Good Morning

Today we are considering going the Solar Route considering rising cost of living and most importantly - Eskom and their Electricity Un-Availability Factor, I work from from home, we require a power source.. the chosen system will be dedicated for daytime use:

Inverter and Panels only and battery for now.. Before the following is set in stone I would like some advice and opinions other than my own from what I presume is normal. 

So in essence of our theoretical world of perfect supply will highlight Eskom's exceptional performance (not the case) - it would also dictate, I am happy, food is kept frozen, we are able to carry out the task at hand for the day and nothing gets impacted, unfortunately that is not the case (very unhappy at this point and frustrated).

Hence why we all have chosen to become somewhat independent and I have chosen to start this topic not just for me but the many other people who share the same sentiment.

Lets Go... So I wanted to be safe guarded for day time and night time usage which is why I am opting for Solar(Inverter and Panels the battery will be added at a later point in time) this will be for day for time usage and in the event the grid collapse which in all likelihood is a reality, therefore we have chosen to go for a smaller backup genny to keep the fridge and and freezer running throughout most part of the night. We heed the call of all techies to avail yourself 🤣 

The Required Advice pertains to details and wiring:

Independently selected power sources require a change over switch... is needed... ^The Inverter Output and Genny to Changeover (CO) (C/O) switch to the Distribution Board (Main DB). 

At a later stage we will add battery storage and eventually complete the full Installation, In theory is this as simple as it seems or am I missing something. please elaborate...  your Input will be much appreciated! Enjoy!!

Edited March 6, 20233 yr by SunDayFunDay

Please note that most inverters cant run without a battery and grid present.  Some can do it but it is not ideal, an inverter needs the batt or grid as a backup when there is suddenly cloud cover. 

20 minutes ago, SunDayFunDay said:

Inverter and Panels only and battery for now.. Before the following is set in stone I would like some advice and opinions other than my own from what I presume is normal.

That's not going to protect you against load shedding during the day. 

This is what's called a grid-tie system. It will supplement your grid feed while there is a grid feed. 

To produce AC output of the kind your home needs, the inverter needs a reference. It can get that two ways 

1) Grid. My system matches grid voltage and phase whilst there is grid. This is a safety requirement. 

2) output from converting DC in the battery to 230V AC. Note that whilst this is happening, your system must disconnect from grid - another safety requirement. 

8 minutes ago, Jacques Ester said:

Please note that most inverters cant run without a battery and grid present.  Some can do it but it is not ideal, an inverter needs the batt or grid as a backup when there is suddenly cloud cover. 

Pretty Much Similar to a car or genny for the starter, without a battery it will indeed not function that seems correct, could I use batteries just for standby power if i am correct without using the inverter output during the night, whilst keeping them charged up with a genny?

My advice would be an inverter that can do what you are aiming for, go light on panels and battery at first, back up the bare essentials at first, then grow the PV and solar sides. 

This really means a 50v inverter. Otherwise as the battery bank grows the current will get high and you risk burning out cables. Also you have better choices in 50V batteries. 

 

3 minutes ago, Bobster. said:

That's not going to protect you against load shedding during the day. 

This is what's called a grid-tie system. It will supplement your grid feed while there is a grid feed. 

To produce AC output of the kind your home needs, the inverter needs a reference. It can get that two ways 

1) Grid. My system matches grid voltage and phase whilst there is grid. This is a safety requirement. 

2) output from converting DC in the battery to 230V AC. Note that whilst this is happening, your system must disconnect from grid - another safety requirement. 

would a standby battery not work? shouldn't a Off grid inverter or Hybrid sense PV as Priority?

9 minutes ago, Bobster. said:

That's not going to protect you against load shedding during the day. 

This is what's called a grid-tie system. It will supplement your grid feed while there is a grid feed. 

To produce AC output of the kind your home needs, the inverter needs a reference. It can get that two ways 

1) Grid. My system matches grid voltage and phase whilst there is grid. This is a safety requirement. 

2) output from converting DC in the battery to 230V AC. Note that whilst this is happening, your system must disconnect from grid - another safety requirement. 

so the battery again also does not have the tech to charge and discharge at the same time???

Do it (or have it done) properly. You want isolators on all inputs and outputs of the inverter. Lightning arrestors on the incoming PV lines. 

To have a system that gets you through load sheds and saves you money is much easier & cheaper than going completely off grid. The latter requires the capacity to get through 3 or 4 consecutive overcast days. 

Gennies are not illegal, but in suburban areas a lot of gennies running at night gets noisy. 

Run a hybrid system. On overcast days I can always find a slot when the power is on and force charge my batteries then if needs be. 

12 minutes ago, SunDayFunDay said:

would a standby battery not work? shouldn't a Off grid inverter or Hybrid sense PV as Priority?

Ok. You mustn't mistake me for an engineer or anything like that. I'm an owner who has been around a few blocks. 

Most modern inverters are configurable as to the priorities you mention. They usually prioritise PV by default. In my case it will use PV first to power the property, then any excess is used to charge batteries. Then when the sun has gone down it runs off batteries within limits I have set. 

But prioritising PV is only part of the solution. The output from your PV is DC. It needs to be converted to AC, but what voltage and frequency? Hence it needs a reference. 

18 minutes ago, SunDayFunDay said:

so the battery again also does not have the tech to charge and discharge at the same time???

As stated, I'm no engineer. I hope somebody with more technical chops gives you an answer.

24 minutes ago, Bobster. said:

My advice would be an inverter that can do what you are aiming for, go light on panels and battery at first, back up the bare essentials at first, then grow the PV and solar sides. 

This really means a 50v inverter. Otherwise as the battery bank grows the current will get high and you risk burning out cables. Also you have better choices in 50V batteries. 

 

recommendations for inverters which can cater to the desired application??

17 minutes ago, Bobster. said:

Do it (or have it done) properly. You want isolators on all inputs and outputs of the inverter. Lightning arrestors on the incoming PV lines. 

To have a system that gets you through load sheds and saves you money is much easier & cheaper than going completely off grid. The latter requires the capacity to get through 3 or 4 consecutive overcast days. 

Gennies are not illegal, but in suburban areas a lot of gennies running at night gets noisy. 

Run a hybrid system. On overcast days I can always find a slot when the power is on and force charge my batteries then if needs be. 

I only predicted capacity for night time use and you are 100% percent correct, I might need more than just 3 to 5KWH for the 3-4 days hence grid-tied/hybrid might be a better option and the cost to add additional capacity at this point adds a heavy financial upfront is why I wanted the genny connected... 

13 minutes ago, Bobster. said:

Ok. You mustn't mistake me for an engineer or anything like that. I'm an owner who has been around a few blocks. 

Most modern inverters are configurable as to the priorities you mention. They usually prioritise PV by default. In my case it will use PV first to power the property, then any excess is used to charge batteries. Then when the sun has gone down it runs off batteries within limits I have set. 

But prioritising PV is only part of the solution. The output from your PV is DC. It needs to be converted to AC, but what voltage and frequency? Hence it needs a reference. 

fully understood but if a the grid collapse how does anybody using solar have a reference point for the inverter to sense frequency? would the output requirements not be autosensing???

17 minutes ago, SunDayFunDay said:

fully understood but if a the grid collapse how does anybody using solar have a reference point for the inverter to sense frequency? would the output requirements not be autosensing???

From inverting the output from the batteries. When there is no grid, my system inverts the power from the batteries to a nice 230V AC at 50Hz. 

You asked earlier about batteries charging & discharging at the same time. My instinct is to say no, but then how my does my system work when there is no grid? 

I am sure about the inverter needing a reference, but going further than that is something I don't have the knowledge to do. Sorry.

okay, I now understand point of reference would mean power source on a cloudy or rainy day, knowing now.

I would have the option to split the DB between essentials and non essentials and have a point of reference for the inverter (standby battery) or use the current DB with a Genny which can feed the Essentials and Non Essentials in the night time, would this work...

My DB placement is also not ideal, anybody know how far away the Inverter can be placed from the Main DB???

1 hour ago, Bobster. said:

To have a system that gets you through load sheds and saves you money is much easier & cheaper than going completely off grid

That is the ideal way to go.
Problem here is that these systems are not affordable for most users

2 minutes ago, SunDayFunDay said:

My DB placement is also not ideal, anybody know how far away the Inverter can be placed from the Main DB???

Can be as far as your copper cabling budget allows...
The further away the more expensive the wiring is going to be.

How To Safe Guard For Total Grid Collapse?

Off-Grid inverter or hybrid inverter with an absolute minimum of 5kW battery would be the way to go.

You can run some inverters without a battery during GOOD sunshine, but this becomes iffy unless you full 100% understand how to manage your loads within the specs of said inverter.
Not an easy task, I have a spare growatt spf5000es which can run 100% ok without a battery but believe me it is not that simple, I have tried and it was painful to manage the loads.

1 hour ago, Bobster. said:

To have a system that gets you through load sheds and saves you money is much easier & cheaper than going completely off grid

3 minutes ago, WannabeSolarSparky said:

That is the ideal way to go.
Problem here is that these systems are not affordable for most users

 

yeah I see people poking at my cost cutting maneuvers, suffice to say the battery bank capacity alone for 3 - 4 days of rain will chow my pockets in all honesty!!  🙄

1 minute ago, SunDayFunDay said:

 

yeah I see people poking at my cost cutting maneuvers, suffice to say the battery bank capacity alone for 3 - 4 days of rain will chow my pockets in all honesty!!  🙄

It's a problem. One solution is a generator, but you need a decent one, you have to have it serviced, diesel isn't getting any cheaper.

We all need alternate power, but the vast majority of people in this country can't afford it. This is why trolley inverters are selling so well at the moment. I think of my mother, who we have given some protection. She gets her TV on, she has some lights, she has a small gas stove for cooking. That's nowhere near off-grid, and it doesn't save any money, but at least you don't sit twiddling your thumbs in the darkness.

So that kind of solution is far from ideal, but it's a useful tradeoff because at least you have some stuff on and so she can make a cup of tea, watch TV, do her knitting. She has to go shopping more often, because she doesn't want to load the freezer for fear of losing the contents.

So that's what you get for about 15K! A sum which is more affordable, but still beyond many people's means.

2 minutes ago, WannabeSolarSparky said:

How To Safe Guard For Total Grid Collapse?

Off-Grid inverter or hybrid inverter with an absolute minimum of 5kW battery would be the way to go.

You can run some inverters without a battery during GOOD sunshine, but this becomes iffy unless you full 100% understand how to manage your loads within the specs of said inverter.
Not an easy task, I have a spare growatt spf5000es which can run 100% ok without a battery but believe me it is not that simple, I have tried and it was painful to manage the loads.

We've managed to get our bill down by +-R1700 with switching the geyser off after about a hour or two..

I also have faults and hotspots that need to be sorted out, we have a ceiling fan and every time we switch it on goes on the wire (in the db) heats up had sometimes the entire circuit connected to the fan trips the E/L and the individual circuit, the geyser burst a few times and circuits tripping..

it was like this when we moved in and its the same problem, I'm on a mission to sort it out we even had the insurer check it out the wire still heats up for the ceiling fan and occasional tripping of the circuits connected on the same line, the geyser seems fine for now haven't had a problem for while with the geyser.. gate motor is also completely not working or powering up..

 

13 minutes ago, Bobster. said:

It's a problem. One solution is a generator, but you need a decent one, you have to have it serviced, diesel isn't getting any cheaper.

We all need alternate power, but the vast majority of people in this country can't afford it. This is why trolley inverters are selling so well at the moment. I think of my mother, who we have given some protection. She gets her TV on, she has some lights, she has a small gas stove for cooking. That's nowhere near off-grid, and it doesn't save any money, but at least you don't sit twiddling your thumbs in the darkness.

those inverter are just a eye sore for me, knowing their capabilities and being a bit tech savvy buying those gives me the butterflies, especially considering the fact that everybody is selling them, I am not even enthused by the price point and even more so by their features, running a kettle would be justified if it gets damaged its cheap to replace but monitors, routers tv sets and fridges is not worth the risk. 

I have eyes set and pockets ready for inverter that you know is value for money and at least it wont be in the way of the dogs which run through the house 🦮  

31 minutes ago, WannabeSolarSparky said:

Off-Grid inverter or hybrid inverter with an absolute minimum of 5kW battery would be the way to go.

5kw is not bad, short term for use during load shedding and to cut the electric bill, depending on the pockets of course - most homes these days need about 15kw upwards to be fully independent and battery storage is a must for night time usage whether the SOC is capped or not, usage will dictate the size of the battery bank, your load or startup voltage of appliance running simultaneously will dictate the size of the inverter or requirements...

For me (Loads):

Its the  Double Door Fridge, Chest Freezer, Lights, Alarm and CCTV, Gate Motor, Router, ONT and TV Set Up... It doesn't seems bad in terms of load but I am not sure about startup voltages ect would have to do some digging around to find out all the technical jargon..

1 minute ago, SunDayFunDay said:

Its the  Double Door Fridge, Chest Freezer, Lights, Alarm and CCTV, Gate Motor, Router, ONT and TV Set

That is pretty close to my base load profile.
Managed correctly you would get away with 10kW battery bank quite comfortably.
You can start with 1 battery and as budget allows add more.

There are many good off-grid inverters, but again, aim for something decent more in the line of hybrid like the sunsynk paired with some good solar panels.
I speak from 2+ years real world experience, the sunsynk is an awesome bit of kit and will pay for itself over and over for sure.