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Hi Guys I am new to the forum. I need some help here I am based near Alexander Bay. I am on a farmstead on the river my electriciry bill and loadshedding is killing me... my montly usage is average 62400 units of electricity per month I do a little farming but my main power consumption is my hatchery this has to run 24 hours per day I breed Austrolops and Rhode Island white chickens and a couple of quail breeds some are imported and not common in SA my main problem is power consumption and loadshedding I have lost a lot of eggs!! This is costing me a huge amount of money in losses and income... I have been following the forum for a couple of months and decided to join as a member. I have a limited budget of arround 500k I know its not a lot but thats my limit. I need a solar power solution with battery backup to save my farming opperation. I have read a lot about Sunsynk inverters and Victron inverters on the forum also the pylontech batteries. The problem I have is that Iam close to the coast and we have a lot of cloud cover through out the year and I don't want to waste my money I need a sound solution I would even consider wind power some times the wind can blow strong here I have looked at Tessup and EKalahari wind turbines I must say that the Vertical axis turbines by Ekalahari look very tempting to me. So with all this said I need some quotes on solar equipment and wind power and what would be advisable a local company in Alexander bay has quoted me for a system and they seem very expensive so good sound advice would be appreciated. I also need advice if I should try to install the system myself or do you recommend good installers. I have lots of north facing steel roof space available and my eskom power connection is three phase I run the hatchery and a borehole and basic houshold appliances my main power consumption is the hatchery my house only uses 18 units per day the rest is for the farming opperation. Thank you I am a desperate farmer..

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9 hours ago, Johannvdm said:

montly usage is average 62400 units of electricity per month

This is allot of units per month, my rough estimate is that you use about 688 units per day, if you only want to generate half of that your looking at a system that can deliver about 43A per phase. I would start looking at something like a  SMA 25000W three phase unit. I have no experience with these units but have seen them in industrial installations.

 

10 hours ago, Johannvdm said:

I also need advice if I should try to install the system myself

There is nothing wrong with installing the system yourself but you are looking at quite a big system and lots can go wrong if you have no experience. I would recommend if you got a electrical engineer involved with the design and materials used.

 

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I am also a farmer with similar usage as you.  I have gone off-grid for the sort of cost you are talking about (R350k because it was DIY), but be aware that you may need to buy at the lower end (Axpert) rather than the Victron at your budget.

Real key is whether you intend keeping the ESKOM connection (with it's massive fixed connection charge), switch to a Land Light 60A single phase (no connection charge but over R5/kWh) or drop ESKOM entirely.

For me the sensible option ended up the 60A single phase - it is essentially a hassle free generator at lower costs than running a generator.  That way you can size your batteries to keep you going overnight and run on ESKOM only during extended bad weather (I have just run through the Cape winter without using any ESKOM power at all). The batteries are the single biggest expense.

Be very careful with VAWTs.  See this blog https://scoraigwind.co.uk/2016/12/what-is-it-about-vertical-axis/

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2 hours ago, Johannvdm said:

Sorry I made a mistake there I use 1560 units per month not 62400 I was looking at the wrong numbers 

My advice would be to sit down with a good installer, work through your exact back up needs and statistics about the weather in your region. Then you get an idea about the battery bank you are looking for.

I’d say that you probably don’t need to go all out on the batteries and just get a generator for the few really bad days in the year.

Remember to take into account battery capacity degradation and DC to AC conversion losses when sizing the bank. You don’t want to go just on the rims from the get go, because your capacity might decline in a few years to the point where it doesn’t meet your needs anymore. 

PV is the cheapest item here, so see how much you can overspec it. Also don’t just go north. Try east and west also for early morning and late afternoon sun. You want to limit your reliance on batteries as much as possible.

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16 hours ago, Johannvdm said:

main power consumption is my hatchery this has to run 24 hours per day

This will require batteries for the night use, It would be best to measure the load drawn during the night to get an idea on what equipment needs to run during the night in order to get a better idea of the size batteries you will need for the hatchery.

 

17 hours ago, Johannvdm said:

I run the hatchery and a borehole

Is the borehole three phase and do you need three phase on the farm?

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On 2020/09/25 at 5:02 PM, Gerrie said:

This will require batteries for the night use, It would be best to measure the load drawn during the night to get an idea on what equipment needs to run during the night in order to get a better idea of the size batteries you will need for the hatchery.

 

Is the borehole three phase and do you need three phase on the farm?

My Household uses plus minus 18 units per day the 1.7KW Borehole pump runs For 4 to 5 hours per day depending on the season the Hatchery consumes about 1.5KW per hour but also depends on the season and weather I am also looking at expanding the opperation I use a 3 Phase compressor and have a maize grinder that also runs 3phase its cheaper to grind the maize myself. I have a couple of tools I run from time to time in my workshop welder drill press bench grinder etc and I have a old diesel generator that I can use to run that.

I can't use the Generator for the hatchery because the last time I tried that it damaged the computer controll unit and cost me a lot to have it repaired thats why I am looking at solar power to run the Hatchery and my house hold. What kind of inverters would you recommend I have been reading on the forum that the Axpert inverters are notoriously unreliable and Victron unaffordable expensive but very good.

 

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On 2020/09/25 at 11:09 AM, Calvin said:

I am also a farmer with similar usage as you.  I have gone off-grid for the sort of cost you are talking about (R350k because it was DIY), but be aware that you may need to buy at the lower end (Axpert) rather than the Victron at your budget.

Real key is whether you intend keeping the ESKOM connection (with it's massive fixed connection charge), switch to a Land Light 60A single phase (no connection charge but over R5/kWh) or drop ESKOM entirely.

For me the sensible option ended up the 60A single phase - it is essentially a hassle free generator at lower costs than running a generator.  That way you can size your batteries to keep you going overnight and run on ESKOM only during extended bad weather (I have just run through the Cape winter without using any ESKOM power at all). The batteries are the single biggest expense.

Be very careful with VAWTs.  See this blog https://scoraigwind.co.uk/2016/12/what-is-it-about-vertical-axis/

Thank you for the great advice I think maybe I should try to follow the self install route my eskom 3 phase line rental is R1800 +- per month the cost is a factor and the Ideal for me would be to be almost off grid I will contact eskom to change my connection to single phase my main problem with them is how unreliable their service is I have had days where they have been down for up to 48 hours due to "line faults" and they go down atleast once a week never mind loadshedding it is very frustrating and I loose a lot of eggs and chicks due to that. Thanks for the heads up on the VWAT.

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1 hour ago, Johannvdm said:

My Household uses plus minus 18 units per day the 1.7KW Borehole pump runs For 4 to 5 hours per day depending on the season the Hatchery consumes about 1.5KW per hour but also depends on the season and weather I am also looking at expanding the opperation I use a 3 Phase compressor and have a maize grinder that also runs 3phase its cheaper to grind the maize myself. I have a couple of tools I run from time to time in my workshop welder drill press bench grinder etc and I have a old diesel generator that I can use to run that.

I can't use the Generator for the hatchery because the last time I tried that it damaged the computer controll unit and cost me a lot to have it repaired thats why I am looking at solar power to run the Hatchery and my house hold. What kind of inverters would you recommend I have been reading on the forum that the Axpert inverters are notoriously unreliable and Victron unaffordable expensive but very good.

 

There are a couple of solutions available my opinion is a little baised when it comes to inverters. Axpert clone inverters are definately not what I would recommend for your application. Lets face it your inverter is the corner stone of your whole solar power system so choosing the correct inverter is very important. Future expandability also plays a major factor. So before we look at solar panels and batteries I would recommend you look at the following options The Victron Multiplus series inverters are very good but a comple 3 phase package will cost the price of a small farm they work very well with Grid tied inverters like Fronius and Solis they are also compatible with most batteries on the market. Configuration and setup gets complicated and you require a lot of addons to make the system work according to your needs. I would recommend you get advice from the Victron experts on the forum if you want to go that route. Your next option would be Sunsynk or Deye inverter range also a very good product packed with features out of the two brands I would personally go with Sunsynk they have excellent after sales service and backup definately an up and comming product whats nice about these inverters is that they are all in one device they can supply solar power to the grid side and the off grid side of the inverter they support all major battery brands comes with a 5 year warranty etc If you plan to self install then looking at this product would be a good choice it is easy and simple to install and setup. You can also run up to 10 of them in parallel in single or three phase configuration.

However your cheapest route would be to change your 3 phase eskom connection to a single phase connection. This will reduce the cost of the inverters considerably. Any three phase equipment you need to run can be run with single to three phase variable speed drives this means you can power three phase motors with a single phase power point. 

I hope this gives you more clarity.

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2 hours ago, Johannvdm said:

eskom 3 phase line rental is R1800 +- per month the cost is a factor and the Ideal for me would be to be almost off grid

What Calvin has done to change to a single phase connection might be a good way of saving some monthly charges. That single phase could act as backup when there is bad weather and also run your three phase equipment if you install a separate three phase inverter purely for the electric motors. That would enable you to install a single phase solar system that you can expand on later.

The only thing to look out for is if you decide to use the Eskom single phase and convert it to three phase, is the KW size of your equipment, as I think the inverters to three phase only go up to 7KW. So motors bigger than 7KW becomes a problem to run. Then also the saving might be reduced again due to the high Eskom rate but I’m sure as a backup lifeline Eskom is definitely still worth having.

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1 hour ago, Gerrie said:

I think the inverters to three phase only go up to 7KW

This may not be quite right - my understanding is that most (all?) big inverters (> 8kW) are 3 phase.  Certainly all the ones I could find with a quick Google....

Most smaller inverters can also be paralleled in 3-phase configurations.

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4 hours ago, Johannvdm said:

Axpert inverters are notoriously unreliable

I ended up using the "cheap-and-nasty" Axperts.  

My thinking was essentially the same as in RAID disk arrays - I did not want to be dependent on a single 15 or 20kW inverter.  I bought three 5kW Axperts and have a fourth as spare - still much cheaper then the blue option.😂

BUT - the Axperts are very problematic. OK but not first-class hardware, poor firmware and unbelievably poor support.  Generally you need external software to manage them effectively - If you want a hands-off solution, I would not recommend them.

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2 hours ago, Calvin said:

my understanding is that most (all?) big inverters (> 8kW) are 3 phase.

I think we are looking at different inverters, are you looking only at solar inverter and I am also mentioning frequency drive inverter that is used to make eskom single phase to three phase for electric 3phase motors. I suggested installing a single phase solar inverter to run all loads except three phase loads, and then also install a frequency drive inverter that makes three phase from Eskom single phase to run the borehole maize grinder and compressor. 

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What is your average downtime re load-shedding, 4-5 hrs, how often, every day or once a month ?

What is minimum time that you your incubators can stand for with no power?

You need the above for accurate calcs to get battery capacity.

It looks like you're using about 2kW/hr so for a 5 hr load-shedding time (and no sun) you'll need 12kW battery capacity (80% DoD), 4 X US3000 Pylontechs will give you 14kW @ about R90K (R22k each).

If you want to go 10 hrs, just double battery capacity.

PV required: In Alexander bay you're getting an average of 5.4kWhr/kWp installed per day as per the attached chart, so taking 80% max production due to cloud etc you will probably require in the region of 10kW of panel to give you a comfortable 25kW during the day time and then enough power, +- 15kW to recharge your batteries as well at the same time.

10kW of panel will cost about R70K, panels only, you still need fittings etc, about another 35k.

Not sure how 3 phase inverters fit into the picture..

So without inverters and installation costs you are talking about R200K minimum...(6 hr load shedding time at night).

A rough calc but enough to give you some idea of costs...

If anybody else can improve on these rough calcs please do ...

 

 

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