Upgradable Home Office Configuration?

[fredhen]

Hello everyone,

Thank you for everyone's contributions on this forum. I have really enjoyed reading up on everything and clearly don't know enough yet just yet. Before finding this forum I thought it was as easy as buying an inverter, some panels and batteries and there you go. 

I would appreciate some help in speccing my solar build as I would like to get an idea of costs and will then get an idea of how much I need to save to get it (I read somewhere in the forum that rule #1 is not to borrow to get solar)

I will be working from my home office for an overseas company, but I will be working there for a couple of months first, so I thought that I could start saving and then start once I am back.
This all started with me looking into a solution that will keep the power on during load shedding or power outages as trying to explain Eskom will not be easy an easy task and most likely not accepted as an excuse for not being able to work.

I first thought about getting something small like this just to keep working (which I may still do until everything is up and running) if there are any issues, but as I will be at home I have decided to rather get something with solar in order to bring down some of the costs during the day. I read here on the forum that buying small and then upgrading inverter & batteries ends up costing you more, so I thought that I would ask for some help here to help me get an idea of what I should be looking at to start with which should then easily be upgradable (more like adding more batteries & panels) instead of going for a proper 1kVA inverter with a bit of solar and cheap batteries only needing to get a bigger inverter and better batteries a year or two later when I decide to run more off it.

What I am looking for:

The idea is not to go off the grid. This is to keep me connected whilst working should there be any issues, but to also get some eventual savings by using solar during the day
An inverter that is able to use solar during the day, but able to pull any additional power required from the grid. I may be wrong, but I read that some inverters can't add from the grid, so it will completely switch over to the grid which won't work for me as I will start with a small solar setup before adding on and would like to power as much as possible from solar during the day.
Start small with only the required solar panels and batteries to be able to run the home office and fridge off solar with a battery backup for when there are grid issues issues, but with the ability to add more panels and batteries (Basically run my 1 or 2 computers, ~5 monitors, router, fridge and a few lights during an outage from solar / batteries) I don't mind manually switching off non essentials at first before getting more solar panels and/or more batteries.
As this is for running a home office before it is for saving money I won't be buying a solar geyser / heat pump just yet, so I would like to be able to connect the geyser and have it work during the day from mainly PV (Although I will have to set the timer to also start early in the morning for the wife) I don't mind replacing the element with titanium should the new house have an older element.

As we will be going to a bigger house I don't have an idea of exactly how big to go, but the idea here is to have something for 10+ years which means it will hopefully not just be the 2 of us anymore after a couple of years. 

What I would like to have running off the inverter / solar with grid when not enough PV generation:
 * Home Office
 * Fridge
 * Geyser
 * All other normal appliances

What I would prefer running off the inverter / solar, but wouldn't mind running off the grid:
 * Oven
 * Washing macines

Is this something that is possible and do you have any recommendations as to the inverter (I don't have a prefernce as most of you seem to have), batteries (size and type obviously compatible with the inerter) as well as solar? Keeping in mind that I would like to start small and add some more panels and maybe batteries at a later stage.

I believe that a 5kVA inverter should be able to manage?
 * I was also thinking of running the batteries with something small like a 10/20% DOD to actually use them as outages won't happen often, but I would like to change that to 40/50 myself should there be an outage and I'm not getting enough from the solar panels.
What size solar panels and batteries should I be looking at (I will work 8-5, but may need to work later every now and then, but not that often, so the idea would be to have a backup from 8-5 for home office & fridge as a start from the solar panels and batteries)

I know this is an extremely long post, my apologies, but I thought I'd add as much information as possible.

Thanks in advance,
Fred

Edited July 14, 2018 by fredhen

[Guest]

Welcome Fredhen. We'll sort you promptly. :-)

4 hours ago, fredhen said:

... something small like this ...

Unless they changed it, those Mecer inverters are pretty loud ito the fan. Cyberpower UPS are really quiet. Fan only on when needed.

Correct, solar is a tough ROI, sums have been done, doing it on credit, makes it even worse.

Good idea to start with a UPS!!!
Focus on the right battery bank for the loads, for that is one of the most expensive parts of going solar.
O, and do get a BMV Battery Monitor and cable WITH the bank.

After a while, once all is settled, you see where you are going, now get a separate MPPT (larger than you need, trust me) with solar panels matching the battery bank charging with the load. 

Why? With the MPPT and panels, you start charging the batteries so that you can use the UPS for longer hours, and not using Eskom to charge the batteries. UPS is a inverter.
Now, the UPS inverter will fail, so buy a 2nd hand one for like R1000, for they are not designed to run day in and day out.
Get some ROI out of it before it goes.

At the time of the UPS popping, you have the battery bank properly specced, panels are in place and MPPT (with loads more capacity), now you buy a decent solar inverter.

Cost nicely spread over time, as you learn, AND you solved your immediate worry of Eskom failures.

 

Next thought. The moment you start talking things like oven / hairdryers / kettle in the same sentence as solar, you are looking at bigger inverter/s to handle the loads, for people will switch more on than the inverter can handle, and your computers go down. :-) 

Now take a oven, when is it mostly used? Evenings right? Hairdryers early mornings. Lights are evenings.
Think of when the loads are mostly used for if not in the ideal solar times, then batteries are required ... and Eskom is cheaper than batteries.
Plus, the big loads mentioned require bigger inverter/s. From 5kva to 10 kva - this roller coaster can blow your hair back if you don't reign it in. ;-) 

So my thinking with my system was take all loads that are below 1000w, put that on solar, rest stays on Eskom.
These loads in my case are, guess what, home office. :-) 
So morning till evening all the office stuff is on solar, sometimes I add more loads, other times I remove loads. Sometimes in summer I leave stuff on solar 24/7. Winter in Cpt, tough on solar.

For Eskom failures, I have Trojan T105RE batteries, which only powers the most important equipment, in case we need many hours of use.

The loads costing you money are the ones that are on 24/7/365. Find them.
My biggest saving, switched all loads off when everyone sleeps.

 

How does the above sound to you?

[fredhen]

Hi @The Terrible Triplett

Thanks so much for the reply!

1 hour ago, The Terrible Triplett said:

Unless they changed it, those Mecer inverters are pretty loud ito the fan. Cyberpower UPS are really quiet. Fan only on when needed.
...
Good idea to start with a UPS!!!

Why thank you. Like I mentioned, number 1 is to prevent an outage, so I thought about a cheap UPS that will do the job whilst I get everything else up and running.
They did change it then. The spec sheet that I was looking at mentioned that the fan is only on when the batteries are charging. That's the old LOBO apparantly. These ones have an intelligent fan, but I'm not fixed on anything, so I'll have a look at the Cyberpower UPS.

2 hours ago, The Terrible Triplett said:

Focus on the right battery bank for the loads, for that is one of the most expensive parts of going solar.
O, and do get a BMV Battery Monitor and cable WITH the bank.

So this is part of my struggle. What do I go with battery wise for the UPS keeping in mind that I would like to use them with the bigger inverter & MPPT when moving the rest of the house over? (See one of my last comments) I see the spec sheet of the Mecer UPS refers to Rechargeable lead-acid battery, Deep discharge battery as the acceptable battery type.

2 hours ago, The Terrible Triplett said:

After a while, once all is settled, you see where you are going, now get a separate MPPT (larger than you need, trust me) with solar panels matching the battery bank charging with the load. 

Why? With the MPPT and panels, you start charging the batteries so that you can use the UPS for longer hours, and not using Eskom to charge the batteries. UPS is a inverter.
Now, the UPS inverter will fail, so buy a 2nd hand one for like R1000, for they are not designed to run day in and day out.
Get some ROI out of it before it goes.

With using the UPS for longer I am assuming you mean disconnecting it from the wall. As far as I know the UPS' will only switch to battery power when the grid is not available.
One thing I was also looking at was the solar charger that you can get along with the Mecer UPS although it seems that the inverter will then still use the batteries while solar power charges them as you go instead of converting the solar directly. Although I'm guessing that the same applies with an MPPT?
It's actually at this point that I would consider getting an inverter & MPPT to start running off solar instead of batteries that are constantly being charged.
Thoughts?

2 hours ago, The Terrible Triplett said:

At the time of the UPS popping, you have the battery bank properly specced, panels are in place and MPPT (with loads more capacity), now you buy a decent solar inverter.

Cost nicely spread over time, as you learn, AND you solved your immediate worry of Eskom failures.

I guess the spreading of costs is a reason to delay getting an inverter & MPPT, but I need to go overseas for ~5 months and start house buying once back, so I should have enough saved up to maybe pull that trigger earlier by then. (My thinking is the battery use as above)

2 hours ago, The Terrible Triplett said:

Next thought. The moment you start talking things like oven / hairdryers / kettle in the same sentence as solar, you are looking at bigger inverter/s to handle the loads, for people will switch more on than the inverter can handle, and your computers go down. :-) 

Now take a oven, when is it mostly used? Evenings right? Hairdryers early mornings. Lights are evenings.
Think of when the loads are mostly used for if not in the ideal solar times, then batteries are required ... and Eskom is cheaper than batteries.
Plus, the big loads mentioned require bigger inverter/s. From 5kva to 10 kva - this roller coaster can blow your hair back if you don't reign it in. ;-)

I can safely say that once you gas for your stove you never go back, so the electric kettle barely gets used.
I don't think I will ever see the need for an oven on this solution. As you said, it's used in the evenings, so it'll just suck the life out of the batteries especially if I only really want to use the batteries to . I actually didn't think about the time of day, so no, the oven goes on the grid and klaar. (Reining it in ) The gas stove can be lit with matches if there's a power issue and the ignition is down.
The hair dryer on the other hand is another issue. Yes, it'll be used in the mornings, but by then there won't be battery left, so it should then just be from the grid in any case, although I am thinking that I will end up with a bigger inverter just for that as everything else should be able to run off 3kVA?

2 hours ago, The Terrible Triplett said:

So my thinking with my system was take all loads that are below 1000w, put that on solar, rest stays on Eskom.
These loads in my case are, guess what, home office. :-) 
So morning till evening all the office stuff is on solar, sometimes I add more loads, other times I remove loads. Sometimes in summer I leave stuff on solar 24/7. Winter in Cpt, tough on solar.

You're starting to talk some sense into my wallet. The wife added the save the planet part, so in our case I would like to maybe have most of the house running off solar during the day (Home office, fridge, lights & other small appliances) with bigger ones off the grid (Geyser, oven, washing machines & hair dryer)

I'm guessing that I'll be safe on 3kVA then? 

• I know the split is bit of a dream especially splitting the fridge & washing machines as I know most of the times they are wired to the same plugs switch on the DB, but I guess I won't know until we find the house

2 hours ago, The Terrible Triplett said:

For Eskom failures, I have Trojan T105RE batteries, which only powers the most important equipment, in case we need many hours of use.

Back to the batteries question. I have NO idea what to do battery wise. The main thing is to have the home office & fridge running off battery backup should there be no grid available. I don't mind switching off other things that's not needed when there is an outage and I'm at home.

2 hours ago, The Terrible Triplett said:

The loads costing you money are the ones that are on 24/7/365. Find them.
My biggest saving, switched all loads off when everyone sleeps.

 

How does the above sound to you?

100% agree. I must say that I would prefer a monitoring tool of some sorts that I can play around with to try and find the culprits. A friend makes use of the sunny portal and spent one weekend sorting out the leaches.

I must say thank you very much. You have really helped a lot and I'm getting somewhere now.

I think that the idea that I have now (unless you can help with the UPS & solar issue I mentioned at the beginning):

1. Start with UPS & Batteries to keep home office up
2. Add Inverter, MPPT & Panels to start running partially off grid
3. Add additional panels if needed

So now the next question would be what should I look into getting? I'm talking from UPS & Batteries through to Inverter, MPPT & Panels!

UPS:

As I mentioned above the Mecer inverter that I am looking at only supports lead acid by the looks of it. Is that OK or is there something else to look at?

Batteries:

I have no idea here. All I know is that it needs to run the home office and hopefully fridge as well when connected to a proper inverter & MPPT. (We have a Samsung fridge with a digital inverter and A+ energy rating if that helps)

Inverter:

I think 3kVA should do the trick. Now the question is what? Do I get one with a built in MPPT or a seperate MPPT? This is where I really need help!
I see City of Tshwane allows grid feedback, so that would be nice, but from what I read it's quite expensive to do, so not a necessity at all

I've looked at (In no particular order):
SMA Sunny Boy 3.0 Inverter - ~R21000
Victron Phoenix 12V/24V/48V 3kVA-2.4kW Inverter - ~R27000
Axpert MKS Plus 3kVA 2400W 24V Hybrid Inverter - ~R9100 (Why so cheap? Will this do what I require which includes pulling additional from the grid if there's not enough PV?)
MLT Inverters Oasis 324 3kW - 24V Pure Sine Wave Inverter/Charger - ~R24000 (Built in charger)

MPPT:

Again, no idea or preference. This will have to match the batteries & inverter from what I understand

Panels:

Same as above from what I understand. As mentioned the idea would be to run at least the home office & fridge which should in any case be everything there is during the day

Thanks again!
Fred

[___]

Confession, I didn't read the long posts up to here. But I did want to weigh in: My situation in 2013 was similar. I could not afford the financial loss that went with the power failures. I had less than 30k to work with at the time. And back then none of the Taiwanese inverters were available anyway, pretty much the only inverter that ticked all the boxes (allow some self-consumption) was the Victron Multiplus. So I bought the best one my money could stretch to, a 1600VA 24V model (they were a cool 12k back then), added two pretty crappy batteries to it and 300W worth of PV. Then I bought some steel, got out the old welding machine and welded up some frames, and did the install myself. And that was version 1.

The funny thing: I still have that 1600VA inverter. It handles all the stuff you listed (top-loader washing machine, fridge, freezer, televisions, computers, lights), but none of the high-end users (hair dryers, geyser, stove, etc). It turns out that the inverter I bought is a hybrid though (can run grid-interactive, ie mix solar, pv and grid power), and this is where I went with it eventually. As TTT suggests, I use it to run everything below 1.2kw during the day. Any load larger than that simply draws from the grid. So I get my savings, up to 10kwh a day, and everything works except the large stuff.

I will however move to a 3kva at some point, and the only reason I want to do that is 1) so you can heat something in the microwave and make some coffee in the morning, and 2) so the wife's hair dryer works. Happy wife, happy life.

So my opinion, when you have the advantage and/or curse of having to start small: You might be better off with a small Multiplus Compact than a large 5kva Axpert. Yes, they cost more.

[Guest]

We don't buy from Sustainable. :-) No, we don't. 

Look at Current Automation prices. Attached a pricelist for you.

There are two camps here. Axpert or Voltronic and copies of Axperts (everyone bar 2) and Victron (the 2) Plonkster and I. There are more Blue supporters, but they are very quiet or have left, as their systems work. :-) 

Both Plonk and I use 1.2kw inverters, mine a Phoenix, just inverter, as when I started, things where even more expensive than when he started.

Victron's MPPT's and later inverter, are good. Pricey (depends how you see it), but very good. You don't have to sukkel ever, firmware is updated automatically, lots of options to adjust to fit any battery bank, backed by good support etc. vs Axpert, blerrie good price, but no support bar here, and from Australia, clever guys there, to upgrade the firmware.

You want to tinker, tamper, do-your-own-thing, cheap, then go Axpert.
You want to "plug and forget", more options later, the go Victron, and worth the spend if you don't like to tinker.

 

2 hours ago, fredhen said:

Back to the batteries question. I have NO idea what to do battery wise.

Batteries, either Trojan T105RE's or the new Lithium banks / PolyonTech. Both are used by lots of people here on the site.

PolyonTech you can add more batteries later on as you need. UPS charging may be an issue. They are expensive. Use them a lot!
Trojan's needs TLC ito adding water, cannot add more batteries later. Less expensive. UPS can charge them. 4000 cycle on 20%, 1600 on 50% use. Use them a bit.
Or 200ah Truck batteries. Cheapest option, for learning and not draining them below 10% on average, or 50% on very rare occasions. Like a real UPS application. Light use.

Axpert and Victron MPPT's work on all the above, Trojan's are better than truck batteries and PolyonTech is the best, and the most pricey.

Plug and Forget, go PolyonTech. Just need to ensure the UPS can handle the charging.

Or go cheaper, seeing as batteries are going to be replaced in the future, and start with 200ah truck batteries. UPS'es are mostly modified sine wave, if you want the fridge now on UPS, you have to go sine wave, then UPS is not worth it, spend the money rather on a solar inverter. Keep the fridge for later? Focus on stuff that brings money in now.

Inverter with MPPT built in, like Axperts, you decide day 1, 24 or 48v. And best you go 48v.
Victron separate MPPT's are 24/48v auto adjustable, so you can later change over to 48 with 3kva inverter, or stay 24v.

Me, I see no need to go 48v unless you want a big battery bank. I'm 24v. Have Victron MPPT's (2) and can go 48v if I want, if I replace the inverter ... No.
But if inverter ever breaks, maybe then I'l go 48v. 6 years in no sign of issues at all.

 

2 hours ago, fredhen said:

I am assuming you mean disconnecting it from the wall

YES!. All inverters I have sold during the Eskom fiasco, I made sure they can run unplugged, stupid if they cannot. Just earth them.

 

2 hours ago, fredhen said:

gas for your stove

Gas can be more expensive then Eskom. :-) But I hear you. It is good for power issues! And better for ANY inverter not to power a stove.

 

2 hours ago, fredhen said:

The wife added the save the planet part, ...

Good luck on that one. Eskom still has to run, or the country goes up in smoke. To make it all green, she has to start letting go of the hairdryer. Luxury see. :-)
Then she must switch off everything that is not used, lifestyle change, as so many of use here had to "teach" the wifes and kids. Some of use did not make it. Rest their souls .. only joking. Some did end up in hospital, SWAMBO got upset. :-)

 

So, to sum up:
1) Batteries, you have ideas above and a PM. Once you have given us the load, we can help you spec the bank size.
2) The final load, one day, dictates the inverter size.
3) And the above would all be catered for because you will by a MPPT (if you go separate) that can handle any future changes.
4) Panels can be added as needed.

Plonksters suggestion on a small Multiplus is very good idea, with a bigger MPPT for more option later. Start with one, then if you need more power later, get a 2nd one. Maybe you stick with one, like we both have been doing for many years.
AND ... Plonksters system is grid tied, if you want to go that far later. But lets not confuss the matter now. One issue at a time.

 

Last though for now: I have separate circuits for all stuff that is solar.
Fridge / Freezers are on / off solar, based on the season.
Lights are on changeover switch between Eskom (cheaper) and solar (power failures)
All computers TV's, DSTV are on separate circuit. For daytime solar, evenings Eskom, with option to go over to solar with power failures.

This way I control the battery SOC and what is on and what is off, by hand. For summer and winter here is a huge difference, seeing as we have rain in winter.

Geyser is on EV tubes, works best in cloudy weather. PV panels are pretty weak, compared to EV tubes, on a Cpt winter cloudy dayS.
Geyser on solar draws 2000w, so on a small inverter, little else can be on, so you have to spend more for bigger inverter and panels ... 
EV tubes is best for water heating, I have been shown. And you can make it so, with training everyone, that they shower right, and seldom use Eskom, and save the planet, sorry water. 

Once you got solar sorted, read on the forum about saving water, for THAT is saving the planet, like Cpt did collectively, this last few months. 
If I could redo the house, I would have 2 pipe systems. One for toilets / bath / showers for pure rainwater feed, drinking water for municipal water.

Why? Potable water is expensive to do oneself. You don't need potable water for showers / toilets.

VICTRON-2018.pdf

[___]

Time to read the other post and reply a bit more sensibly.

13 hours ago, fredhen said:

Batteries: 

I have no idea here. All I know is that it needs to run the home office and hopefully fridge as well when connected to a proper inverter & MPPT. (We have a Samsung fridge with a digital inverter and A+ energy rating if that helps) 

A decent lead acid bank now costs about the same as a pylontech rack, or only very slightly more. For example, let's say you buy something like Trojan's 85Ah deep cycle 12V batteries, at around 2k each (I expect them to be a little more than that), then a 48V bank sets you back around 8k-10k, and at 50% depth of discharge stores around 2kwh. A single pylontech stores the same, last three times longer, costs 15k, and allows you to extend the bank later. Something to keep in mind though, wish small banks, is they usually allow limited continuous power. For example, that Pylontech rack will want a limit of 35A, which limits you to about 1.6kva in any case. The lead acid bank will want C/5 at most, or 85/5 = 17A, and with lower voltage efficiency you'd be limited to maybe 800W.

13 hours ago, fredhen said:

I think 3kVA should do the trick. Now the question is what? Do I get one with a built in MPPT or a seperate MPPT? This is where I really need help!

I have a direct interest in you buying that blue box, so you are welcome to ignore me if you want :-) I don't think it goes for 27k. My pricelist says 1200 euro, which is less than 20k ex vat. In my experience (they are built in India, the price in Europe is usually more than here), it should go for less than that. The truth is that all the other makes are around that price, if you look at Goodwe for example, or even the infinisolar which though slightly cheaper is at least of the same order. Those are also hybrids and closer to being natural competitors.

13 hours ago, fredhen said:

Axpert MKS Plus 3kVA 2400W 24V Hybrid Inverter - ~R9100 (Why so cheap? Will this do what I require which includes pulling additional from the grid if there's not enough PV?)

The reason for it being so cheap has been debated ad nauseam. My theory is that they make up in bulk for what they lose out in profit, and that their large footprint in the UPS market means that the tiny solar market they sell to is money for mahala. The other makers are dedicated solar manufacturers and usually expect to make profit on each unit.

The axpert switches back to grid if the load is too high or the battery too low. It is hard-on/hard-off. Either the whole load is from the grid, or the whole load is from the battery. If it's in inverter mode and a large load starts, it moves to the grid entirely. The hybrid inverters only takes the DIFFERENCE from the grid, so if a 2kw load starts it would take 1kw from the batteries and 1kw from the grid for example (depending on how you set it up).

Edited to add: Just for the sake of full disclosure, remember that you need extra equipment to use the nice features of the Multiplus. You usually need to invest in the communications dongle (The mk3-usb, about another 1k extra), possibly one of the control computers (Venus-GX, CCGX, or make your own with a Raspberry Pi), and then all the other cool stuff becomes available. You don't have to buy all of that stuff on day one, and even just the mk3-usb and the assistant stack (which is like small apps that runs on the inverter and gives you extra features) already makes it worth it. The point is: You get the  best of both worlds, as TTT said, it's install and forget BUT it is also very tinker friendly.

Edited July 15, 2018 by plonkster

[fredhen]

 

 

10 hours ago, The Terrible Triplett said:

We don't buy from Sustainable. :-) No, we don't. 

Look at Current Automation prices. Attached a pricelist for you.

Good to know, thanks

10 hours ago, The Terrible Triplett said:

There are two camps here. Axpert or Voltronic and copies of Axperts (everyone bar 2) and Victron (the 2) Plonkster and I. There are more Blue supporters, but they are very quiet or have left, as their systems work. :-) 

Both Plonk and I use 1.2kw inverters, mine a Phoenix, just inverter, as when I started, things where even more expensive than when he started.

Victron's MPPT's and later inverter, are good. Pricey (depends how you see it), but very good. You don't have to sukkel ever, firmware is updated automatically, lots of options to adjust to fit any battery bank, backed by good support etc. vs Axpert, blerrie good price, but no support bar here, and from Australia, clever guys there, to upgrade the firmware.

You want to tinker, tamper, do-your-own-thing, cheap, then go Axpert.
You want to "plug and forget", more options later, the go Victron, and worth the spend if you don't like to tinker.

I must be honest and say that I would prefer a set and forget setup. I've had a chat with my dad who has a battery backup at home and found out that he's using a Multiplus and also didn't tinker with it once in the last 3 or so years. That along with what you've said pretty much sold me. on Victron (congrats)

10 hours ago, The Terrible Triplett said:

Batteries, either Trojan T105RE's or the new Lithium banks / PolyonTech. Both are used by lots of people here on the site.

PolyonTech you can add more batteries later on as you need. UPS charging may be an issue. They are expensive. Use them a lot!
Trojan's needs TLC ito adding water, cannot add more batteries later. Less expensive. UPS can charge them. 4000 cycle on 20%, 1600 on 50% use. Use them a bit.
Or 200ah Truck batteries. Cheapest option, for learning and not draining them below 10% on average, or 50% on very rare occasions. Like a real UPS application. Light use.

Axpert and Victron MPPT's work on all the above, Trojan's are better than truck batteries and PolyonTech is the best, and the most pricey.

Plug and Forget, go PolyonTech. Just need to ensure the UPS can handle the charging.

Or go cheaper, seeing as batteries are going to be replaced in the future, and start with 200ah truck batteries. UPS'es are mostly modified sine wave, if you want the fridge now on UPS, you have to go sine wave, then UPS is not worth it, spend the money rather on a solar inverter. Keep the fridge for later? Focus on stuff that brings money in now.

The UPS will be short term. I will just need something when I get back and start from home that will keep me going if there are any issues. That will only be the PC's, monitors and a desk lamp. No fridge then. But I would like to get on a proper Inverter, Solar & Battery setup as soon as possible, so I'll most likely only end up using the UPS for a month or two.

In that case I guess the Trojans will be the best bet. Why specifically the T105RE's and not their solar batteries? (Out of interest)

 

10 hours ago, The Terrible Triplett said:

Inverter with MPPT built in, like Axperts, you decide day 1, 24 or 48v. And best you go 48v.
Victron separate MPPT's are 24/48v auto adjustable, so you can later change over to 48 with 3kva inverter, or stay 24v.

Me, I see no need to go 48v unless you want a big battery bank. I'm 24v. Have Victron MPPT's (2) and can go 48v if I want, if I replace the inverter ... No.
But if inverter ever breaks, maybe then I'l go 48v. 6 years in no sign of issues at all.

As I mentioned I do want to 'future proof' and be able to go with more panels and/or a bigger battery bank, so I would obviously then go 48V, but that will obviously add to the initial cost especially considering adding twice as many batteries to get to 48V.

I am guessing that it might not benefit me now, but later down the line? (I'm OK with that, but just keeping the budget in mind)

10 hours ago, The Terrible Triplett said:

Good luck on that one. Eskom still has to run, or the country goes up in smoke. To make it all green, she has to start letting go of the hairdryer. Luxury see. :-)
Then she must switch off everything that is not used, lifestyle change, as so many of use here had to "teach" the wifes and kids. Some of use did not make it. Rest their souls .. only joking. Some did end up in hospital, SWAMBO got upset. :-)

I guess it's the every bit helps kind of mindset. If I can run the home office and fridge off solar during the day and get 1 hour of lights and TV on a small DOD from the batteries at night it's a start.
Trust me when I say that I won't get involved in the hairdryer conversation. As @plonkster said, Happy wife, Happy life.
I definitely agree about the lifestyle changes. And we're both up for it at least. If we can run off solar during the day and use less at night everyone feels better. Although I guess this means that I'll have to now do the laundry during the day?

 

10 hours ago, The Terrible Triplett said:

So, to sum up:
1) Batteries, you have ideas above and a PM. Once you have given us the load, we can help you spec the bank size.
2) The final load, one day, dictates the inverter size.
3) And the above would all be catered for because you will by a MPPT (if you go separate) that can handle any future changes.
4) Panels can be added as needed.

Plonksters suggestion on a small Multiplus is very good idea, with a bigger MPPT for more option later. Start with one, then if you need more power later, get a 2nd one. Maybe you stick with one, like we both have been doing for many years.
AND ... Plonksters system is grid tied, if you want to go that far later. But lets not confuss the matter now. One issue at a time.

Load wise I can't say for sure. But as I mentioned I would want to run as much as possible off-grid during the day, but the main requirement is a backup in case of power failure which can last me from 8 to 5 on a rainy day. But for that I will manually switch everything off except for the router, pc, monitor and desk lamp. So I believe a smallish bank will do? Or am I looking at it wrong?

Based on the above and what both of you mentioned I believe a 3kVA will be OK. Yes, a smaller 1.8kVA setup will easily run the office, but I'd prefer to have the extra headroom. And as I'm in budgeting phase now, I'd prefer to budget for that and decide finally when I get there.

I am then guessing that i will have to go with a 48V inverter as part of the future proofing?

• 48/3000 Victron Phoenix and seperate MPPT?
• 48/3000 Victron Multiplus with built in charger?
• 48/3000 Victron Multiplus II with built in charger?
• 48/3000 Victron EasySolar with built in charger?

Otherwise the same as above in 24V?

 

10 hours ago, The Terrible Triplett said:

Last though for now: I have separate circuits for all stuff that is solar.
Fridge / Freezers are on / off solar, based on the season.
Lights are on changeover switch between Eskom (cheaper) and solar (power failures)
All computers TV's, DSTV are on separate circuit. For daytime solar, evenings Eskom, with option to go over to solar with power failures.

This way I control the battery SOC and what is on and what is off, by hand. For summer and winter here is a huge difference, seeing as we have rain in winter.

Is that easy enough to configure to be able to change between Eskom and solar? I will most likely get someone to install for me, so I'd just like to know if it's something easy to do?

To be honest your setup seems to be similar to what I am looking for with battery mainly for power failures, although I guess using them on a ~10% DOD gets some use out of the spend.

10 hours ago, The Terrible Triplett said:

Geyser is on EV tubes, works best in cloudy weather. PV panels are pretty weak, compared to EV tubes, on a Cpt winter cloudy dayS.
Geyser on solar draws 2000w, so on a small inverter, little else can be on, so you have to spend more for bigger inverter and panels ... 
EV tubes is best for water heating, I have been shown. And you can make it so, with training everyone, that they shower right, and seldom use Eskom, and save the planet, sorry water. 

Once you got solar sorted, read on the forum about saving water, for THAT is saving the planet, like Cpt did collectively, this last few months. 
If I could redo the house, I would have 2 pipe systems. One for toilets / bath / showers for pure rainwater feed, drinking water for municipal water.

Why? Potable water is expensive to do oneself. You don't need potable water for showers / toilets.

As soon as everything is up and running the geyser will be the next project. I will most likely not have the geyser on solar for the start, but I'll discuss that closer to the time. But getting a geyser solution is a must.

Saving water is a must and is something we are already trying as well. I was actually looking into a 2 pipe system a while back. If only we could build houses from scratch.

Thanks again for the help!

[fredhen]

 

24 minutes ago, plonkster said:

Time to read the other post and reply a bit more sensibly.

I really need to start typing less. As I saw this sentence I cringed thinking I have to read a long reply to my long replies 

25 minutes ago, plonkster said:

A decent lead acid bank now costs about the same as a pylontech rack, or only very slightly more. For example, let's say you buy something like Trojan's 85Ah deep cycle 12V batteries, at around 2k each (I expect them to be a little more than that), then a 48V bank sets you back around 8k-10k, and at 50% depth of discharge stores around 2kwh. A single pylontech stores the same, last three times longer, costs 15k, and allows you to extend the bank later. Something to keep in mind though, wish small banks, is they usually allow limited continuous power.

Good to know, thanks. Perhaps I should skip the UPS and just go for it once I'm back as the batteries seems to be the problem. Especially if I'm only planning on using the UPS for a month or two during which there will most likely not be an outage.
I'm not really looking for lots of power for everything. The main thing is to have the home office up during an outage and maybe the fridge. Will a small bank still work?

25 minutes ago, plonkster said:

I have a direct interest in you buying that blue box, so you are welcome to ignore me if you want :-) I don't think it goes for 27k. My pricelist says 1200 euro, which is less than 20k ex vat. In my experience (they are built in India, the price in Europe is usually more than here), it should go for less than that. The truth is that all the other makes are around that price, if you look at Goodwe for example, or even the infinisolar which though slightly cheaper is at least of the same order. Those are also hybrids and closer to being natural competitors.

The 48/3000 Phoenix I'm looking at now is about 14k - 16k.

Any reason not to go for something with a built in charger?

25 minutes ago, plonkster said:

...Either the whole load is from the grid, or the whole load is from the battery...

That settles it then.

 

25 minutes ago, plonkster said:

Edited to add: Just for the sake of full disclosure, remember that you need extra equipment to use the nice features of the Multiplus. You usually need to invest in the communications dongle (The mk3-usb, about another 1k extra), possibly one of the control computers (Venus-GX, CCGX, or make your own with a Raspberry Pi), and then all the other cool stuff becomes available. You don't have to buy all of that stuff on day one, and even just the mk3-usb and the assistant stack (which is like small apps that runs on the inverter and gives you extra features) already makes it worth it. The point is: You get the  best of both worlds, as TTT said, it's install and forget BUT it is also very tinker friendly.

Main thing for me would be to get an idea how much is being generated, used and charged similar to this and then anything that is an absolute must. The rest I can add later if it's only nice to haves.

[___]

37 minutes ago, fredhen said:

I am then guessing that i will have to go with a 48V inverter as part of the future proofing?

Price difference between the 24V and 48V models are negligible. If you search this forum some years back you may find some musings and reasons: Back then 24V meant less batteries, ie you could start even smaller. Now that many LFP batteries come only in 48V configurations, future proofing requires that you go with 48V.

18 minutes ago, fredhen said:

Any reason not to go for something with a built in charger? 

Get the  Multi! The phoenix is just an inverter, it's not even hybrid, it can't run ESS (the hybrid storage system) later. In addition, the 48V 3KVA Multiplus is by far the most popular unit and because of that it benefits from volume, ie it is well priced.

18 minutes ago, fredhen said:

Main thing for me would be to get an idea how much is being generated, used and charged similar to this and then anything that is an absolute must. The rest I can add later if it's only nice to haves.

VRM is free. The official control units are pricey (over 4k for a Venus-GX, around 8k for a CCGX), but they are fully loaded with all sorts of connections, they are absolutely worth it for someone who uses all those connections (especially the venus-GX, a USB canbus interface is not cheap and you'd be hard-pressed to roll your own, even half as neat, at the same price, also compare competition eg solarlog to get an idea). But you can do it with a raspberry pi and various cables. I've previously estimated the cost of doing it this way (doing it properly with a din enclosure) around 2.5k. Just one note: Pi 3B support is lagging a bit behind, it's on my todo list :-)

Edited July 15, 2018 by plonkster

[___]

Missed this one.

26 minutes ago, fredhen said:

The main thing is to have the home office up during an outage and maybe the fridge. Will a small bank still work?

Absolutely. I used to run my fridge and freezer from a 200Ah 24V bank, did so for more than two years. A+ fridges should have a start peak of no more than maybe 800W (my A++ Bosch does around 450W), and they rarely require much more than about 1kwh or so to remain cold. My 200Ah bank was sufficient to ride through 4 hour outages easily.

About the UPS: How about spending that money on a small generator instead, if you want to buy a bit more time? People sell those things cheaply in the second hand market, just make sure it works before you hand over any cash :-) If you end up with a three-day outage (as some of our friends in Pretoria East right now, apparently a substation was damaged during "protests"), that's then also your future insurance counter-weighed against the small bank. Second-hand generators also have good resale value (eg, they sell for close to what you paid... second hand ;-) ).

[fredhen]

 

1 hour ago, plonkster said:

Price difference between the 24V and 48V models are negligible. If you search this forum some years back you may find some musings and reasons: Back then 24V meant less batteries, ie you could start even smaller. Now that many LFP batteries come only in 48V configurations, future proofing requires that you go with 48V.

That was my thinking. Less batteries. But at the end of the day I also don't want to rush into something and then regret it. Hopefully in ~6 months when I'm back LFP prices came down even more.

1 hour ago, plonkster said:

Get the  Multi! The phoenix is just an inverter, it's not even hybrid, it can't run ESS (the hybrid storage system) later. In addition, the 48V 3KVA Multiplus is by far the most popular unit and because of that it benefits from volume, ie it is well priced.

Thank you! Now I'm getting somewhere and getting excited!

Between these?

• MultiPlus 48/3000/35-50
• MultiPlus-II 48/3000/35-32
• EasySolar 24/3000/70-50 MPPT150/70 (Built in Colour Control)

Looks like a if you want everything get the EasySolar otherwise a Multi and build up from there. Is there a big difference between the MultiPlus and MultiPlus II or not for my use?

1 hour ago, plonkster said:

VRM is free. The official control units are pricey (over 4k for a Venus-GX, around 8k for a CCGX), but they are fully loaded with all sorts of connections, they are absolutely worth it for someone who uses all those connections (especially the venus-GX, a USB canbus interface is not cheap and you'd be hard-pressed to roll your own, even half as neat, at the same price, also compare competition eg solarlog to get an idea). But you can do it with a raspberry pi and various cables. I've previously estimated the cost of doing it this way (doing it properly with a din enclosure) around 2.5k. Just one note: Pi 3B support is lagging a bit behind, it's on my todo list :-)

To be honest though that's a bit over my head at this stage, so I'll study up on what exactly it does or can do. I guess even more reason to upgrade my secondary Pi 2B to a 3B and move the 3 to secondary  but I also want it done properly, so rather not..

1 hour ago, plonkster said:

About the UPS: How about spending that money on a small generator instead, if you want to buy a bit more time? People sell those things cheaply in the second hand market, just make sure it works before you hand over any cash :-) If you end up with a three-day outage (as some of our friends in Pretoria East right now, apparently a substation was damaged during "protests"), that's then also your future insurance counter-weighed against the small bank.

I am one of the friends in Pretoria East... But we actually spoke about going solar last weekend, so we both had a good laugh on Tuesday when we found out we will be without power for about a week. (Day 6 today and ETR is only tonight) Thank goodness for family on the other side of the power line.

UPS wise, yep. I think I'm just jumping the gun a bit. A small generator should be more than enough for the odd power outage.

Thanks a lot!

[Guest]

2 hours ago, fredhen said:

That along with what you've said pretty much sold me. on Victron (congrats)

It was not the intention, I just wanted to share the Blue teams passion for the expensive equipment we have. No, we are not justifying the expense, it really works out the box. I mean, who in this world gives a 5 year warranty, free software and support?

 

2 hours ago, fredhen said:

Why specifically the T105RE's

T105RE's are 6v batteries and they have 4000 cycles (8 years) at 20% DOD. So you can use them to 20% each and every day.

If you push them to 50%, you have 1600 cycles.

They are tried and tested solar batteries. No surprises with them if you follow the rules and keep them filled.

On T105RE's you aim for 20% DOD on average. 10% is not enough to use them over their lifetime. 10% is good on UPS batteries.

 

2 hours ago, fredhen said:

I would obviously then go 48V,

That decision is made when you buy the solar inverter. Till that point, you can be 12/24/48v, as UPS inverters are cheap.

 

2 hours ago, fredhen said:

If I can run the home office and fridge off solar during the day and get 1 hour of lights and TV on a small DOD from the batteries at night it's a start.

You will tweak the system part by part till you find the perfect medium, that is where Wife does not give you a lot of words and ultimatums about why the power is off when you are far far away. It is a journey, if she buys in, it is really cool. From what I gather, wife is in, so you are good to go. :-)

 

2 hours ago, fredhen said:

... router, pc, monitor and desk lamp. So I believe a smallish bank will do? Or am I looking at it wrong?

I used to run a Intel server, 27" screen and router for up to 8 hours off 2 x 105ah batteries, repeatedly. That was pushing them yes, as they did get close to 50% DOD and are NOT designed for that, not like solar batteries are.

A+ fridges and freezers are supposed to be good for 12-48 hours, T&C's apply. Then there is also a case to be made for what is in them. we buy very expensive fridges to keep a few rands worth of goods cool. If you fridge/freezer is full, that is another case.

Therefor today I have 4 x T105RE's. They can take it with ease.

 

2 hours ago, fredhen said:

Otherwise the same as above in 24V?

My thinking is, and some on the forum disagrees, is that 12/24v has a benefit in that when, not if, when a battery goes, you have less of an expenses than when one battery goes on a 48v bank. That one problem battery drags the rest down, so you have a choice, buy 1 new one and drag it down, or replace all.

Now a 48v bank has more storage yes, but you can have same storage on a 24v bank, if you need that.

It all comes down what you want powered for how long and what max amps come out of the batteries.

Computers, routers, lights A+ fridge and that, long backup times, 12/24v is fine. A house, 48v.

Cheapest bank is a 12v system BUT you are limited in the max system size. My rule of thumb, as in continuous, not peaks:
12v - ideal 250w pushing at 1000w (Victron has 12v 5000va inverters - good for peaks, never continuous on 12v)
24v - ideal 800w pushing at 2000w
48v - above 3000w, you can go big.

So it is knowing your continues load, making sure the bank is not stressed, that is it.

O, 12v has more amps in the cables than say 48v. Bleh say I, go 35mm cables (if you want go 50mm) on the batts and to inverter and be done with it.
For if a 48v system pulls 5000w or a 12v system pulls 1000w, if the connections or fuses are not correctly done, both systems will have an issue. :-) 

12v just sparks better see, bigger bang for your buck ... literally. :-)

Any case, the inverter is the key deciding factor, 12/24/48, as the MPPT, batteries and panels, can do all three voltages. 

So call is yours, 48v or not, keeping in mind the new batt tech in Pylontechm being 48v.

 

2 hours ago, fredhen said:

Is that easy enough to configure to be able to change between Eskom and solar? I

Plonskter can guide you. I would budget for a VenusGX, cable per deivce, for the magic happens in there.

And do not forget the BMV battery monitor. It is the key in switching the system.

Happy batteries = happy wife. (... if you have to spend thousands on a new bank due to overuse)

 

2 hours ago, fredhen said:

Perhaps I should skip the UPS ...

I am starting to think yes, skip the UPS, go Multiplus direct.

Would keep controller apart, you have more room to maneuver ito the future or if something has to break.

I view it as so:
Panels + MPPT + batteries the entire fuel system. 
BMV the gauge of the "tank"
Inverter the engine engine.

But, if you want it all as one, nothing wrong with that at all. It has more of a Plug and forget, with slightly less room to move.

43 minutes ago, fredhen said:

A small generator should be more than enough for the odd power outage.

Multiplus and VenusGX and BMV combination can auto-start a generator, if the gennie has the capability.

Or BMV alarm goes off, DOD is say 30%, you can manually switch on the gennie. 

[Guest]

11 minutes ago, The Terrible Triplett said:

Or BMV alarm goes off, DOD is say 30%, you can manually switch on the gennie. 

A thought on that. gennies are cheaper than a huge bank you seldom use. Like with ad hoc extended power failures.

And, because the gennie is used to power stuff AND charge the batts, every ounce of fuel is optimally used.

Edited July 15, 2018 by Guest

[Guest]

3 hours ago, fredhen said:

I really need to start typing less. As I saw this sentence I cringed thinking I have to read a long reply to my long replies

Don't. You are new, lots of thoughts and questions. Lots of answers and explanations.

While from now, someone reads it all, identifies with what you asked, and learns from it. Time is then well spent.

This is a information site, not a Google quick short answer site. :-) 

[___]

2 hours ago, fredhen said:

Between these?

• MultiPlus 48/3000/35-50 
• MultiPlus-II 48/3000/35-32
• EasySolar 24/3000/70-50 MPPT150/70 (Built in Colour Control) 

The Multiplus-II has a steel case, where the others have aluminium cases. The Multiplus-II is also not significantly cheaper (in fact it is bout 20 Euros more expensive), but it does pack a bit more features. It has slightly lower no-load consumption and it has the anti-islanding features of the Multigrid. But it also costs the same as the Multigrid. The only other feature it has is a detachable current sensor, so in an ESS setup it saves you some money on adding a separate energy meter. The Multiplus has a higher-rated transfer switch though (be sure to get the 35-50). Also see here.

Personally I'd get the Multiplus, or possibly the Multigrid if it is not too much more expensive. Difference? The Multigrid is certified for NRS097-2-1, in other words, it can be tied to the grid in South Africa. The Multiplus only complies with NRS097-2-1 if you add another anti-Islanding switch.

The easysolar is nice and all, but doesn't in my mind represent much of a saving over individual components, and it sort of commits you to an all-at-once decision. I personally prefer multiple smaller MPPTs rather than one large 150/70. Also, if you go 24V (nothing wrong with that), it limits your battery choices later when you want to go LFP. In terms of the best value options available now: You'd be limited to the FreedomWon Lite-mini battery, as that is one of the few 24V batteries made locally.

[___]

2 hours ago, The Terrible Triplett said:

Plonskter can guide you. I would budget for a VenusGX, cable per deivce, for the magic happens in there. 

And do not forget the BMV battery monitor. It is the key in switching the system. 

There is rather a lot to explain and I don't want to overcomplicate things at this point. But let me put it simply.

IF you have a Venus-GX, and all your solar chargers are Victrons, then you don't need the BMV. The Multi already has the ability to track the state of charge, and the Venus-GX tells the Multi about what the solar chargers are doing, so the Multi keeps a good state of charge even without a BMV. This also makes switching to and from the grid easy or even run grid-parallel.

But if you decide not to go with a Venus-GX, then I would suggest getting the BMV instead. There is a way to configure the Multi so it takes a signal from the BMV to switch to and from the grid. This is a hard-on/hard-off configuration, it does not mix power from different sources.

Also, when you later buy your new LFP battery, the BMS of that battery will tell you about the SOC and you won't need the BMV anymore.

If it was me, I'd get the Venus-GX and leave the BMV, unless I had money to burn. It may sound odd... but it isn't, if the chargers are all victron and there are no DC loads, and you have a Venus-GX or CCGX, you don't need the BMV.

 

2 hours ago, The Terrible Triplett said:

From what I gather, wife is in, so you are good to go. :-)

The day my wife bragged to her colleagues in the office was the day I knew she bought in. The power went out, and she announced that she's going home because there's power there...

Something else to be said about this: It's not going to help that you have power, but your internet connection goes down because some part of it runs from the grid or has only limited backup. Make sure you have more than one internet connection if it is really important to you.

[Guest]

1 hour ago, plonkster said:

I'd get the Venus-GX and leave the BMV,

And there I learn something!

My upgrade path after my Phoenix (if it ever goes) is then all set for a Multigrid, have all the parts.

Sell the BMV and to offset some of the new inverters cost. :-) 

[___]

1 hour ago, The Terrible Triplett said:

And there I learn something!

Let me get technical (because I love it), and bolster my story with some math!

If you draw a chart with time on the horizontal axis (let's say in hours) and current on the vertical axis (in ampere), then if you consider the area UNDER the line, it would be current multiplied by time, or amp-hours. If you've had calculus training at some point in your career, then you know the procedure for calculating the area under the line is known as integration, and if you've done any applied mathematics and/or numerical analysis type courses, then you know there are ways to approach the area using various techniques, the simplest which is newtonian integration.

Newtonian integration essentially draws little narrow trapeziums below the curvy line and work out the area of each trapezium, and add them all. There are even simpler methods where you draw a narrow little rectangle so that the middle of the rectangle is on the top line (or consider converting a line chart to a bar chart so that there are millions of little rectangular bars for each data point). Again, the area of a rectangle is simply width times height, or in this case, current multiplied by delta-T.

This is basically exactly what the BMV and the Multi does. The reason the Multi could not do it when you had DC chargers, was that it didn't know about "external" current. So the obvious answer is to make it aware of it. And it really is that simple. Every couple of seconds, you take the combined current from all the MPPTs and tell the Multi that "by the way, there's also this 52.3A coming from somewhere else", and then the Multi adds it in when doing its little integration dance.

The result is an SoC determination that isn't 100% accurate... but guess what, lead acids aren't that consistent anyway, lithiums don't really get hurt if you're off by a bit, and it's a thousand times better than using the voltage to estimate it (at least for lead acid).

[fredhen]

Thanks for all the help and replies. I really appreciate it! I'll go through it properly tomorrow when I have electricity again 

Quick question:
Will the MultiGrid be able to work with PV without having batteries or an MPPT or will I need an MPPT or both in order to power from PV? (From what I've read it seems that I need a seperate solar inverter without batteries & MPPT, but I'd just like to confirm)

The idea I have now (if the above is possible) is:

• Get a small generator once I start to keep the home office running in the unlikely event of an outage.
• Get the MultiGrid and PV to start making use of some PV
• Get an MPPT and battery/s (Or just battery/s if MPPT is required to start generating with PV

Obviously the battery/s will be a big expense, so if it can be delayed due to me having the generator that'll be great as I'm hoping the LFP prices will keep going down.

[___]

2 hours ago, fredhen said:

seperate solar inverter without batteries & MPPT

There is some confusion here...

2 hours ago, fredhen said:

• Get the MultiGrid and PV to start making use of some PV 
• Get an MPPT and battery/s (Or just battery/s if MPPT is required to start generating with PV 

The Multiplus/Multigrid can't work without batteries. And you need a separate MPPT, it is not bundled with the inverter. But you can also use a PV-inverter instead of an MPPT (something like Fronius or SMA), this is essentially an inverter that turns PV directly into AC power and feeds it into the grid, no batteries. The Multi can work with such an inverter and charge the batteries from the AC side. But this is really not advisable for your situation, because the PV-inverter goes down when the grid goes down, and it costs much more than an MPPT.

Watch the ESS webinar here for an overview (that's Matthijs Vader btw, the MD). Around 4:45 is the system you want, PV coupled to the DC bus. At 6:50 he explains how to run without the energy meter, you will likely do that as well, at least in the beginning. At 24:00 he explains why you want an MPPT over a PV inverter.

The "color control" is the older control computer with an LCD screen, called the CCGX for short. The Venus-GX is a newer and cheaper option without the LCD (just so you know). The software also runs on the Raspberry Pi.

You will likely not start with an ESS system, but I still think it is best to have an idea of the possibilities.

[Guest]

13 hours ago, plonkster said:

At 24:00 he explains why you want an MPPT over a PV inverter.

That made a lot of sense. And when he said, if you don't get paid, still feed back, it is easier and simpler. I like that logic. Why waste money and complicate your system design.

Let me guess, the pic below is not allowed in SA, as it will feed back?
ESS without meter:

Edited July 16, 2018 by Guest

[fredhen]

3 hours ago, The Terrible Triplett said:

Let me guess, the pic below is not allowed in SA, as it will feed back?

The way I understood that bit was that it is almost the recommended configuration for SA and you can set it to not feed back which should then make it OK?

Edit: I missed your first sentence. It'll actually be good to know although I suppose we will have to set it not to feed back from what I understand even though we don't get paid.

Edited July 16, 2018 by fredhen

[fredhen]

Back to the rest of all the answers:

23 hours ago, The Terrible Triplett said:

Computers, routers, lights A+ fridge and that, long backup times, 12/24v is fine. A house, 48v.
..
keeping in mind the new batt tech in Pylontechm being 48v.

I think based on the idea of wanting to be able to expand the best would be to go 48V although that means having to get a 48V battery which may delay getting it all, but that'll be the better option I suppose.

 

23 hours ago, The Terrible Triplett said:

skip the UPS, go Multiplus direct.

Would keep controller apart, you have more room to maneuver ito the future or if something has to break.
..
A thought on that. gennies are cheaper than a huge bank you seldom use. Like with ad hoc extended power failures.

For what I'm looking at I agree. Just a small generator for starters until I can afford the rest.

 

On 2018/07/15 at 2:58 PM, The Terrible Triplett said:

Don't. You are new, lots of thoughts and questions. Lots of answers and explanations.

While from now, someone reads it all, identifies with what you asked, and learns from it. Time is then well spent.

Thanks! The little that I do know I've learnt reading forums, so that makes sense. Hopefully somewhere down the line someone with the same idea can have a look at this and get answers.

 

 

[fredhen]

22 hours ago, plonkster said:

Personally I'd get the Multiplus, or possibly the Multigrid if it is not too much more expensive. Difference? The Multigrid is certified for NRS097-2-1, in other words, it can be tied to the grid in South Africa.

From what I see there's not that big of a difference and seeing how Tshwane allows it, I suppose it's best to have the option available. So grid it hopefully is.

 

21 hours ago, plonkster said:

if the chargers are all victron and there are no DC loads, and you have a Venus-GX or CCGX, you don't need the BMV.

Makes sense and I must say I like the CCGX especially after watching the webinar, so that's almost a must for me from the start. And as I'll be going 48V I'll most likely wait a couple of months longer and get a LFP in any case.

 

21 hours ago, plonkster said:

The day my wife bragged to her colleagues in the office was the day I knew she bought in. The power went out, and she announced that she's going home because there's power there...

Something else to be said about this: It's not going to help that you have power, but your internet connection goes down because some part of it runs from the grid or has only limited backup. Make sure you have more than one internet connection if it is really important to you.

I found out yesterday that she's been telling everyone already, so I think I'm OK.
Internet wise, yip. Luckily most cell companies also have generators, so should the fibre go down I should be OK with the LTE backup.

 

14 hours ago, plonkster said:

The Multiplus/Multigrid can't work without batteries. And you need a separate MPPT

This was just a long shot in hoping that I can delay the battery purchase and start using PV.
The idea is to have PV -> MPPT -> Inverter knowing that it will go down should the grid go down, but at least using it while saving up for the battery instead of only buying everything at once.
By the looks of it it's not possible, but I just thought about it.

 

14 hours ago, plonkster said:

You will likely not start with an ESS system, but I still think it is best to have an idea of the possibilities.

I actually don't see why not have the ESS system as it's exactly what I want.

[___]

3 hours ago, The Terrible Triplett said:

Let me guess, the pic below is not allowed in SA, as it will feed back?

It is allowed. It uses the current sensor on the input of the Multi instead of an external meter (you just have to configure it to not use the grid meter, under Settings->ESS on the CCGX/Venus-GX).

The upside: No need to buy a energy meter. And the control loop runs inside the Multi instead of the CCGX, so it regulates a bit faster.

The downside: All loads needs to be on (one of) the outputs.

Remember that everything up from 3kva has two outputs. The second output goes down with the grid, only the first output (critical loads) runs from the inverter, but the power of both outputs reflects on the input and hence ESS compensates for loads on both. You just have to be sure your loads are below the maximum limits (50A total usually, which is close to the 60A breakers most single-phase houses have).

So simply put your geyser and the other large loads on the second output.

I think there is still an advantage to using a current meter, because it leaves your house wiring mostly untouched (except for the circuits for the critical loads that you have to split out).