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3 hours ago, Jan-Hendrik said:

Hi guys,

I have been looking at solar PV system mostly a hybrid system, but my munic will force me to another tariff structure that will make it not profitable for me. 

As noted by others this might only apply if you choose to feed back to the grid. Also as mentioned feeding back in terms of "selling" to the municipality seldome makes financial sense.

3 hours ago, Jan-Hendrik said:

The one thing I noted was that you need to inform your munic if you want to do a solar installation - grid connect or off-grid. But here I want to do something in-between.

I think you can basically differentiate 3 types of installs/applications

1) the eskom grid part of your home and the solar part of your home are in some way connected (even if technically "separated" by a transfer switch) - and you want to sell back excess power to the municipality. = most complicated process and one that requires approved inverters, fancy electricity meters etc. (that get installed at your cost most of the time).

2) the eskom grid part of your home and the solar part of your home are in some way connected (even if technically "separated" by a transfer switch) - and you do NOT  want to sell back excess power to the municipality. = probably exacly as complicated as option 1 in terms of application/permission process but you should be able to remain on a more sensible tarrif and *potentially* keep your prepaid meter.

3) the solar part of your home has no way to ever come in to contact with any part of the eskom/municipality grid. = simplest process but still need to inform municipailty and usually supply an electrician signed off COC that the install meets all national and local install rules.

2 hours ago, gooseberry said:

as long as you don't feed back why can't you keep your prepaid meter?

Even if the municipality does not force a change, there could be a problem with the meter actually tripping. @Bobster's meter goes a bit strange but other meters will trip during a slight unintended feedback (happens when PV is powering a big load that then suddenly switches off - Inverter is slow to respond and for a short while some power is fed through the meter which most will consider as a tamper type event).

12 minutes ago, Dirkie Crous said:

The change over switch was on ESCOM/ utility position and not on inverter position. This was done when the second battery was added to the system and not chanced back to inverter after installation. Working fine as it should.  Sorry for creating a big issue for a simple switch position.

Definitely and absolutely no apology needed.  (hope my post/s did not imply any nuisance value of your questions). Thanks for reporting back - I will guarantee you that you are not the first and definitely not the last person to go through this but at least your posts will help someone else to track down their problem 

15 hours ago, plonkster said:

 There is one in Plet for sale right now 

Road trip!

2 minutes ago, plonkster said:

So... yeah there was this story about a guy who went to a fight and then a hockey game broke out... well, we started with batteries, and then I went completely OT. I hope everyone had a good read

 

15 hours ago, plonkster said:

I was looking at a Yamaha GB1 last week (baby grand). 165k. Car Going off-Grid Victron money. Can't Can easily justify that...

Best I can do to almost head back on topic...

13 hours ago, phil.g00 said:

I once looked at pool heating and I was surprised how effective this was, from memory it was something like the heating capacity could be down-scaled 25-30% with one of these.

Suspect lowering convective heat loss is a big contributor of the blankets (blowing on your tea to cool it down vs covering the cup with the saucer and then blowing). In summer it is almost too effective - pool water at > 30 degree C not much of a way to cool down 

find this very useful at times

https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf 

9 minutes ago, Gnome said:

You get remunerated by getting a job, like the rest of us?

...

...  I too  tilt at windmills  

16 hours ago, plonkster said:

Many many German sounding pianos..

the difference between the german sounding pianos and the wannabes being that anything played in the key of G having a slightly guttural quality to it... 

22 hours ago, Stranger said:

To get the best out of the heating panels requires more pump time than is needed to just keep the pool clean and sends my Eskom bill up.

I have a 45 000 liter pool. On roughly 80% of the surface my double garage roof I have (now bypassed) some of these solar "mats" (multiple rows of little black pipes) that are warmed by the sun before the water returns to the pool. I have found a bubble pool cover way more effective at raising the pool temperature. Another major benefit is that I have not used tap water in over three years to top up my pool (do at times add a bit from rain water harvested from the roof) - the cover also helps a bit to keep leaves and crap out of the pool. Just get a cover with a roll up station other wise opening the pool feels too much like a chore. One way to reduce your particular pool pump running time...

If looking at other ways to reduce electrcity costs I found the following when looking at the various options:

1) Variable flow pumps (pump runs slower depending on settings - drawback is that these are quite expensive and you pool cleaner may not work on the lower settings).

2) Purpose made solar (PV) pool pumps (normally a DC motor that will start running slowly when solar output is low and then pick up speed as solar output increases then slow down again as solar output decreases - you basically leave the pump to run the whole day. Again also not cheap. Think the bundupower ones are PV DC).

3) PV add-on options for exisitng AC pumps. (normally some variant of a solar controller and Variable Speed Drive - the Speck systems as mentioned by @Richard Mackay should be a variant of this. Again not cheap). I suspect the specks are actually made by Microcare and sustainable still lists the actual microcare options. I normally try to support local but at the time could not get any response from Microcare unfortunately. 

In the end when I looked at these options the intial cost just did not make it worthwhile in terms of return on investment for me . 

If I was going to look at this now again, purely with an eye on keeping electricity costs down I would look at my options for a grid-tied inverter as mentioned by @Plaashaas.

I would consider splitting my DB and maybe have my pool and kitchen on a "savings circuit" which is fed by a grid-tied inverter which can blend incoming AC (the idea is NOT to export anything to the grid). Having the grid-tied inverter allows Eskom to help start the motor without needing a 5000W+ inverter (which after startup will be running at ~1300W). Having the kitchen on this same "savings circuit" means that at times when the pool is maybe not runnning that my fridges get the benefit of reduced eskom power consumption from the Rxxxx-xx system I installed. I also do not have to worry will my pool motor even work with a VSD, if it does having another component that can fail etc. If some clouds drift past the sun the pool pump does not sound like a learner driver trying to still master clutch control.

Part 2 of my blog:

21 hours ago, Stranger said:

so would I be far off in looking for a 2KW inverter and panels to produce 1.5 or so ?

The major issue is the startup. My 1.1kW pool pump (actual brand name "Quality".....) with a 7A run rating draws at least 30A in the first 100ms (i.e. 30A*230V=6900W). Even though i.i.r.c.  @plonkster started a 1kW pump with a 3kW victron you will likely want to go a bit bigger on the inverter.

unless really wanting all that the sonoffs etc. offer a basic watt/power meter like this could be much simpler to check most plug-in loads...

https://www.victronenergy.com/media/pg/2556-GX_Device_Manual_Venus_GX/en/dvcc---distributed-voltage-and-current-control.html

@Dirkie Crous, curious whether you managed to track down whatever keeps the meter counting?

On 2020/09/13 at 9:42 AM, Ingo said:

Ok, so for anyone finding this post and have similar concerns. I did some tests and the VE.Bus Smart Dongle overrides both Quattro connected as well as GX connected temperature sensors. While the GX sensor was connected I held the Smart dongle in my hand to increase the temperature and the charge voltage started to drop

out of interest and possible completeness for anyone with a more useful contribution that stumbles on this, @Ingo is your system:

ESS consisting of Quattro + Venus GX + Battery + 1 wired temp sensor connected to Quattro + 1 wired temp sensor connected to Venus GX and then also try to add VE.Bus dongle ?

Is this on a (Bluenova?) LiFePO4 battery with comms? If so, why the two external temp sensors even before the VE.Bus dongle is added - does the BMS not provide voltage and temp info to the Venus GX? I am curious about the potential role and conflicts of an ESS system with BMS provided voltage+temp info and TWO extra external wired temp sensors (Quattro and Venus)  and now a potential third voltage+temp source (VE.Bus dongle). Something in the victron manuals leave me with a hunch that a single source of both voltage and temperature (like the dongle) could be bumped up the pecking order over a source that only provides one or the other. Even then, should this override BMS info?

Any other assistants running? @plonkster IF the BMS provides voltage+temp info, I would assume no external temp sensor should influence charge voltage?

43 minutes ago, mrafiq1303 said:

Any recommendations for how I can start tracking these usages?  

I have read about the Effergy units, but not sure how good or accurate they actually are.

I would wonder about your general warm water use patterns. Bath vs shower, duration, frequency, etc. (6 x full, hot baths 6AM-7AM will take some heating where solar benefit could be diminished). 

Parents/you/teens mostly home during day (assuming non enforced Covid changes)? The bulk electricity use during the day will be oddish (barring the pool pump) if no one is home during the day.

Still coming out of winter... electric heaters on big part of the day?

Parents making tea often (boiling a full 2L kettle multiple a times to make 1 cup)?

Check pool pump flow rate spec and pool water volume and see if you actually need 6 - 8 hours (think general advise is to circulate/turn over the total volume of pool water about once in 24h) . When not using the pool during winter it can likely be even less - even more so if the pool is covered (also very good for reducing water loss...anyone remember that thing called drought?). My pool pump is about 1/2 my household electricty consumption.

Something like an effergy can be useful to identify times of increased electricity use. I prefer the basic effergy which is not web based.  Put the CT clamp on the mains breaker in the DB for a week, then use the software to check the graphs for spikes (you might then already be able to identify where electricity consumption spikes correlate with certain events).

If you have the time, then the/a  prepaid meter self can help identify consuming loads.  If daily routine is fairly predictable, then one "standard day" check you prepaid balance units, (switch off the pool pump breaker the night before), end of day check prepaid units, next day repeat exercise but allow pool to run - now you have a much more accurate indication (units and R/c) of what the pool pump consumes.

If you have a prepaid meter with little light that blinks at a higher frequency the greater the power use, then you can switch off circuits in the DB to see which circuit (geyser / / living room plugs / etc.) contributes greatest to the speed of blinking. Will give you an idea whether maybe the PC running in the study the whole day is using more electricity than you thought.

3 hours ago, Jatho said:

I cant imagine that it would get very hot, its rated at 40A so its running well below its threshold, I'll let it run for an hour today and then go measure the temp with a probe, 

Maybe not a bad idea. Like I said, Murphy knows where I live, so I err on the side of caution..... same reason a MTB with only half a fork makes me nervous 

the sonoff people also try quite hard with the basic R3 to ensure that you must be really motivated to tinker with it with that double decker PCB setup..

10 minutes ago, David27 said:

besides of course this particular one that has some minor faults. 

Not necessarily faults. Actually occured to me that the most likely source of that idle consumption could be the fan/s, but I must say I doubt I would notice a 0.5kWh increase in daily electricity consumption! 

Hopefully some of the members with kodaks, axperts etc. will have more clarity on the frequency of the fan coming on. (also have a look through the forum for topics like Axpert inverter settings, Axpert and Pylontech etc. to get a comparison of what kind of settings/options there are and how that compares to this particular install)

slightly off-topic, but I suggest familiarising yourself with the CoCT approved inverter list, SSEG requirements etc. before hooking up inverters and PV for a client - when PV gets added into the mix where Eskom/City of Cape Town utility power is also involved the levels of complexity/rules etc. go up quite a bit.

hang in there!

@David27, had a look at some of your other posts and seems like you are quite new to the solar/inverter thing but know your way around conductors and such but are in bit of tight a spot. So my quick 2 cents.

with the inverter currently running basically as a UPS there are a number of things that can still affect the inverter drawing power but you will likely need to post some of the current settings for those more knowledgeable about the Axpert type inverters (which I am not) to identify what (if any) the actual problem might be. 

Most likely the 0.4kWh is the inverter's idle consumption to keep itself going (maybe explain to the client that in the absence of solar power the inverter is still powered from eskom to "stay awake").  It could be things like a battery voltage settings that continually keep charging the batteries. The inverter might actually be set up to use the grid more easily than you think. If the grid is unstable (voltage/frequency) the inverter possibly disconnects from the grid and starts inverting for a while (even if power does not actually go off) and then charges the batteries (probably very unlikely at that small consumption level).

Unfortunately I have no idea how often the fan will come on, if at all, while "idle".

I suggest posting more detailed info about the install (single / three phase, inverter settings like SOl, SBU etc, any other peripherals (ICC monitoring/control), install location (small unventilated cupboard under the stairs) etc.

23 minutes ago, Coulomb said:

Miskien te streng, jammer. 

At first I thought to suggest as penance that you have to read a Jodi Picoult novel before you are allowed to read more firmware () - then I noticed that I actually referred to a 3000kVA fictional inverter to power a couple of residential CCTV cameras... so it is more appropriate that I stare blankly at some firmware for a while and then also read a Jodi Picoult novel for all the bad thoughts while staring at said firmware.

You sir are correct. Units matter. The end. 

19 minutes ago, Ingo said:

Well, the datasheet doesn't specify a specific voltage for standby, it just gives a range. Yes it will work on 13.8V but the recommendation from Bluenova support suggested 14V. I also wanted to use 13.8V initially, and will probably do that in future because like you said, this is a standby battery after all. The downside is that I will never get a Low Batt warning on my system, it's calibrated for lead-acid but I can live with that.

Edit: Here is a quote from Bluenova "The rated charge voltage for the mobile power series batteries are 14.2 V for the bulk charging and 13.7V for the float voltage."

My batteries are also bit of test case. Off-topic, but bluenova info does vary a lot - maybe because the internet has a long memory. Bluenova actually have a "customer self service portal", where you can access battery manuals etc. and the "MPS series" guide from there shows 13.9V float

any case, I will see in time what happens (and if I start messing with the charging circuits I know the magic smoke will be released from somewhere...)

15 minutes ago, Ingo said:

... I think it was initially 13.6V for the lead-acid batteries. While doing that I increased it to 14V just to be safe and that the internal BMS can happily balance the cells when needed.

temporary hijack.. thanks for the balancing voltage info. Is your alarm in essence now floating at 14V? I decided to be happy with a 13.6'ishV since the alarm battery is actually used very little (truly a "standby battery") so spends majority of the time floating. Wonder which will have the most effect on shortening lifespan - not balancing often or sustained higher voltage?

On 2020/09/10 at 5:15 PM, Jatho said:

 pretty tight fit in the box 

Wonder how warm/hot that relay gets when powering the geyser? Bit bigger box could maybe be safer? Pic is obviously not final install position but if tempted to just toss the box ... (sounds wrong!)... next to the geyser - the closet sparky in me thinks MCB's are generally not rated/approved for any position other than vertical... 

8 hours ago, Kiranbhowan said:

Hi can anyone advice me on lithium batteries. I have 2 lithium batteries 12v 7.5 amp hour for my 24 volt garage motor I need to connect in series to get 24 volt , but I have read that it is not advisable to connect lithium batteries in series , I need to use a bms to connect please advice how to connect and where can I find a bms to suit my project 

First poviso: Safest is to check with the manufacturer/supplier. If you are in sunny RSA I assume you are referring to the "lead acid drop in replacement" type LiFePO4  batteries - locally bluenova or freedomwon (based on 7.5 as opposed to 8Ah most likely freedomwon). The batteries can be connected in series or parallel. The batteries should already each have an internal BMS to protect against over/under voltage, short circuit etc. so you do not actually need a BMS - you could however need a battery balancer to help prevent the individual batteries to become too "out of sync" in terms of charge levels. Without the balancer you likely will not blow anything up, but the total life time of the batteries could be lower

This is the bluenova info I have in terms connnecting series:

For Series configuration preparation:

11 hours ago, Richard Mackay said:

I'm always amazed by the predictive text on 'smart' phones. You go back and read your message which isn't what you intended..(but hopefully the recipient is smart enough to reverse the predictive text algorithm and get the message!)

Know what you mean. Gets even more fun when having multilingual keyboard options and forgetting to change the language before starting your message..

but trying to set an example for political leaders the world over, I can unfortunately not blame anyone else or even my phone - mistake was all mine 

36 minutes ago, Coulomb said:

I think you mean 3 kVA. Units matter.

have a heart, we are still adjusting to the shock of having electricity for two days in a row and now you want us to use correct units and technical lingo. Je bent een strenge leraar (if I recall correctly from a previous post you have some non-Aussie lineage) . 

... I actually just realised considering current world events (movements?) that "Units matter" can actually go in a whole different direction as a conversation and even if tongue-in-cheeck will likely get me banned, so back on topic and to upset the more technically inclined: @JustAsking 3 kVA is 3000VA...which is sort of like 3000 Watt (or 3kW) - it gives you an indication what the maximum load is that the inverter can power (you size an inverter for the peak load that you expect - not the average load).

1 hour ago, Tariq said:

Oh, did not know that, I thought it was about R289 for CoCT , as we are already paying a basic fee of about R160 plus the R120 odd for feed in

No man, slaapstad already has the mountain and almost everything else - you guys can't also have the highest basic fee - leave something for the rest of us  (was totally unclear from my post but the R429 is not for CoCT... aim a bit west...EDIT: mean east)..

at one stage it appeared to me that google indexed more documents/conference/indaba info about setting SSEG tarrifs and the impact on municipal revenue than info about technical standards and incorporating SSEG to the grid.... anyone bored enough can scan through here for instance

59 minutes ago, plonkster said:

yeah... a light year is distance , not time*...

maybe relative to a leap year it could also be a normal year...  aaahhh a normal year...would be nice to have one of those again..

* we are not getting into the math of time it will take to travel 4 light years..