Advice - solar expansion

[mrb13676]

Looking for some advice form the hive mind please…

Current setup - 9x300W panels with a Victron SmartSolar grid tie inverter on one of our three phases. - 8 deep cycle (non Lipo) batteries.
Other two phases have pool and geyser, and some of the stove/oven respectively.

Geyser is a solar geyser with indirect heating (yes, i know…. got some bad advice)

On my HA energy dashboard the big consumers still are the geyser and pool pump (1.1kw but seems to run at 600W once running).
The tribe of the long hair insist on hot water being available in the morning up until 9:00 (and then whenever they feel like showering.…)
It kills me to see solar power not being used during the day - on a good day we can generate 2800W but if it’s not actively being used it goes to waste.
I have tried to connect the pool onto the phase that has the solar but it trips the inverter.

The batteries are a bit meh as the inverter seems to cut off during load shedding when volatage is 48V even though the inverter reports 60-65% charge. Maybe I don’t understand the batteries properly…

I’m really at my wit’s end as we are still using 1500KWh on a summer month and worse in winter.
Batteries and another inverter to run the geyser - i.e to warm the water in the morning before the sun starts its work?
Pool pump onto another inverter or change to a DC solar pool pump - was quoted 35K Ronts for that which seems steep……??

Any thoughts would be much appreciated as I find a lot of the people installing solar stuff don’t actually know how to deal with ‘complicated’ setups and use requirements…

 

[itareanlnotani]

The batteries are a bit meh as the inverter seems to cut off during load shedding when voltage is 48V even though the inverter reports 60-65% charge.

If the batteries are at 48v, they're discharged.
14.4v* is usual fully charged voltage for batteries, so 4 in series should be sitting around 57.6v or so when charged. With 8 batteries you really need a BMS. I suspect they're at end of life, and the inverter settings haven't been set correctly, which is why they're dead.

My suggestion to you will be this - If you haven't already, buy a variable speed pump for the pool. They will sit at lower rpm's and use far less electricity when running.

Next - let me know your current setup - in terms of equipment. Take photos if you don't know.
The probably answer is going to be replace the batteries with Lithium (LFP), but lets see whats up first.


*Value Depends on chemistry - you don't mention what type of Dead Acid - AGM, etc, but on average this value.

Longer answer to your other questions will need more info from you.
My tentative suggestion would likely be add panels, add storage, and reduce usage, but let's see first!

 

[Kawak]

I will breakup your situation and tackle them individually. however, your monthly bill before and after solar install will tell a lot about how efficiently your solar system is.

@itareanlnotani is likely correct, your batteries are gone, if there were standard 100ah lead batteries, they were way to small for your solar array, depending on where you are, your solar system is likely able to produce 16KW per day, you will want a battery bank that is at least able to handle 10KW, on lead, that means about 16 batteries @ 50% discharge. if LFP you will need to size that accordingly @ 20% excess at least, ideally, you want to be able to store an entire days worth of power.

You mentioned smart grid tie, why is this not feeding the grid directly? depending on where you live, there are different rules, you should also be able to do grid tie limiting where the inverter never exports, I'm asking this because you mention the pool pump tripping your inverter which sounds like the inverter is trying to supply power directly and not acting as a grid tie inverter, since your batteries are likely gone, your solar system @ 2.7kw is all that is likely available and therefore it trips as your 1.1kw pool pump likely draws way more on startup.

Solar hot water is a difficult one if people want to shower in the morning, I opted for low pressure, direct vacuum tube solar (cheap and lasts forever) mostly because I can control when cold water is injected into the geyser. I also installed 3 x 200l units for my home, one feeding another, to guarantee hot water all day, system is also able to ride a day of no sunshine. Pressure issue is easily mitigated with a small booster pump. In your case, having more solar geysers hooked up in a chain will ensure more hot water availability. This is however a very costly exercise.

 

[mrb13676]

Next - let me know your current setup - in terms of equipment. Take photos if you don't know.
The probably answer is going to be replace the batteries with Lithium (LFP), but lets see whats up first.


*Value Depends on chemistry - you don't mention what type of Dead Acid - AGM, etc, but on average this value.

Longer answer to your other questions will need more info from you.
My tentative suggestion would likely be add panels, add storage, and reduce usage, but let's see first!

Ta.
The batteries are Mixtech EFB 12V deep cycle - Theyre flooded batteries I guess this means lead acid..
There are 8 - and at the moment the inverter shows them at 50.6V - looking back on the last 14days voltage never went above 58V and 100% charge.... Seems that there may be an issue.
The Victron Smart Solar MPPT 150/100 inverter is set to optimize (with battery life).
It is also set to put DC PV back to grid but not AC PV? - I live in Jhb (city power) - not sure if we can send back to the grid..

It's a bit daunting..

 

[mrb13676]

I will breakup your situation and tackle them individually. however, your monthly bill before and after solar install will tell a lot about how efficiently your solar system is.

Month to month the solar panels have decreased the average daily Kwh by about 8-9KWh - very disappointing. We had quite a cold winter in jhb and the kids homeschooling for prolonged periods with heaters running mean that in the depths we used more power than average.

you mentioned smart grid tie, why is this not feeding the grid directly? depending on where you live, there are different rules, you should also be able to do grid tie limiting where the inverter never exports, I'm asking this because you mention the pool pump tripping your inverter which sounds like the inverter is trying to supply power directly and not acting as a grid tie inverter, since your batteries are likely gone, your solar system @ 2.7kw is all that is likely available and therefore it trips as your 1.1kw pool pump likely draws way more on startup.

All the power on this phase goes through the inverter - sometimes up to 9-10kW - the pool pump tripping the inverter seems independent of the current load on the inverter - so I think it is 'smart'

 

[TheChamp]

Ta.
The batteries are Mixtech EFB 12V deep cycle - Theyre flooded batteries I guess this means lead acid..
There are 8 - and at the moment the inverter shows them at 50.6V - looking back on the last 14days voltage never went above 58V and 100% charge.... Seems that there may be an issue.
The Victron Smart Solar MPPT 150/100 inverter is set to optimize (with battery life).
It is also set to put DC PV back to grid but not AC PV? - I live in Jhb (city power) - not sure if we can send back to the grid..

It's a bit daunting..

Even if you can send back to grid, sending back DC into an AC grid sounds scandalous.

 

[B-1]

With geysers its easier to heat more water than have more batteries. If you buy another 200l geyser and make that the primary and then feed it from the solar geyser so it gets warm water instead of cold running it off solar and batteries will be way easier. Also set it hot so you use much less hot water when showering.
An option is to keep the victron for electronics, lights, appliances and then get a 8kw sunsynk to run the geyser, pool pump etc.

 

[itareanlnotani]

Ta.
The batteries are Mixtech EFB 12V deep cycle - Theyre flooded batteries I guess this means lead acid..
There are 8 - and at the moment the inverter shows them at 50.6V - looking back on the last 14days voltage never went above 58V and 100% charge.... Seems that there may be an issue.
The Victron Smart Solar MPPT 150/100 inverter is set to optimize (with battery life).
It is also set to put DC PV back to grid but not AC PV? - I live in Jhb (city power) - not sure if we can send back to the grid..

It's a bit daunting..

Thats likely way too low.

With lead acid, you really don't want to go below 50% discharge, as lifetime is shot quickly after that.
30% discharge is really where you want to be with lead acid if you want any kind of lifetime.

I couldn't find a data sheet, as Discover Battery don't seem to want to publish one, so I can't really recommend what the minimum voltages should be. I'd guesstimate you don't really want to go below about 53v though if you want any kind of lifetime on those.

Additionally, those batteries appear don't appear to be for solar, at least assuming i have the right link - https://discoverbattery.com/products/sli-batteries/flooded-start-stop-batteries-mixtech-efb/M748-EFB



MPPT controller from your panels is victron 150/100 - those are decent, I have that one too.
What inverter do you have?

The inverter will take DC from the batteries and make AC for the house.

The route will be something like -

Panels -> MPPT -> Battery -> Inverter

Again, some photos will probably help here.
Do you have VRM access to the settings? i.e online?

 

[mrb13676]

I have VRM access but I'm not sure if they are to the full suite of settings...
I can access the color GX controller remotely

 

[itareanlnotani]

Ok, so you have the all-in-one unit.

You can check the discharge voltage on the CCGX - what is that set to?
There will be a few voltage settings, we're looking for the one where its set to stop using battery.

Do you have a data sheet for the battery anywhere?

 

[Kawak]

I have VRM access but I'm not sure if they are to the full suite of settings...
I can access the color GX controller remotely
View attachment 1217196 View attachment 1217198

It looks like your system is a hybrid system, not grid tied, you are basically limited to 5kva on this phase. Explains how the pool pump trips the inverter.

For your system, to fully take advantage of solar power, you must either move things around the phases to ensure things that can be timed to run during the day and your lights and a few plugs (in my case, I started my system with my TVs and later added fridges). Or, get enough batteries so you are still using solar late into the night.

I know many on city power feeding in, so long as they don't end up with a credit at end of month. You also need to be sure that you have an old spinning disc meter, digital and prepaid meters may charge you feeding back into grid.

I think you have 2 choices, plainly put, batteries will likely cost in excess of R50k, a grid tie inverter will cost close to R10k with another R17k for batteries to ride load shedding. We do not know how the legal side of grid tie will be in the future. You may also want to decide if you will ever be going off grid, at your current energy use, going off grid will be costly, you may want to look into your energy usage, there are many places that you can still save significantly without much compromise on lifestyle.

 

[one poster]

On my HA energy dashboard the big consumers still are the geyser and pool pump (1.1kw but seems to run at 600W once running).
The tribe of the long hair insist on hot water being available in the morning up until 9:00 (and then whenever they feel like showering.…)
It kills me to see solar power not being used during the day - on a good day we can generate 2800W but if it’s not actively being used it goes to waste.
I have tried to connect the pool onto the phase that has the solar but it trips the inverter.

Before spending money first make sure your system is installed/set up correctly giving you everything it can. I don't think the inverter should "trip" (the inbuilt MCB's on the EasySolar tripping, or the inverter shutting down in an overload state?) with the pool pump connected (even with ~7X inrush current on start). While inverting, it is limited to 5kVA but when AC in (eskom) is available it should be able to have much bigger loads connected and supplement whatever the solar is not providing from Eskom (if you are producing an ideal 2800W from solar, and using maybe 1000W in the house, the remaining 1800W could be routed to other loads, or if you are only producing 100W from solar the house loads and the pool pump will be supplemented by eskom/your batteries - this is an ESS type setup). The victron ESS setup can be quite finnicky to set up optimally at first (you will for instance want the pump on the correct ACout of the inverter so you don't have your batteries trying to power your pool pump during loadshedding and if not already part of the system you may need to add an energy meter into the system).

If it is the mcb tripping maybe the mcb is wonky or not suited to the inrush current of the pump.

Many knowledgeable folks on mybb but maybe ask for input on your current system setup on energytalk (fair amount of victron expertise there) or powerforum also an option.

Btw, check that you are not running your pool pump more than required (many people set the timer once and never look at it again / have exactly same run time in winter when no one is using the pool etc.). -> one possible place to cut back on unnecessary electricity consumption.

My 2c on DC solar pump is that it is bit of a one trick pony compared to a grid-tie inverter (when the pump is off, other loads on the same phase can still benefit from the grid-tie).

 

[mrb13676]

Before spending money first make sure your system is installed/set up correctly giving you everything it can. I don't think the inverter should "trip" (the inbuilt MCB's on the EasySolar tripping, or the inverter shutting down in an overload state?) with the pool pump connected (even with ~7X inrush current on start). While inverting, it is limited to 5kVA but when AC in (eskom) is available it should be able to have much bigger loads connected and supplement whatever the solar is not providing from Eskom (if you are producing an ideal 2800W from solar, and using maybe 1000W in the house, the remaining 1800W could be routed to other loads, or if you are only producing 100W from solar the house loads and the pool pump will be supplemented by eskom/your batteries - this is an ESS type setup). The victron ESS setup can be quite finnicky to set up optimally at first (you will for instance want the pump on the correct ACout of the inverter so you don't have your batteries trying to power your pool pump during loadshedding and if not already part of the system you may need to add an energy meter into the system).

If it is the mcb tripping maybe the mcb is wonky or not suited to the inrush current of the pump.

Many knowledgeable folks on mybb but maybe ask for input on your current system setup on energytalk (fair amount of victron expertise there) or powerforum also an option.

Btw, check that you are not running your pool pump more than required (many people set the timer once and never look at it again / have exactly same run time in winter when no one is using the pool etc.). -> one possible place to cut back on unnecessary electricity consumption.

My 2c on DC solar pump is that it is bit of a one trick pony compared to a grid-tie inverter (when the pump is off, other loads on the same phase can still benefit from the grid-tie).

Thanks. Yeah, it's the MCB tripping not the inverter shutting down.
Pool pump runs 6-7h per day in summer to take advantage of the solar heating.

Will ask on the other forums but I suspect what is needed is someone who actually knows their stuff to come and have a look. My suspicion is that a whole lot of electricians are now "solar specialists" riding the wave - judging from what folks here say it seems like we had one of these and now have a system which is unsuitable....

 

[mpdjhb]

what is the rating on the victron - I have the 5kva and that should run at close to 8kva for 30 mins. I dont think we have ever drawn that much in the house. Even a 3kva should not trip that easily. Maybe the issue is something other than power draw (earthing? not an electrician!)

 

[itareanlnotani]

The equipment is fine - the Victron EasySolar 5kW is fine for most peoples usage.

The 5kW Victron can peak at 8kW, so the pool pump shouldn't be tripping it.

The storage on the other hand... hmmm. I definitely would not have gone with Lead Acid though at this point in time, and especially not batteries not designed for Solar use.

As you have the Lead Acid anyway, lets rather concentrate on setting the values to more correct settings so that you can get another year or two of use out of them vs replacing immediately.

My probable suggestion in that you should set the cutoff voltage to somewhere around 52 or 53v in the Victron settings.

This will reduce the amount of time you can run during load shedding, but its cheaper than just buying new batteries immediately.

Again, it would help if you can tell us the current settings in the CCGX so we can advise.

I still stick to my suggestion that you look at a variable speed pool pump. This makes far more sense than a "solar" pump, especially when you already have the solar equipment in place - i.e. your inverter and mppt.

Solar isn't "easy", you need to spend a bit of time customizing for your use patterns. It's not hard though.
I'll agree there are a lot of people out there with little to no experience who don't know what they're doing.

I've been offgrid for > 10 years, so I have some degree of knowledge, and I also installed my own systems.
I don't know everything, but I know enough

 

[mrb13676]

Not sure which settings you need. Current settings that I can see:

DVCC off

ESS:

• Mode: optimised(with batteryLife)
• Grid Metering: Inverter/Charger
• Multiphase regulation: unknown
• Minimum SOC (unless grid fails) : 100%
• Active SOC limit 100%
• BatterLife state: Self-consumption
• Limit Charge power: off
• Limit inverter power : off
• Grid setpoint: 50W
• Grid feed-in
  • AC-coupled PV - feed in excess - on
  • DC coupled PV - feed in excess off
  • limit system feed in - off
  • Feed-in limiting active: NO
• Scheduled Charging - none set up

Does this help?

 

[one poster]

The equipment is fine - the Victron EasySolar 5kW is fine for most peoples usage.

The 5kW Victron can peak at 8kW, so the pool pump shouldn't be tripping it.

/

I still stick to my suggestion that you look at a variable speed pool pump. This makes far more sense than a "solar" pump, especially when you already have the solar equipment in place - i.e. your inverter and mppt.

/

seems like the tripping is the EasySolar's MCB (possibly RCD?) that is tripping so does not relate directly to inverter/solar/battery capacity (i.e. it is like a normal multiplus feeding a DB and a breaker on the DB trips when the load is connected). (trip curve of the RCD / MCB a problem?...multiple inductive loads on the same breaker?).

assuming the day time base load is covered when PV production is good, then being able to add more loads, like the existing pool pump, that can benefit from excess PV will already help reduce purchased electricity even before looking at VFD pumps etc?

Think OP needs to clarify goals and budget.
(purchase less electricity) != (spend less money)
(purchase less electricity) != (use less electricity)
Weighting for loadshedding preparedness

Thanks. Yeah, it's the MCB tripping not the inverter shutting down.
Pool pump runs 6-7h per day in summer to take advantage of the solar heating.

Will ask on the other forums but I suspect what is needed is someone who actually knows their stuff to come and have a look. My suspicion is that a whole lot of electricians are now "solar specialists" riding the wave - judging from what folks here say it seems like we had one of these and now have a system which is unsuitable....

not necessarily. But do agree a decent look-over from a good installer and maybe some quick training is not a bad idea. (a reputable installer should be able to monitor your system remotely to help troubleshoot).

Looking at your posted settings, for instance the "AC-coupled PV" setting -> unless you also have an **additional** grid-tie inverter in your system, you do not have AC coupled PV to feed in. The EasySolar's own solar MPPT should actually be what is named as "DC coupled" (does not mean it pushes back DC to the grid - it is just Victron's naming convention). Also the "grid setpoint" of 50W will largely prevent any feedback to grid in any case (the system currently aims to always use 50W from the grid regardless how much PV is available - this type of setting might be needed if you have a prepaid meter that has a tendency to trip when it detects reverse current). None of these settings should really affect the pool pump tripping or purchasing much less electricity but could suggests the system was set up by someone not fully familiar with Victron's ESS.

 

[mrb13676]

assuming the day time base load is covered when PV production is good, then being able to add more loads, like the existing pool pump, that can benefit from excess PV will already help reduce purchased electricity even before looking at VFD pumps etc?

Think OP needs to clarify goals and budget.
(purchase less electricity) != (spend less money)
(purchase less electricity) != (use less electricity)
Weighting for loadshedding preparedness

So the tripping may be due to the pool pump not being connected to the AC2 out but rather to the AC1 out in the (remotely located from inverter) distribution board.

The budget is not huge but would like to scale. Goal is to buy less electricity in the long run (AND to use the purchased electircity more efficiently).
Mostly I'm disappointed with the outcome of the solar install in that it seems to be hobbled by bad batteries/poor setup parameters - it would be great to be able to generate enough to cover baseload during the day, charge some batteries which would cover the majority of the non cooking load at night and then be more efficient with hot water use.

System has be be scalable for eventual off grid use but that is long term.

 

[one poster]

So the tripping may be due to the pool pump not being connected to the AC2 out but rather to the AC1 out in the (remotely located from inverter) distribution board.

As long as eskom is available and the individual breakers on the EasySolar are not overloaded/shorted (AC1 should have 2 x 16A and 2 X 10A breakers; while AC2 is 1 x 16A breaker) - it should be immaterial whether the pump is connected to AC1 or AC2. But if the pump is connected to any of the AC1 breakers it would mean that if AC-in fails, the solar and/or battery will have to carry the load. If it is connected to AC2 and eskom fails then it will just not have power until eskom is back.

 

[one poster]

TL;dr
The system can do more but you need to learn more (or have someone else do it for you). Sort out the pump tripping, optimise your existing system - then improve overall energy efficiency.

@mrb13676 I had a look at your original post in this thread and some posts on powerforum.

Your system should be able to do most of what you want - especially to use more of the available solar that goes to waste at times (to for instance help run the pool pump) but you will need to do a more thorough familiarisation or get an installer to do the tweaking and monitoring if interest/time is a problem. (you are either a passenger or PIC.... PIC will allow you to do way more but requires at least additional knowledge).

To start the ball rolling:
If you do not know, look into why it is suggested to not discharge lead acid batteries below 50%. (btw, I don't think your batteries are necessarily kaput if they are @48V when they have been discharged - if permanently at that voltage it is a different matter). If the batteries do not last long enough during load shedding your battery bank is likely undersized for your usage pattern (i.e. get more batteries or switch off some stuff when you have load shedding - in lead acid batteries you actually lose total battery capacity in relation to the size of the load).

Basics about your system:
In a basic solar/inverter type system you have an inverter/charger, a battery, a MMPT solar charge controller and some solar panels (for most domestic applications the inverter will have input from eskom that connects to the inverter and the output from the inverter will go to a DB and from there to plugs, lights etc.).

In victron systems the inverter/charger is normally one "box", and to that you add a battery, and a separate MPPT/PV panels. The Easysolar that you have they combined the inverter/charger and the MPPT **and** an "outgoing" DB into one enclosure. I suspect your pool pump tripping has to do with the breakers on this outgoing DB and is not related to inverter/battery/solar capacity. If you can get the pump tripping solved when connected to the inverter you should be able to have solar power at least contribute some power to the pool pump when the solar is not used for powering lights and/or other appliances.

I suggest start reading this post and then work patiently through that thread from the top - grit your teeth it is like herding cats at times but it should give you an idea of what your system should allow. Look here for a sense of some more complex tweaking and possibly involving HomeAssistant.

When your system is optimised, look at options around efficiency (VFD like mentioned by @itareanlnotani, heat pumps mentioned by @Jaws677, and smallish grid-tie mentioned by @Kawak). Heating (water, environment, cooking) is to my mind more problematic when aspiring to go off-grid since the battery cost can add up quite a bit. I would look at options like closed combustion woodburning fireplaces for one option to reduce home heating cost in winter.