Good day Solarists 

total newb here ! 

Hi I’m  wanting to to get a system set up to run totally off grid In western cape need to run hand tools in the day max 3000watts running intermittently 

and a few essentials like fridge freezer   Sound system led lights to run all night ( and day )   

It’s a small setup (5000w) ? But also need it  scalable in the future . Also wanting quality hassle free equipment . any advice welcome 
so many questions thanks in advance 

 

Cheers 
 

Hi @Z100 welcome to the forum.

Your question is a bit too broad for most people. You need to give us a bit more to work with.

If you are serious about being self reliant then you have to start with the basics.

1. Reduce your usage with either a solar geyser, gas stove or heat pump ect.

2. Once you have determined how much electricity you use (peak loads ect.), like now you have decided you want a 5kw inverter the rest is simple a 5kw inverter needs a minimum 10kwh of lithium batteries then ofcource atleast 4kw of pv panels.

3. Lastly if you want to leave municipal feed disconnected a back up generator for when there is no sun for a few days so you can still work with your power tools.

Hope you enjoy your stay.

This was my path to off the grid.
When I say off the grid, in my case I had a switch over between mains and Generator already installed over 10 years ago.
i.e. I manually switched whenever necessary.
3 years ago I had a flat panel geyser conversion done which already assisted in bringing my monthly usage down to 200-250kW/h. TV I ditched over 5 years ago.
Last year I took the dive into an off-grid solar setup which is in my signature.
This was connected to the cable that was the old generator feed cable. I still have a generator change over switch on the solar DB board as well, just in case.
My original changeover switch is now basically my manual switch to use the grid if I really need it. Doesn't happen often. 
My Flat Panel Geyser conversion included the Geyserwise controller which I have now set to only use the element from 10:00 in the morning. 3kW element.  By that time my batteries are normally charged, in fact on cloudless day anywhere between 08:00 and 09:00 they are full depending on the Battery SOC in the morning. In my case 30-45% average. 
Overnight and in the evening there is one fridge, a couple of LED lights, 2 Laptops and a PC. From around midnight it's only some lights and the Fridge and the chargers for electric fence, gate motor and alarm system.

Early evening the kettle is boiled up two or 3 times although I always watch the SOC, and if needed I rather boil water on the gas stove. Yes, I changed to gas stove as well around 5 years ago. Average battery usage from sunset to when batteries charge again 3 to 4 kW
It works well enough and the only thing I really would want to do is to get me another battery. Trying to figure if the odd usage of grid power isn't cheaper than a R25 000 battery considering that I have now averaged R20 grid power per month.
It is not a don't worry and forget system. It means managing my consumption within the limitations and monitoring. A small price to pay for someone that didn't have that much spare cash to splurge for a install and forget system that would handle indiscriminate usage.
ROI calculation at current prices around 8 years. This will come down as the electricity prices go up.

@Buyeye

thanks for the reply , yes there will be no heating items used , that will be on gas, till i upscale. 
I also only be using the tools in day time ( belt sander , skill saws ect )

no heavy machinery . So the main  load will be daytime 3000-5000max 

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

also will have generator for backup possibly wind turbine in future 

what’s  the most economical way to set this up ?  
do I still need 10kwh battery bank if using daytime as peak? 
kind regards 

2 minutes ago, Z100 said:

@Buyeye

thanks for the reply , yes there will be no heating items used , that will be on gas, till i upscale. 
I also only be using the tools in day time ( belt sander , skill saws ect )

no heavy machinery . So the main  load will be daytime 3000-5000max 

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

also will have generator for backup possibly wind turbine in future 

what’s  the most economical way to set this up ?  
do I still need 10kwh battery bank if using daytime as peak? 
kind regards 

The thing with lifepo4 batteries is that they are 0,5C which means a 10kwh battery can only supply 5kw peak loads without tripping if a cloud moves over your panels for a few minutes the 10kwh battery can carry your 5kw inverter without a sweat.

If you get one 4,8kw lifepo4 battery that is reduced to 2,4kw peak loads.

Companies like hubble are offering 1C batteries which pair well with a 5kw inverter and seem to suit people with really low overnight usage.

What most people do with 0,5C batteries is choose a model like the pylontech us3000c or 5000 and just add on when funds allow.

I have a dyness powerbox f10 because I valued a neat box over higher depth of discharge, there have been a lot of mornings where I regretted my 80% dod vs 95% dod. It's funny though because a lot of people still use 80% even though they can do 95%. I've just accepted 1-2kw usage from the grid in morning.

What would you consider low evening usage .. I know it’s all relevant to different uses ect 

but what is roughly considered low usage ? 
Thanks 

2 hours ago, Z100 said:

What would you consider low evening usage .. I know it’s all relevant to different uses ect 

but what is roughly considered low usage ? 
Thanks 

Anything that allows you to run your essentials overnight on a single 3,5kwh or 4,8kwh battery. 

2 hours ago, Buyeye said:

what is roughly considered low usage ?

Bare essentials after dinner. Fridge, alarm, a few LED lights, modem, laptop, phone charging, other appliances on standby mode, maybe 350-400W over a 10-hr period. No appliances, heaters, no geysers, pool pumps or electric blankets, no warming up a midnight snack.

21 hours ago, Z100 said:

Good day Solarists 

total newb here ! 

Hi I’m  wanting to to get a system set up to run totally off grid In western cape need to run hand tools in the day max 3000watts running intermittently 

and a few essentials like fridge freezer   Sound system led lights to run all night ( and day )   

It’s a small setup (5000w) ? But also need it  scalable in the future . Also wanting quality hassle free equipment . any advice welcome 
so many questions thanks in advance 

 

Cheers 
 

Are you a "family" of one or are there other members who will use electricity?

If more than one, they will have to get into the spirit of off-grid too.😂

The Cape is a good place for solar with it's dry summers, and long days. By the sound of your anticipated usage, a 5kW inverter should handle your load easily, and if you get one that is capable of paralleling, there will be no upgrade problems either.

For and off grid system, always get as many panels and batteries as you can afford, and as others have said, a generator to fill in for those rainy days.

I currently have a SunSynk 8.8 kW inverter with 2x Hubble AM-2 batteries, and 6.6 kWp of panels (Aiming for 12.7 kWp of panels later), plus a 7.5 kVA generator when needed.

My usage is +- 1.2 kW (idle) up to sometimes just under 11kW when connected to grid.

Your usage is much more civilized, so a 5kW inverter should be fine.

23 hours ago, Z100 said:

Good day Solarists 

total newb here ! 

Hi I’m  wanting to to get a system set up to run totally off grid In western cape need to run hand tools in the day max 3000watts running intermittently 

and a few essentials like fridge freezer   Sound system led lights to run all night ( and day )   

It’s a small setup (5000w) ? But also need it  scalable in the future . Also wanting quality hassle free equipment . any advice welcome 
so many questions thanks in advance 

 

Cheers 
 

@Z100 off grids nice but its a costly affair if 💯 off grid if the funds available then its a plus+.5Kva is good but when you say 5000w load may a bigger inverter would be better reasons not to push it to max. Then the expensive part storage at least 50kwh. Generator is good but then take in consideration of fuel. Wind turbine would be nice depending on the area residential or if you have neighbors 1km away, a good wind turbine say 1.5kw or 2kw. I currently have a SunSynk 8kw with around 8000watt panels 20KWH lithiumion bank, flat plate collector gets me through a day but depending on the weather ther next day still not completely of grid. My load is around 1kwh I can use the aircon for sometime but by the am battery is around 10 to 15% just my experience.

Edited March 15, 20224 yr by John2

1 hour ago, TimCam said:

Are you a "family" of one or are there other members who will use electricity?

If more than one, they will have to get into the spirit of off-grid too.😂

The Cape is a good place for solar with it's dry summers, and long days. By the sound of your anticipated usage, a 5kW inverter should handle your load easily, and if you get one that is capable of paralleling, there will be no upgrade problems either.

For and off grid system, always get as many panels and batteries as you can afford, and as others have said, a generator to fill in for those rainy days.

I currently have a SunSynk 8.8 kW inverter with 2x Hubble AM-2 batteries, and 6.6 kWp of panels (Aiming for 12.7 kWp of panels later), plus a 7.5 kVA generator when needed.

My usage is +- 1.2 kW (idle) up to sometimes just under 11kW when connected to grid.

Your usage is much more civilized, so a 5kW inverter should be fine.

Thanks that’s helpful , Will be two persons house , but will need to learn the offgrid “laws” of moderation 🙄😂

9 minutes ago, John2 said:

@Z100 off grids nice but its a costly affair if 💯 off grid if the funds available then its a plus+.5Kva is good but when you say 5000w load may a bigger inverter would be better reasons not to push it to max. Then the expensive part storage at least 50kwh. Generator is good but then take in consideration of fuel. Wind turbine would be nice depending on the area residential or if you have neighbors 1km away, a good wind turbine say 1.5kw or 2kw. I currently have a SunSynk 8kw with around 8000watt panels 20KWH lithiumion bank, flat plate collector gets me through a day but depending on the weather ther next day still not completely of grid. My load is around 1kwh I can use the aircon for sometime but by the am battery is around 10 to 15% just my experience.

Hi there , yes I was meaning 5kw maxing , so I think the the sunsynk 5kw By the looks of replies and other posts 

I just need to get a shopping list going and see what’s what 

thanks 

On 2022/03/14 at 10:43 PM, Z100 said:

Good day Solarists 

total newb here ! 

Hi I’m  wanting to to get a system set up to run totally off grid In western cape need to run hand tools in the day max 3000watts running intermittently 

and a few essentials like fridge freezer   Sound system led lights to run all night ( and day )   

It’s a small setup (5000w) ? But also need it  scalable in the future . Also wanting quality hassle free equipment . any advice welcome 
so many questions thanks in advance 

 

Cheers 
 

 

Firstly, you must be able to tell how much power you consume (Watts) per hour and multiply by 12 hours and get the right calculated storage. If you consume 500w per hour you should have 6,0KW storage. When the budget is stable you can add battery bank to be 18kW.

As several posters have mentioned, things are very interrelated. Batteries can usually only supply a certain amount of peak power, so that might determine the size you need.

We're completely off grid on a farm and I run borehole pumps, tools etc of a small Victron 3000VA inverter (2.4kW), 12kWh of DIY lifepo4 batteries and 4kW of panels. And a 2kW genny for the odd rainy days.

It requires a bit of management, but with smart switching I can control all the large loads from a phone or PC or Google hub.

The Victron kit kan handle high startup surges and >3kW loads for a small period, which is handy. We use gas for some cooking and water heating, but most times I cook with a 2kW airfryer off batteries in the evening and we use a electric kettle now as we've got excess capacity ( PV and Solar).

This runs our household of 2 (normally), and my caretaker and wife's cottage as well. The nighttime idle draw of the houses is about ~300W. 

Ian

Edited March 17, 20224 yr by Ian

I've toyed with the idea of moving to a 5kW inverter, but honestly it's not difficult to plan around. And I'm a miser:)

On 2022/03/17 at 4:30 PM, Ian said:

I've toyed with the idea of moving to a 5kW inverter, but honestly it's not difficult to plan around. And I'm a miser:)

Sounds like someone who knows rule one of going offgrid which is reduce usage and yes talk about it to everyone. In this club it's a must to talk unlike fight club. 🤣

Edited March 18, 20224 yr by Buyeye

@Ian

cheers for that , that’s what I’m going to do go small first try work around it sounds like your setup will do me for a Start , then add ( if can ) when I get spare cash ( not often 🙄)

if you dont mind me asking what’s the ball park figure for your setup ? 
complete turn key ? I would be able to mount panels, batteries and maybe cables but not connect … that’s the only knowledge i will have 

thank you 

I don't think my costs would be relevant, as I inherited some of the system when we bought the place(Victron kit). I added panels and built my own Lifepo4 battery. The power forum store would be a good place to start, I reckon. 

If you are up to it you can save on mounting hardware as well. I used Al square tubing screwed into the chromadeck roof, and riveted Al angle sections onto that and the panels. Works like a charm.

Cheers

 

If you want to keep costs low, you can go for Axpert 5kW inverters, they do the job and I saw one for less than 9k.There are different models on the market and not all can work together if you are planning to use more than one in parallel which is the way to overcome load limitations. Buy two small batteries and connect them each on a own inverter, one on L1, one on L2 for example and you can use twice the power at the same time. 5 kW is ok but if you use a washing machine, a dryer and a water kettle at the same time your inverter is at its limits.

If you choose a battery too big, you will not be able to fully charge it, especially in winter. If you take one too small you will run out of power too soon and need to buy more from Eskom. The size depends on your consumption, how big your solar system is and what you want to achieve. The optimum relation between cost and size is different from maximum autonomy and size.

On 2022/03/19 at 11:40 PM, Joerg said:

If you want to keep costs low, you can go for Axpert 5kW inverters, they do the job and I saw one for less than 9k.There are different models on the market and not all can work together if you are planning to use more than one in parallel which is the way to overcome load limitations. Buy two small batteries and connect them each on a own inverter, one on L1, one on L2 for example and you can use twice the power at the same time. 5 kW is ok but if you use a washing machine, a dryer and a water kettle at the same time your inverter is at its limits.

If you choose a battery too big, you will not be able to fully charge it, especially in winter. If you take one too small you will run out of power too soon and need to buy more from Eskom. The size depends on your consumption, how big your solar system is and what you want to achieve. The optimum relation between cost and size is different from maximum autonomy and size.

Hi there Joerg

You mentioned you have seen the Axpert 5KW inverters for less than 9K. Can yo PM me where you saw that ?

Thank you 

11 hours ago, uDuWaR said:

Hi there Joerg

You mentioned you have seen the Axpert 5KW inverters for less than 9K. Can yo PM me where you saw that ?

Thank you 

Just use Google and you will find a number of sellers. Bear in mind these could be Axpert clones and there is risk involved. Some have some badly scaled down software.

On 2022/03/25 at 7:10 PM, Scorp007 said:

Just use Google and you will find a number of sellers. Bear in mind these could be Axpert clones and there is risk involved. Some have some badly scaled down software.

Thanks for the feedback, yeah I have been suspect of the overly cheap inverters. I would rather pay the additional R4k and get an original with warrantees. 

I am totally off grid with a 5Kw Sunsynk inverter and 7 x 430 watt solar panels and 2 Hubble batteries. Gas geyser and stove, run the borehole pump, electric oven washing machine, Iron, tumble drier, and lights at night. Have 80% of my batteries left in the morning on most day's depending if the wife has used the oven at night. I run all my power tools, inverter welder, crosscut saw, table saw. I have not yet been able to get the inverter to kick out on over current. Then I am still looking for work for the system  during the day because just after 10 in the mornings the batteries is full, 11h30 to12h30 the water tanks are full, the rest of the time the system is on idle. I am now thinking of fitting a electric geyser to use some off the power. I am as happy as a pig in S***^^%t with my system. Self installed. I will now see in the winter if I need to add another string off solar panels. Whom knows it might work  as is.

 

1 hour ago, CJE said:

I am totally off grid with a 5Kw Sunsynk inverter and 7 x 430 watt solar panels and 2 Hubble batteries. Gas geyser and stove, run the borehole pump, electric oven washing machine, Iron, tumble drier, and lights at night. Have 80% of my batteries left in the morning on most day's depending if the wife has used the oven at night. I run all my power tools, inverter welder, crosscut saw, table saw. I have not yet been able to get the inverter to kick out on over current. Then I am still looking for work for the system  during the day because just after 10 in the mornings the batteries is full, 11h30 to12h30 the water tanks are full, the rest of the time the system is on idle. I am now thinking of fitting a electric geyser to use some off the power. I am as happy as a pig in S***^^%t with my system. Self installed. I will now see in the winter if I need to add another string off solar panels. Whom knows it might work  as is.

 

Do mean you don't use the municipal grid or that you have disconnected it?