Good day

We are using a max of 14kWh per day. We are on prepaid. I worked on exact daily usage and monthly average usage. Our usage is normally 12 units but had a few days of 14kWh. All big appliances are on timers spread from 8:00 till 17:00. 

Will this system cover at least 85% of our Eskom usage?

1 X Growatt SPF5000ES hybrid inverter 

1 X Hubble 5.5kWh lithium battery 

8 X 550W Canadian solar panels

22 minutes ago, Nature said:

14kWh

That should give you an average of 580 watts per hour.
If you do not have too many major spikes over 5000 watts then you should realise that 85% easily.
Based on having a single 5kWh battery you may need to look at your loads more carefully for during the night.
A single battery may make it through the night down to 20% provided your geyser does not come on during the night.
You mentioned your big appliances are set to run on timers during the day, so maybe move your geyser timer to midday.
And ideally all your big loads should run after the battery is fully charged, mostly with that amount of panels and IF good sunny day then the battery should be charged up a while before before midday.

Edited March 19, 20233 yr by WannabeSolarSparky

Pretty much the same setup I am running and also pretty similar usage. Also on prepaid, but my solar is off grid. Use a change over switch if and when the need really arises. Yes, I have a few more panels but I also have no TV.
Do all high powered demand sequentially in the day. Installed a gas/electric hob combo. So mostly cooking with gas when solar energy is absent. In the day, why waste gas when having excess solar.
Wintertime nights are long, so it's tight with the single battery. Financially I am trying to justify a second battery, but rather using a R100 worth of electricity a month from Eskom at R2/kWh is a lot cheaper than a second battery. That makes R1200 per year or R12 000 over ten years. Yes, the price will go up but it's a lot cheaper that another R30 000+ battery that will need replacing in 10 years. Depending where the electricity costs go I may still get one.
With proper management you can make the system work for you and be independent.

  

38 minutes ago, WannabeSolarSparky said:

That should give you an average of 580 watts per hour.
If you do not have too many major spikes over 5000 watts then you should realise that 85% easily.
Based on having a single 5kWh battery you may need to look at your loads more carefully for during the night.
A single battery may make it through the night down to 20% provided your geyser does not come on during the night.
You mentioned your big appliances are set to run on timers during the day, so maybe move your geyser timer to midday.
And ideally all your big loads should run after the battery is fully charged, mostly with that amount of panels and IF good sunny day then the battery should be charged up a while before before midday.

Thank you very much. The geyser is on from 13:00 to 14:30. My plan is to spend a max of R200 on electricity under sunny conditions. 

1 minute ago, Nature said:

My plan is to spend a max of R200 on electricity under sunny conditions.

With careful use you should easily achieve that.
I have mine down to under R25 per month regardless of the weather
BTW I am also on prepaid, so the result is the system is paying for itself over and over and over

 

20 minutes ago, zsde said:

Pretty much the same setup I am running and also pretty similar usage. Also on prepaid, but my solar is off grid. Use a change over switch if and when the need really arises. Yes, I have a few more panels but I also have no TV.
Do all high powered demand sequentially in the day. Installed a gas/electric hob combo. So mostly cooking with gas when solar energy is absent. In the day, why waste gas when having excess solar.
Wintertime nights are long, so it's tight with the single battery. Financially I am trying to justify a second battery, but rather using a R100 worth of electricity a month from Eskom at R2/kWh is a lot cheaper than a second battery. That makes R1200 per year or R12 000 over ten years. Yes, the price will go up but it's a lot cheaper that another R30 000+ battery that will need replacing in 10 years. Depending where the electricity costs go I may still get one.
With proper management you can make the system work for you and be independent.

  

Thank you for the feedback. We are also on gas for cooking and coffee. An extra battery is not an option at this stage. I would rather consider adding 2 panels to reduce the battery charging time. This system must save us a lot of money taking into account future electricity increases. 

6 minutes ago, Nature said:

The geyser is on from 13:00 to 14:30.

Today we were blessed with so much sun again. Battery was full just after nine and there was sufficient solar to start the geyser shortly after.

Geyser was at max just before 10.

5 minutes ago, WannabeSolarSparky said:

With careful use you should easily achieve that.
I have mine down to under R25 per month regardless of the weather
BTW I am also on prepaid, so the result is the system is paying for itself over and over and over

 

R25 a month sounds very good 🙂. I do not want to spend money on electricity anymore. Eskom pushed us in to a corner and in future I don't want to depend on them. 

1 minute ago, Nature said:

This system must save us a lot of money taking into account future electricity increases.

Depending on your pre-paid rate you should save at the very least R750pm
R750 X 12 = R9000 per year
After 1st year you can add those xtra panels.
After that you need to save some of those savings for future battery replacement

1 hour ago, Nature said:

Good day

We are using a max of 14kWh per day. We are on prepaid. I worked on exact daily usage and monthly average usage. Our usage is normally 12 units but had a few days of 14kWh. All big appliances are on timers spread from 8:00 till 17:00. 

Will this system cover at least 85% of our Eskom usage?

1 X Growatt SPF5000ES hybrid inverter 

1 X Hubble 5.5kWh lithium battery 

8 X 550W Canadian solar panels

You did not specify location. If in Cape Town you will probably be able to cover more than 85% of electricity usage in summer if you can mange the loads during the evening.

In winter this will drop to about 50% of electricity usage, you will need more panels for the Cape winter.

14 minutes ago, zsde said:

Today we were blessed with so much sun again. Battery was full just after nine and there was sufficient solar to start the geyser shortly after.

Geyser was at max just before 10.

This is what I need.

Please explain the following to me

Does the solar charge the battery and carry the load without using Eskom? I don't want any Eskom during a sunny day. Are there settings that will prevent Eskom interfering with my plans 😅

46 minutes ago, zsde said:

Pretty much the same setup I am running and also pretty similar usage. Also on prepaid, but my solar is off grid. Use a change over switch if and when the need really arises. Yes, I have a few more panels but I also have no TV.
Do all high powered demand sequentially in the day. Installed a gas/electric hob combo. So mostly cooking with gas when solar energy is absent. In the day, why waste gas when having excess solar.
Wintertime nights are long, so it's tight with the single battery. Financially I am trying to justify a second battery, but rather using a R100 worth of electricity a month from Eskom at R2/kWh is a lot cheaper than a second battery. That makes R1200 per year or R12 000 over ten years. Yes, the price will go up but it's a lot cheaper that another R30 000+ battery that will need replacing in 10 years. Depending where the electricity costs go I may still get one.
With proper management you can make the system work for you and be independent.

  

Those are impressively low night time usage numbers.

5 minutes ago, Nature said:

Does the solar charge the battery and carry the load without using Eskom?

If you manage your loads correctly then yes.
You can also FORCE yourself by keeping eskom switched off most of the time and only switch it on if you really need some extra power.
That's what I do now.
Those growatt spf5000 units are quite robust and should handle well managed loads quite comfortably

Edited March 19, 20233 yr by WannabeSolarSparky

16 minutes ago, WannabeSolarSparky said:

Depending on your pre-paid rate you should save at the very least R750pm
R750 X 12 = R9000 per year
After 1st year you can add those xtra panels.
After that you need to save some of those savings for future battery replacement

We will pay R1500 a month into an account. This will be for future use on replacement and addition of equipment. I am actually excited about this whole process of getting rid of Eskom

8 minutes ago, I84RiS said:

You did not specify location. If in Cape Town you will probably be able to cover more than 85% of electricity usage in summer if you can mange the loads during the evening.

In winter this will drop to about 50% of electricity usage, you will need more panels for the Cape winter.

We are in Nelspruit. Hopefully we can reach 85% here

6 minutes ago, WannabeSolarSparky said:

If you manage your loads correctly then yes.
You can also FORCE yourself by keeping eskom switched off most of the time and only switch it on if you really need some extra power.
That's what I do now.
Those growatt spf5000 units are quite robust and should handle well managed loads quite comfortably

Can you swith Eskom off at the inverter our must you switch it off outside at the main Eskom supply? 

1 minute ago, Nature said:

We are in Nelspruit. Hopefully we can reach 85% here

Aim to get a few more panels as soon as budget allows. Get those xtra 2 panels so your cloudy days will not be too much of an issue

3 minutes ago, Nature said:

Can you swith Eskom off at the inverter our must you switch it off outside at the main Eskom supply?

You can simply switch it off at your DB board, the main breaker
Just be sure the installation is done correctly to ensure everything is still safe when eskom is switched off.
You would need to discuss with your installer as you would want the geyser to get power as well.
Most installers do not add the geyser to your essentials.

Edited March 19, 20233 yr by WannabeSolarSparky

2 minutes ago, WannabeSolarSparky said:

Aim to get a few more panels as soon as budget allows. Get those xtra 2 panels so your cloudy days will not be too much of an issue

Save in winter and add panels before our rainy season start

37 minutes ago, Nature said:

Does the solar charge the battery and carry the load without using Eskom?

Correct. I run purely Solar. The Inverter satisfies the load first and any excess goes into battery charge. And when the battery is full you normally end up frustrated not knowing what to do with the excess 😉
 

51 minutes ago, Nature said:

Are there settings that will prevent Eskom interfering with my plans 😅

Basically two options.
The off grid option as I have where you are in charge of the change over switch. i.e. you select either solar or Eskom. There won't be a grid in connection to your Inverter.
Option 2 is where you do have the Grid in connection but that is fed via a CB from your DB and you could just switch it off or set your Inverter settings so that it will only use Eskom conditionally. You will see in the manual that the Inverter has program options to prioritise the source.  SUB - solar then utility then battery, SBU - Solar the battery then utility. 
There are other fine tuning options in terms of at what SOC you wish to charge the battery from utility.
Check the manual and ask on the Forum once you get started.

1 hour ago, Nature said:

Thank you for the feedback. We are also on gas for cooking and coffee. An extra battery is not an option at this stage. I would rather consider adding 2 panels to reduce the battery charging time. This system must save us a lot of money taking into account future electricity increases. 

Didn't gas recently go up by R5/kg? I would use more electricity, especially while the sun is up.

2 hours ago, Nature said:

This is what I need.

Please explain the following to me

Does the solar charge the battery and carry the load without using Eskom?

Yes. I have 3.9kW of panels & 4.6kW inverter, so a little smaller than you on the PV side and I exceed that. 

Note

1) my loads during the night are low. This has already been mentioned. To maximise your system, do as much work as possible during the sunlit hours. 

2) I have double your battery. I can get through the night (say 17:00 to 7:00) on battery and I have some in hand.

2 hours ago, Nature said:

I don't want any Eskom during a sunny day. Are there settings that will prevent Eskom interfering with my plans 😅

They can't interfere with your system. 

You don't say where you live and who sells you electricity. Here in Johannesburg you need to buy some prepaid every 3 months. If you fail to do that, City Power stop recognising your meter. 

Also expect knocks on the door. Your drop in usage will be noticed. 

4 hours ago, Nature said:

This is what I need.

Please explain the following to me

Does the solar charge the battery and carry the load without using Eskom? I don't want any Eskom during a sunny day. Are there settings that will prevent Eskom interfering with my plans 😅

Some great replies and good use stats. The metric that is lacking in order to answer if you can manage not to use Eskom during the night time is not provided.

During the day time you are using PV for all loads. If your through the night load is also 750W from 17h00 to 07h00 in the morning you will not get through the night on your battery. Thus you either use Eskom or another R28 000 for a 2nd battery.

I guess you will generate a bit less than those from Gauteng?. 

Great stats from @zsde I just think that during March we had more PV available than during February. But yes he is doing very well to contain or eliminate using Eskom power. On bad PV days he is cutting his daily consumption to less than PV generation based on figures he has shown here. 18 Feb was one of those bad PV  days that he used only 7kWh vs around 12-13kWh on most other days.

Overall it does seem you can perhaps hit the target but for the power used during the 17h00 to 07h00 period. This period might be 2 hrs longer as little PV available 07h to 08h and also 16h to 17h. This means a 12h period of running in battery mode.

As @WannabeSolarSparky indicated get those extra panels as soon as you can. I do belief the target might be met if you can succeed in using all the PV you have on sunny days. Most members seem to have a lot of PV going wasted during a day and battery being full and not enough loads switched on.

5 hours ago, zsde said:

Today we were blessed with so much sun again. Battery was full just after nine and there was sufficient solar to start the geyser shortly after.

Geyser was at max just before 10.

Yes today without LS was also a day as perfect as one can order