an invertor capable of providing at least 9000W/h to the batteries on good sunny days, and as many solar panels to provide that... At 400W/Panel that is at least 23+ panels (not too huge, but this is only optimal on sunny days - look at closer to 30)

3. Your expense is not on Panels or Invertor - It is how to store the power for later use. You can get cheap invertors to supply 8kW/hr, you can get 30+ panels for R2400 a pop, but your storage is going to kill your budget, and that is only for 24hrs.

3.a. Batteries are your deadliest cost. They have to store and provide power so they have to be big. At nearly R5k per decent Lead Acid/Lead Crystal - this is about R160k that might need replacement every 5 years. LiPo will run you closer to R200k.

3.b. You will need to double your battery cost if you need to go closer to 48hrs without sunlight.

Unless you are willing to spend close to a Million rand just to get off grid, this is not viable. Solar electricity is still very expensive compared to Municipal/Eskom costs.

My suggestions are:

1. Reduce EVERY other power draw, no matter how small. LED globes EVERYWHERE; Stop the kids using the Kettle every 20 minutes; Make sure that unness items are definately turned off when not needed; Use a generator for Power Tools if only intermittently used (even look at a gas powered or gas conversion to existing); There are so many things you can change before going the solar route.

2. If you can reduce your overnight power usage to under 1000W/hr then you might find solar economically viable (slightly), but from what you have presented so far a solar installation is not economically viable.

3. Economics aside, as you are still prepared to spend this kind of money to get off grid properly, then you have to do things properly and not on the cheap. Definately go the Victron route with a recommended Victron installer. They can not only give you the best product, but will also (usually) provide the best advice.

On 2022/03/15 at 2:23 PM, Z100 said:

and then at night only running fridge freezer , led lights bits and bobs so only need 2000-3000w at night 

You need to verify that figure somehow. 

At night I run 44" tv, fiber internet, 2 fridge/freezer combos, a freezer, charge cell phones, electric fence and alarm system... and that fluctuates between about 250 and 450 W. Yes... I didn't mention lights. We have some one. They are all LED. So 2 to 3 Kw sounds high. If it's thumbsuck then find a way to get a better figure. Even if it's something crude like this:

1. Read meter at 7pm
2. Read meter again at 7am
3. The difference is the kw/h consumed in 12 hours
4. Divide by 12 to get a ballpark figure for your AVERAGE (not maximum) load.

If 2 to 3Kw is not a thumbsuck then going solar is going to be expensive for you. That consumption will flatten a 10kw/h battery in 4 hours.

On 2022/03/15 at 2:23 PM, Z100 said:

and then at night only running fridge freezer , led lights bits and bobs so only need 2000-3000w at night 

Are you saying you will only consume upto 3 kW for the whole night, i.e. if you had a 5 kW battery by the morning there would still be 2 kW of power left?

This is easily doable. 👍

 

.🙄

Edited April 5, 20224 yr by TimCam
Double Post

To go off grid is a total mind set change. I had a KWH meter in My DB panel For more than a Year and I recorded the KWH usage every month. I then id my solar according to the results. I still find that the system is to large and i Have a lot of wasted energy generated  so much so that i am thinking of fitting a normal geyser to use some of the energy and then remove the gas geyser or put it on standby.

On 2022/04/06 at 2:52 PM, CJE said:

To go off grid is a total mind set change. I had a KWH meter in My DB panel For more than a Year and I recorded the KWH usage every month. I then id my solar according to the results. I still find that the system is to large and i Have a lot of wasted energy generated  so much so that i am thinking of fitting a normal geyser to use some of the energy and then remove the gas geyser or put it on standby.

You obviously live somewhere, where you don't have weeks of bad weather, enjoy the solar.

Hi,

I am hoping to install 7kw of solar PV, want max charging at 2.5kw, basically alot of clipping, this is to achieve a reasonable supply in cloudy weather, most of the solar charge controller suppliers state the array output max 1.5 charging output, is there a solution pleaseregards Philip

 

Do o need a SOC certificate when I am totally off grid

On 2025/03/22 at 3:34 PM, Annamarie said:

Do o need a SOC certificate when I am totally off grid

For insurance purposes, yes. And was mentioned on the forum as well, that any system above 53v needs a COC, since your house uses 220v+.