Starting the process to go "off-grid"

[xrapidx]

If I were to start going off-grid - with the final stage of being completely off-grid, would it be possible to buy one inverter, one set of batteries for said inverter, and one set of solar panels to keep the batteries charging. Powering just the circuits that can be off the inverter.

...then... add "modules" as time goes along?

The initial goal being to "survive" load shedding.

(currently use between 30-40kw a day, with geyser and pool)

 

[Sinbad]

If I were to start going off-grid - with the final stage of being completely off-grid, would it be possible to buy one inverter, one set of batteries for said inverter, and one set of solar panels to keep the batteries charging. Powering just the circuits that can be off the inverter.

...then... add "modules" as time goes along?

The initial goal being to "survive" load shedding.

(currently use between 30-40kw a day, with geyser and pool)

For some inverters, yes you can. I know the Victrons can be stacked in parallel, up to 3 units, provided they're the same model. Batteries would be a bit more complex, as you'd then be mixing older and newer batteries, not sure how well that would work out. Panels you can add, with additional MPPTs as needed as well.

I'd strongly suggest though that your first steps be to optimise your usage. To go fully off grid for 40kwh a day will cost you 600k+, and then you'd still be fked if the sun didn't shine for 2 days.

 

[xrapidx]

For some inverters, yes you can. I know the Victrons can be stacked in parallel, up to 3 units, provided they're the same model. Batteries would be a bit more complex, as you'd then be mixing older and newer batteries, not sure how well that would work out. Panels you can add, with additional MPPTs as needed as well.

I'd strongly suggest though that your first steps be to optimise your usage. To go fully off grid for 40kwh a day will cost you 600k+, and then you'd still be fked if the sun didn't shine for 2 days.

Surely the batteries are per inverter? So mixing won't be a problem - or is that not how it works?

You can probably bring the 40kwh down to 25kwh without the pool and geyser... not actually sure how else to reduce usage, all lights are led - all appliances are "new" - stove is gas (oven electric).

 

[Cius]

Not a good idea to mix old and new batteries from what I have heard. However, starting with a good inverter seems to be the right approach. From my research first no brainer step is solar geyser or gas geyser depending on your preference. A solar geyser will generally pay itself off quickly and massively reduce your power pull

Then get a decent inverter for the end goal, not the short term. So if you think you will need max 4KW get an inverter to cover that, and from there it is more scalable. The panels can be added piecemeal anytime. The batteries should be replaced together but you could for instance start off with cheaper batteries that may last 3 to 5 years with a plan to upgrade to better ones later.

Personally my approach will be as follows:
Solar Geyser this april.
Save up to the point where I can buy my final inverter and enough batteries to last 12 hours charging them off the grid when power is up.
Finally solar panels can be added to charge batteries.

This approach will mean I avoid load shedding easier faster but I have heard of others who preferred to either go with panels first, or a few panels and a small battery set up to cover TV and internet to get the savings going earlier and then the savings are used to scale the solution up. Like I said though, I don't think batteries are very scalable and its best to use the same and replace at the same time.

 

[Sinbad]

Surely the batteries are per inverter? So mixing won't be a problem - or is that not how it works?

I'm not sure to be honest.
My system has a DC bus side (where batteries, MPPTs and Inverter/Charger interfaces are) and AC side (grid, loads). Not sure it caters for multiple DC buses - eg, how would an MPPT on one DC bus charge batteries on a different DC bus? Unless the power is inverted and then rectified back to DC by a different inverter/charger to charge those specific batteries?

Unless you used a PV inverter on the AC side, I guess, and only charged via the inverters and not through an MPPT.

 

[xrapidx]

Geyser I'll deal with when it blows again... the idea currently is to get through load-shedding, and expand from there. So geyser isn't really a concern.

It would be great if I can go from 2-4 hours a day without Eskom - to 4-8, etc, and grow the system - instead of putting down thousands upfront.

 

[Sinbad]

Geyser I'll deal with when it blows again... the idea currently is to get through load-shedding, and expand from there. So geyser isn't really a concern.

It would be great if I can go from 2-4 hours a day without Eskom - to 4-8, etc, and grow the system - instead of putting down thousands upfront.

4 hours @ 1kw average draw = minimum 4kwh of batteries. Your average is closer to 2, so 8kwh of batteries. That's already close to 80k worth of lithium...
You'll want an inverter whose passthrough current is at least 60 amps, else you can't wire the whole house to run off it and you'll need to partition your DB.

You're going to be putting down thousands.

 

[xrapidx]

Need to finish writing my own power monitor - to get more accurate usage stats off the prepaid box.

 

[Former member 61586]

OP. I know a guy that can take you off grid for more or less R300k. And he only sells what I think is good quality stuff. Victron and so forth. Drop me a PM for his contact info. Cheapest (by an absolute country mile) and more honest (again by an abosolute country mile) than any other shark in the renewable energy industry I have dealt with.

 

[xrapidx]

OP. I know a guy that can take you off grid for more or less R300k. And he only sells what I think is good quality stuff. Victron and so forth. Drop me a PM for his contact info. Cheapest (by an absolute country mile) and more honest (again by an abosolute country mile) than any other shark in the renewable energy industry I have dealt with.

Will do.

 

[Sinbad]

OP. I know a guy that can take you off grid for more or less R300k. And he only sells what I think is good quality stuff. Victron and so forth. Drop me a PM for his contact info. Cheapest (by an absolute country mile) and more honest (again by an abosolute country mile) than any other shark in the renewable energy industry I have dealt with.

Not a chance. 10kwh of BYD lithium is at least 80k, and OP needs min 40kwh to go off grid.

Min 40kwh of solar generation as well means at least 20x 330w panels - and probably more. That's 40k there, and another 10-18k for MPPTs to drive those.
And that's before an inverter and control unit.

 

[xrapidx]

Just realised I can use the prepaid purchases, we use roughly 1000kwh a month. So substract geyser and pool, thats around 20kwh a day.

 

[xrapidx]

Not a chance. 10kwh of BYD lithium is at least 80k, and OP needs min 40kwh to go off grid.

Min 40kwh of solar generation as well means at least 20x 330w panels - and probably more. That's 40k there, and another 10-18k for MPPTs to drive those.
And that's before an inverter and control unit.

Remember, that's with the geyser and pool - which need to be excluded from the equation - they're on their own circuits and will be dealt with separately.

 

[Sinbad]

Remember, that's with the geyser and pool - which need to be excluded from the equation - they're on their own circuits and will be dealt with separately.

"off grid" has a specific meaning though....

 

[xrapidx]

"off grid" has a specific meaning though....

Exactly, but again - the geyser and pool pump will be dealt with separately. They will still be off-grid.

 

[Neuk_]

For some inverters, yes you can. I know the Victrons can be stacked in parallel, up to 3 units, provided they're the same model. Batteries would be a bit more complex, as you'd then be mixing older and newer batteries, not sure how well that would work out. Panels you can add, with additional MPPTs as needed as well.

I'd strongly suggest though that your first steps be to optimise your usage. To go fully off grid for 40kwh a day will cost you 600k+, and then you'd still be fked if the sun didn't shine for 2 days.

I understand this to be 6 run in parallel, or is that only for the smaller kVa units?

Virtually unlimited power thanks to parallel operation

Up to 6 Multis can operate in parallel to achieve higher power output. Three phase or split phase operation is also possible. Please check our datasheets to see which models have paralleling, three phase and split phase capabilities.

From here...

MultiPlus | Victron Energy

The MultiPlus, as the name suggests, is a combined inverter and charger in one elegant package. Learn more about the MultiPlus models.

www.victronenergy.com

 

[Sinbad]

I understand this to be 6 run in parallel, or is that only for the smaller kVa units?




From here...

MultiPlus | Victron Energy

The MultiPlus, as the name suggests, is a combined inverter and charger in one elegant package. Learn more about the MultiPlus models.

www.victronenergy.com

You are right - apologies.