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Hi There,

Can anyone comment on my below components.

Inverter - https://www.sustainable.co.za/solis-4g-12-0kw-dual-mppt-3-phase-grid-tie-inverter.html
Battery bank - https://renewables.herholdts.co.za/product/byd-10kwh-lithium-ion-48v-battery-bank-complete/
Solar Panels (x20) - https://renewables.herholdts.co.za/product/canadian-solar-72cell-310w-pv-module/
Charge Controller - https://renewables.herholdts.co.za/product/victron-bluesolar-mppt-250-100-tr/
Geyser - https://www.sustainable.co.za/gap-eco-green-200l-direct-solar-geyser.html

 

What am i going to use it for?

Always on:

  • Fridge
  • Freezer
  • Wifi router

Day Time:

  • TV
  • Computer
  • 1000W Aircon
  • Borehole (2.5kW)
  • Washing mashine
  • Iron.

Night Time

  • Lights
  • TV
  • Computer

 

Note, that this is not an entire off-grid system, it is to save power where possible. So it is grid-tied. 

I currently use around 50kWh a day, i am looking to more or less halve the usage. I will be replacing all lights with LED lights, replace my geyser and replace two additional geysers with gas geysers 

The geyser will hopefully heat up during the day. I am also going to change habbits to do as much power hungry tasks during the day.

Am i being realistic at all? and, the above mentioned equipment, are they compatible, also, am i missing any BIG ticket items that is obvious?

Edited by soic

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  • Chris Hobson
    Chris Hobson

    Hi Soic Welcome The Solis is purely a grid-tie inverter and you will not be able to run you loads from batteries.

  • Chris Hobson
    Chris Hobson

    Under those circumstances I would wire the above essential loads onto 1 phase (if possible) and then put inverter on that one phase.  

  • For price comparisons you should also try https://thepowerstore.co.za/ and don't forget this forum also has a store https://powerforum-store.co.za/ I'm a Goodwe fan... just putting it out there

  • Author

@Chris Hobson any suggestions on an inverter that will be able to run the batteries as well? that is grid-tied? or any alternative setup that will achieve my goal

Edited by soic

  • Author

@Chris Hobson I have three phases coming into my db board. if i can somehow only use one of those phases i can go with a single phase inverter. or if it is possibl to combine them.

Thing is... i have no 3 phase equipm,ent, so the three phases is not a requirement. unfortunately it is what is laid to my db board.

Sorry, i have done as much research as a can but the whole concept still eludes me :)

2 hours ago, soic said:

Note, that this is not an entire off-grid system, it is to save power where possible. So it is grid-tied.

I am assuming none of this has been purchased yet.

Then ditch the batteries, & go with a straight PV-inverter, it will have a built in MPPT so you don't need the extra CC MPPT either.

This is by far the cheapest option and bang for the buck, but when the grid goes down your lights go out.

Probably,  it's double the price if you want to go the hybrid inverter with battery route.

However the inverter you spec'd is 12kVa, you only have 6.2 kWp of panels.

On the panels, if you're limited for space you can get higher power panels, if you're not limited for space get the cheapest cost/watt panel , but buy them by the pallet for the best prices. (Normally, between 26 & 28 panels /pallet depending)

Single phase verses 3 phase have different size limitations if you want to get things signed off all legal like.

In which case, I would choose a PV inverter that's already on Cape Town's approved list as well.

 

 

 

  • Author
1 hour ago, phil.g00 said:

I am assuming none of this has been purchased yet.

Then ditch the batteries, & go with a straight PV-inverter, it will have a built in MPPT so you don't need the extra CC MPPT either.

This is by far the cheapest option and bang for the buck, but when the grid goes down your lights go out.

Probably,  it's double the price if you want to go the hybrid inverter with battery route.

However the inverter you spec'd is 12kVa, you only have 6.2 kWp of panels.

On the panels, if you're limited for space you can get higher power panels, if you're not limited for space get the cheapest cost/watt panel , but buy them by the pallet for the best prices. (Normally, between 26 & 28 panels /pallet depending)

Single phase verses 3 phase have different size limitations if you want to get things signed off all legal like.

In which case, I would choose a PV inverter that's already on Cape Town's approved list as well.

 

 

 

I have not purchased anything yet. 

I have around R150k to start off with

My immediate need is to have backup during load shedding. BUT, i need it to be scalable as i will have 200k additional funds in 7 months, and i would prefer not to re-purchase items due to scaling.

 

8 minutes ago, soic said:

Hybrid, so that when the batteries run out i can use municipal powe 

 

1 hour ago, phil.g00 said:

In which case, I would choose a PV inverter that's already on Cape Town's approved list as well.

Then your choice is Solax, Victron or Infinisolar. The Infini does come in a 3-phase unit (one of the few), 10kva, but they are over 50k to buy. I know nothing about the Solax. For Victron you'd have to buy 3 units to build a 3-phase system, but if you can get away with 3kva per phase, you can install 3 x 3kva Multiplus-II (should cost less than 40k). I assume the borehole pump you listed is 3-phase.

  • Author
6 minutes ago, plonkster said:

 

Then your choice is Solax, Victron or Infinisolar. The Infini does come in a 3-phase unit (one of the few), 10kva, but they are over 50k to buy. I know nothing about the Solax. For Victron you'd have to buy 3 units to build a 3-phase system, but if you can get away with 3kva per phase, you can install 3 x 3kva Multiplus-II (should cost less than 40k). I assume the borehole pump you listed is 3-phase.

 

nope..

i have no 3 phase appliances. 

Just now, soic said:

i have no 3 phase appliances. 

Well then you can also look at a single 5kva unit, but price-wise it's going to be pretty similar to 3 MP-II units. And then you don't have to rewire things.

  • Author
4 minutes ago, plonkster said:

Well then you can also look at a single 5kva unit, but price-wise it's going to be pretty similar to 3 MP-II units. And then you don't have to rewire things.

I can spend around 40k on a hybrid inverter and charge controller (not sure if some inverters come with a cc?)

right now i am working from 2 sites ... sustainable.co.za and herholdts.co.za. I dont always understand the accronyms, but does some inverters come with a charge controller?

1 minute ago, soic said:

I can spend around 40k on a hybrid inverter and charge controller (not sure if some inverters come with a cc?)

Hang on, I forgot about Goodwe. Victron generally ship without bundled solar chargers (aka charge controllers), but you can also look at the EasySolar inverters which bundle an MPPT.

2 minutes ago, soic said:

sustainable.co.za and herholdts.co.za

Sustainable is expensive, usually around 20% more than you can get elsewhere. For Victron, look at Current Automation, they usually have excellent pricing.Might have to contact them to get the latest price list. I heard good things (well... one good thing, they sell BYD at a good price) about herholdts...

15 minutes ago, plonkster said:

Hang on, I forgot about Goodwe. Victron generally ship without bundled solar chargers (aka charge controllers), but you can also look at the EasySolar inverters which bundle an MPPT.

Sustainable is expensive, usually around 20% more than you can get elsewhere. For Victron, look at Current Automation, they usually have excellent pricing.Might have to contact them to get the latest price list. I heard good things (well... one good thing, they sell BYD at a good price) about herholdts...

For Victron stuff I have also found CurrentAutomation to have the best prices.

 

46 minutes ago, soic said:
5 hours ago, soic said:

it is to save power where possible. So it is grid-tied. 

My immediate need is to have backup during load shedding.

You have to be very clear in your mind about you intend to achieve.

"Cutting the bill" or "having back-up power", are often at cross purposes.

All singing, all dancing system hybrid system is very expensive.

Running off batteries is not cheap either.

The most cost-effective option is probably a generator for backup, but it wont reduce the bill.

Get a generator capable of auto-starting.

A PV inverter as described above and generator for backup, satisfies both needs simplest fastest and cheapest.

The right  hybrid inverter and batteries at a later stage can still incorporate the PV inverter and the generator.

If that's the route you eventually intend to take, some brand pv inverters tend to pair better with some brand hybrid inverters, so that could also influence your buying decision now.

 

  • Author
17 minutes ago, phil.g00 said:

You have to be very clear in your mind about you intend to achieve.

"Cutting the bill" or "having back-up power", are often at cross purposes.

All singing, all dancing system hybrid system is very expensive.

Running off batteries is not cheap either.

The most cost-effective option is probably a generator for backup, but it wont reduce the bill.

Get a generator capable of auto-starting.

A PV inverter as described above and generator for backup, satisfies both needs simplest fastest and cheapest.

The right  hybrid inverter and batteries at a later stage can still incorporate the PV inverter and the generator.

If that's the route you eventually intend to take, some brand pv inverters tend to pair better with some brand hybrid inverters, so that could also influence your buying decision now.

 

I feel like i am in waaay over my head here...

From my understanding cutting the bill and having power backup is all doable by using the proper equipment. and from what i have learned so far is getting a hybrid inverter goes a long way in achieving this.

I can over generate power during the day using pv modules, and charge batteries as well as draw current directly from the solar array. When the power goes out (loadshedding) i should have battery backup.

 

 

 

Edited by soic

38 minutes ago, soic said:

From my understanding cutting the bill and having power backup is all doable by using the proper equipment. and from what i have learned so far is getting a hybrid inverter goes a long way in achieving this.

I can over generate power during the day using pv modules, and charge batteries as well as draw current directly from the solar array. When the power goes out (loadshedding) i should have battery backup.

PV inverter is cheaper, probably around 30% (capital cost) and more efficient (95%)at reducing you bill.

A hybrid inverter is less efficient because of the round trip through the batteries.

But that saving is minor compared to:

An equivalent size generator is much cheaper(capital cost) and far more capable(capital cost), with a higher running cost, but not vastly higher.

It is more capable because it can go all day, and a battery can't.

If you factored in what size battery you  need for say your 50kWh/day usage, you'd find a capable generator significantly cheaper than the price of 1 of your specified batteries.

And you'd need 5 batteries to do the same, never mind the cost of the means to charge them. There really is no contest.

The running cost of a generator will be even more comparable in the daily load-shedding scenario where you will be probably be using the grid to charge the batteries.

 

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