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1 hour ago, Jaco de Jongh said:

Please share the savings? Sure we are going to love that figure? 

When we first looked they peaking at  about 380 kWh a day and averaging about R20k/month on direct electricity costs. Eskom has additional charges that take the bill to R25k/month. There was no measurement Feb/Mar due to over estimate up until Jan. April's bill skyrocketed to R50k  May and Jun were roughly  R30k (normal consumption) and now we have a bill for just over R8k. The lodges have been full so our initial estimates my be out but is looks like a saving of about R10-12k per month and the total cost excl. Vat was R290k. Probably pay for itself in 3 years.

 

  • Author
13 hours ago, Jaco de Jongh said:

Thanks Chris, its just so rewarding when you see the savings... 

I was starting to worry a bit as the bill was just not coming down but Eskom plays musical chairs with billing sometimes it is accurate and at times I think they seek out people for their good looks rather than their ability to read a meter.

Reminds me of the joke of a farmer saddling up a horse for a  city boy to ride. The farmer remarks that the horse doesn't look so good. The city boy is a accomplished horsemen often riding over weekends. He stands back to admire the steed and  decided  the farmer doesn't know what he is talking about. The city boy mounts up and canters across the field and promptly crashes into the split pole fence. He is furious and comes back and admonishes the farmer for not telling him the horse was blind. "I told you the horse does not look so good" was farmer's matter of fact reply.

  • 4 weeks later...
  • Author

The client and his business partner want both of their homes switched to solar. The proof of the pudding is in the eating. I will install two 3 phase effergy meters just so I know what I am dealing with. The one farmstead has an industrial laundry servicing surrounding lodges which is about as good a load as one could ask for to run off solar as it operates during the day.

1 hour ago, Chris Hobson said:

The client and his business partner want both of their homes switched to solar. The proof of the pudding is in the eating. I will install two 3 phase effergy meters just so I know what I am dealing with. The one farmstead has an industrial laundry servicing surrounding lodges which is about as good a load as one could ask for to run off solar as it operates during the day.

I tried to send you a message, but I get ERROR 15, site assess denied error when I try to send you a message?

On 2018/08/23 at 6:20 PM, Chris Hobson said:

he lodges have been full so our initial estimates my be out but is looks like a saving of about R10-12k per month and the total cost excl. Vat was R290k. Probably pay for itself in 3 years.

Here was my message:

I work on a farm where the most of our power consumption is in the day, the farm also has a nursery and farm stall on it, so it does happen quite often in the summer months when it gets really hot (Like yesterday) that we trip the 150A breaker.

We have had one guy here to give us a quote, I can't remember exactly for how much KW of installed power it was, but the quote had WAAAY too many 0's in it, my question is, how much installed power did you provide your client with for that R290K? Because you say his power bill was around R30K, and ours is around R33K, so its pretty close?

Just a rock in the bush (klip in die bos) ... if you are on a farm, no regs as we have in the cities, look at 2nd hand Axperts. There may be some coming up for sale. @ebrsa coming to mind IF that is still a though he ponders on.

16 minutes ago, The Terrible Triplett said:

Just a rock in the bush (klip in die bos) ... if you are on a farm, no regs as we have in the cities, look at 2nd hand Axperts. There may be some coming up for sale. @ebrsa coming to mind IF that is still a though he ponders on.

The sad thing is, a Axpert (Well and depending on which model of Axpert) only has 5Kva of power in that MPPT so without buying 4+ it would be a little too small also I don't need battery backup, I am more interested in say a 20-40Kva GTI solution, we have a 180Kva generator that kicks in to save the day usually if the power falls over.

Edited by PJJ

8 minutes ago, PJJ said:

20-40Kva GTI solution

Next level.

You can add 2-4 x 10kw Quattro's in parallel = 20-40kva - will have to shop very hard to keep them prices right.

They can handle panels, Eskom and gennie all in one.

So an idea to trigger more ideas, instead of bunch of MPPT's, get a Fronius grid tied inverter.
Fronius is not connected to the grid, no, but to the Quattro output, i.e. before the loads.
When the grid power to the Quattro's go off, the grid tied (or is it now Quattro tied) Fronius inverter/s still power the loads from panels.
If there is insufficient solar, the Quattro's supplement from batteries.
And at a set SOC, only then the Quattro's auto start the gennie.

 

Ps. The Axpert potential idea was just a "klip in die bos" as we don't always think of opportunities presenting themselves.

5 minutes ago, The Terrible Triplett said:

Next level.

You can add 2-4 x 10kw Quattro's in parallel = 20-40kva - will have to shop very hard to keep them prices right.

They can handle panels, Eskom and gennie all in one.

So an idea to trigger more ideas, instead of bunch of MPPT's, get a Fronius grid tied inverter.
Fronius is not connected to the grid, no, but to the Quattro output, i.e. before the loads.
When the grid power to the Quattro's go off, the grid tied (or is it now Quattro tied) Fronius inverter/s still power the loads from panels.
If there is insufficient solar, the Quattro's supplement from batteries.
And at a set SOC, only then the Quattro's auto start the gennie.

 

Ps. The Axpert potential idea was just a "klip in die bos" as we don't always think of opportunities presenting themselves.

We will definitely not be adding batteries, the required discharge capacity would simply make it not feasible, on a 48V bank we could* draw 33000W / 48V = 687A!  

My thinking here is, we have a ATS now with the genie, maybe a Fronius after the grid/genie would do the trick?

Because even if the grid drops away, the genie would kick in, simulating a grid? and the PV would then also provide some relief for the genie and keep on marching on.

And in normal circumstances if the grid is there the Fronius just helps chip in as much as it can and takes the difference from the grid.

7 minutes ago, PJJ said:

Because even if the grid drops away, the genie would kick in, simulating a grid?

Not sure if the gennie will be stable enough. @plonkster must weight in here.

7 minutes ago, PJJ said:

48V bank we could* draw 33000W / 48V = 687A! 

No, I would go the smallest bank possible, as it is basically a connection, that is IF the more clever ones agree it could work seeing as the panels are on the Fronius, not on the batteries, and you can limit the charging on the Quattro. Plonkster can weight in here too.

Note: Just ideas!
Maybe it is not the solution, maybe it is ... let the juices flow. Other will give more ideas too. Me I share the blue ideas. :-) 

Edited by Guest

8 minutes ago, PJJ said:

draw 33000W / 48V = 687A!  

Remember, some loads you keep on the circuit of the Quattro that goes off, if the grid fails, that is till the gennie starts. 

That way you keep sensitive going on a small bank, waiting for the gennie, not the entire farm.

Batteries only should come into play if there is insufficient power from the Fronius, and only for a short while till gennie starts, or if gennie does not start, then a very small select load is running.

14 minutes ago, PJJ said:

Because even if the grid drops away, the genie would kick in, simulating a grid? and the PV would then also provide some relief for the genie and keep on marching on.

Just keep in mind that the generator typically has a optimum "burn rate" somewhere around 80% of its capacity, where it's fuel use for the generated power is optimum. Running a generator to "simulate" a grid while a PV inverter carries all the loads is not going to be cost effective, but using the PV-inverter to carry the top 20% to get the generator into that optimum window will be. This issue is rather a lot more complex :-)

Also PV inverters will disconnect if they see anything that looks like an islanding event (eg large load turning on/off changing the generator engine speed for a short time), so you still have to design it such that the generator can carry everything while the PV-inverter reconnects. Also means you need a nice bulky Diesel generator with a clean output, not a light petrol that's all over the place.

But the idea of using a generator with the PV-inverter just offsetting 20% fuel cost at the top... that idea seems golden to me.

  • Author
4 hours ago, PJJ said:

I tried to send you a message, but I get ERROR 15, site assess denied error when I try to send you a message?

Here was my message:

I work on a farm where the most of our power consumption is in the day, the farm also has a nursery and farm stall on it, so it does happen quite often in the summer months when it gets really hot (Like yesterday) that we trip the 150A breaker.

We have had one guy here to give us a quote, I can't remember exactly for how much KW of installed power it was, but the quote had WAAAY too many 0's in it, my question is, how much installed power did you provide your client with for that R290K? Because you say his power bill was around R30K, and ours is around R33K, so its pretty close?

It is a 36kW inverter with 25kW of Tier 1  panels in a East West array optimised for self consumption - room for expansion.

Amakhala.jpg.0df5c413a66a28ba8d6f6a4ad20f72f8.jpg

Sorry I don't have many photos of the install I will be back in the area beginning of October and I'll take more photos.

  • Author
3 hours ago, The Terrible Triplett said:

Just a rock in the bush (klip in die bos) ... if you are on a farm, no regs as we have in the cities, look at 2nd hand Axperts. There may be some coming up for sale. @ebrsa coming to mind IF that is still a though he ponders on.

I am not going to parallel 9 Axperts -  two was enough hassle. Imagine 9 combiner boxes :o plus at this sort of level of consumption your batteries would need to be serious  (About ½ a bar of Pylontechs). No if you want ROI go GTI.  The inverter has 4 MPPTs and at the moment I have one string per MPPT. If we add more panels NE/NW then strings with the same orientation will end up on the same MPPT.

1 hour ago, Chris Hobson said:

I am not going to parallel 9 Axperts - ...

Nor would I. :P

4 hours ago, The Terrible Triplett said:

Ps. The Axpert potential idea was just a "klip in die bos" as we don't always think of opportunities presenting themselves.

Open thought for anyone thinking of upgrading / starting new. 

Maybe someone else sees the klip coming and jumps.

;)

  • 3 weeks later...
  • Author

panels.thumb.jpg.9160b37c34ce6c6425790cbc14448c24.jpg

inverter.thumb.jpg.d8c0403174b3b022d70dd76a60e62837.jpg

That thick orange cable is a 25mm2 four core trailing cable. (UV resistant, oil resistant etc.) It is not armored so cannot be buried but is infinitely superior to work with compared to an armored cable. Grid limiter and GTI connection is 75m away at the Eskom box. Had an Eskom inspection and apparently passed with the proviso that the labeling is completed and the fence is up. They did however not have any major concerns - Sjoe! Inverter is IP65 but I thought a bit of shade was in order.

1 hour ago, Chris Hobson said:

panels.thumb.jpg.9160b37c34ce6c6425790cbc14448c24.jpg

inverter.thumb.jpg.d8c0403174b3b022d70dd76a60e62837.jpg

That thick orange cable is a 25mm2 four core trailing cable. (UV resistant, oil resistant etc.) It is not armored so cannot be buried but is infinitely superior to work with compared to an armored cable. Grid limiter and GTI connection is 75m away at the Eskom box. Had an Eskom inspection and apparently passed with the proviso that the labeling is completed and the fence is up. They did however not have any major concerns - Sjoe! Inverter is IP65 but I thought a bit of shade was in order.

From the shadows on all the pictures as well as the piece of frame to the right of the electrical box, this seems like an East West orientation?        Dont worry, see the picture above shows it. Scanning again. 

Do I understand this correctly, you have only connected the supply to the Inverted and you are only feeding back into the grid, No load connected to the output of the inverter?

  • Author
1 hour ago, Jaco de Jongh said:

From the shadows on all the pictures as well as the piece of frame to the right of the electrical box, this seems like an East West orientation?        Dont worry, see the picture above shows it. Scanning again. 

Do I understand this correctly, you have only connected the supply to the Inverted and you are only feeding back into the grid, No load connected to the output of the inverter?

Grid Tie Inverters (GTIs) or String inverters as they are sometimes called don't have an input and output. They have a grid connection from which they get frequency and voltage from the grid and they copy this and match it with their output along the same cables that they get their "input". If you imagine  cables running  between grid and your load (or 3 cables in a 3P system) then the GTI Ts into these cables  there is no input or output just a grid connection. Under these circumstances you need hardware and software to prevent back feeding into the grid.

Load is hopefully predominantly solar but late afternoon and early morning it is a mixture of grid and solar.

1 hour ago, Chris Hobson said:

Grid Tie Inverters (GTIs) or String inverters as they are sometimes called don't have an input and output.

So we are actually wrong when we refer to a Hybrid as a Grid tie inverter? 

1 hour ago, Chris Hobson said:

They have a grid connection from which they get frequency and voltage from the grid and they copy this and match it with their output along the same cables that they get their "input".

Isn't this exactly the same as feeding back into the grid? And if it is, i dont fully understand the following statement...

 

1 hour ago, Chris Hobson said:

Under these circumstances you need hardware and software to prevent back feeding into the grid.

Are you referring to prevent it from feeding back in the case of a power failure? 

19 minutes ago, Jaco de Jongh said:

1 - So we are actually wrong when we refer to a Hybrid as a Grid tie inverter? 

2 - Isn't this exactly the same as feeding back into the grid? And if it is, i dont fully understand the following statement...

3 - Are you referring to prevent it from feeding back in the case of a power failure? 

1 - GTI = Grid Tied Inverter

2 - Jip.

3 - Therein the regulations. :-) 

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