SilverNodashi

You can put a ball valve at the top of the JoJo tank, to automatically top it it up from Municipality, and then run your house directly from the tank. If the water pressure is a bit low, install a 3bar pressure pump

How are you connecting the Pi to the Mac?

Yes, you cut the plastic on those tabs away to get a cable in.

I know some companies charge between R2.5 and R4 per Watt.

I can help you, what exactly are you looking for?

In a DC system, it's perfectly fine to "break" just one input. + is normally broken, though - can be broken as well.

Solar regulations require that we "break" both though. You need to put fuses in for protection, and then an isolator to safely switch disconnect the PV array from the MPPT in case of emergency.

3 minutes ago, georgelza said:

ye, we brought in foreigners that don't have the local experience, like the foreigners that design the pulveriser, like thee foreigners that designed the boilers.

it's more a case, use the foreigners, but blend their input with local, long term experience.

G

I meant, us / we, those of us with solar systems  

4 minutes ago, georgelza said:

hope this gets to someone with his finger not to far up his ass to realise there is skills in this country that is clearly willing to share their local experience to fix this f up.

G

But we're already busy fixing it

On 2019/05/09 at 8:00 PM, The Terrible Triplett said:

Get some Pylontech banks - they last decades - 6000 cycles. 

I think a supercap will last longer? 

1 hour ago, NigelL said:

I totally follow your reasoning - I went through the same thought process before deciding to install 3 x 330W panels in series with my 150V MPPT charger. However, I am in Cape Town so am not exposed to the same cold. My roof is also North-West facing, so only gets a relatively low illuminance first thing in the morning.

There is always the "worst-case scenario" where one has an unusually cold weather/snow event at mid-day and your batteries are full so are not pulling any current from the MPPT.  You then need to weigh up your appetite for risk versus the higher priced 250V MPPT .

A famous saying comes to mind "In theory, theory and practice are the same, but in practice they are not". It may therefore be worth doing some tests with 2 panels in series to start off with.

I prefer to cater for worse case scenario's as well. We can't control, not predict erratic weather and I would rather be safe than sorry in this case. 

On 2019/05/07 at 8:17 AM, Johandup said:

In the case of a hybrid inverter, yes.

Grid tie inverters, without batteries.  do this as well. It will, for example, feed the full 2Kw PV available into the grid. If the house needs 2.5Kw, the remaining 500w will come from the grid. 

On 2019/05/01 at 10:08 AM, plonkster said:

Mmmmh, so this topic made me do a bit of research into the topic again.

Cheapest reasonable i3 in Cape Town right now, around 400k. It has 65k km on it.

This would be likely be the second vehicle in the house. No way I'n doing Namibia trips in an i3 even with Rex.

Monthly payment over 60 months would be around 10k with no deposit or balloon (balloons are evil). That is too much.

But I can trade in the Suzuki if I can convince the wife (I probably can), so I can put down a deposit of 60k, so that's 8k a month. Still too much to my mind.

I could probably throw another 100k into deposit, now we're around 5.7k a month. That's getting there (but I'm in for the opportunity cost on that 100k, so technically I'm still above 6k a month).

Now if I could get the purchase price down to around 250k... well hello, now the monthly repayment is more like 3k. This car is going to do 5000km a year. So we're below R10/km (meter taxi rates) at least as far as that goes!

And then you need to install a nother R150K solar system to charge it

On 2019/05/01 at 10:14 AM, admiral said:

At "least" the cabling between the garage sub db, and the house db, will only be for 220v AC - not the 48v DC! 

Now, imagine that expense!

On 2019/04/18 at 12:54 PM, Youda said:

Couple of weeks ago, I just switched my battery bank from 20kWh Winston to 4x Pylon US3000, 14kWh total. And these are the parameters that are working okay for me:

C.C. = 52.5V
C.V.  = 52.0V

No unexpected shutdowns are occuring, batteries are being charged to full, no auto-draining of the battery when it's in the C.V. state.
I will monitor the batteries over couple of months, whether the cells will start to be unbalanced on not. If not, I will stick to this lower charging voltage as I prefer longevity rather than stretching the capacity of the batteries to it's limits

This is quite valuable information. For both the Victron and Voltronic inverters, the manuals state that float voltage should be 53.0V or 53.2V respectively and not 52, or thereabouts as you say. 

On 2019/05/06 at 4:59 PM, Travis said:

I'm surprised to hear that others do't get peak power from their panels.

 

I am using Solar Frontier 170W CIS panels and consistently reached and exceeded their rating. I used to have 12 x 170w (2.04kw) and would produce 2.4kw around 11AM often.

Now I have 20 x 170w (3.4KW) and consistently run into the 3KW capacity of my Inverter. Even going into winter. Looking at my logs I was peaking at 3.2KW as little as a week ago.

When solar charger is running I can hit 3.7KW at 11A.M.

 

Most power I have seen from the panels is 4.6KW at midday on a cloudy day in February where I was charging batteries and 25Amps and using 3.1KW from the inverter. Exactly as described above the sun came out from behind the clouds and panels lapped up the sun at 230W+ each of their 170W Rating. 40% power gain for a few minutes.

https://pvoutput.org/intraday.jsp?id=50630&sid=46057&dt=20190212

Luckily thugh that exceeds the Watt rating of my inverter, it did not exceed the DC AMP rating and nothing released smoke..

 

These Japanese Thin Film panels never ceases to impress me.

In all honesty, thin film panels, like the Solar Frontier panels are designed completely different than Monocrystalline or Polycrystalline panels and generally perform much better. Since they're more expensive fewer people use them. 

13 hours ago, Riley said:

1600w peak on your inverter means it won't break just because the normal 800w happens to go up for a few seconds, but you sure don't want to run it at peak for a matter of minutes. If it's rated at 800w continuous, then your microwave better be rated for 500w max.

A microwave's input is often 2x it's rated output. That 500W microwave night use 1000W or perhaps 900W to run. 

On 2019/04/29 at 11:53 AM, CarlT said:

I see ElectroMechanica also does the Hager DB and CB's : http://www.em.co.za/Home/Distribution-Boards/VS318TJ.html

Does anyone have experience with them? I want to get this one. It is completely oversized for my application, but I have a lot of wall to work with, and would rather have too much space instead of too little...

Those DB boards are rather sturdy and I prefer them over the cheaper ones at Voltex or ARB. They're a bit more expensive but very good quality. 

7 hours ago, Youda said:

The most accurate way is to buy a very small PV panel with a defined Wp and the same crystaline technology like the one that you are using for your main PV array. 10W panel is more than enough.

Place the panel at the same direction and angle (important), like your production panels are.

Then attach a big resistor that will cause this small panel to work near it's maximum power point aka MPP.  The truth is, that MPP does move just a little, regardless of insolation/ Therefore a resistor is a sufficient load simulator and MPPT controller is not needed.

Next, you just measure the Volts x Amps with an Arduino. This will give you a maximum available power at the moment, which can be just multiplied, in order to predict main PV array's potential.

Similar approach is sometimes used in the solar trackers:
 

Just keep in mind that that a  36 cell (10W) panel's efficiency is generally much lower than a 72 cell panels

5 hours ago, Youda said:

@The Terrible Triplett

Hmm... if the box runs 24/7/365 for 8yrs, then why the hell are you opening the case to see the stickers on the mainboard? To sweep the spiders?

 

He probably has to jump start it on cold mornings. 

On 2019/05/06 at 8:01 PM, Youda said:

Hi @Basil Katakuzinos

I'm using InfiniSolars 5K in my system ( https://powerforum.co.za/topic/2322-youdas-off-grid-lab/ )

InfiniSolar 5K Plus
+ Electrically it's great and I can push it to full throttle for hours.
+ It's cheap.
+ Has a lot of features and can work in grid-tie and in off-grid modes too.
+ It's all-in-one, thus simple operation and install.
- It's all-in-one, thus complicated inside.
- SNMP card is crap.
- InfiniSolar has a quite high self-consumption, aprox 125W.
- Technical support is poor and the manufacturer does not care about your problems.
- Some people experienced repetitive failures with all kinds of InfiniSolar inverters.

Victron Multiplus (II)
- Is just Inverter/Charger. Therefore, you will need to add a couple of MPPT controllers to it, typically Victron BlueSolar.
- Also, you will need to add a "control center". Like Victron CCGX or Victron Venus.
- A bit more expensive.
+ The build is simple and robust.
+ There's a very few reported failures of Multiplus when compared to the other inverter brands.
+ Self-consumption is very low.
+ The support is good and there's even a possibility to get in touch with the manufacturer (Victron Energy Netherlands), if necessary.

 

If you have the budget, Victron is a better choice. Especially in long-term, as it does not waste too much energy and has a decent support. On the other hand, overall Victron solution is a bit more expensive and there's more boxes and cables to be mounted on your wall. Also, you need to check whether your installer has an experience with the Victron equipment.

This is a good comparison. 

I have to add though that Victron's are rock solid and have a good track record. Though I also know of some Infinisolar's which have been running for 3 years. 

8 hours ago, Tokolosh said:

How would the support be if we can can start a repair center for voltronic ( Axpert, RCT etc) inverters.

I have: 

Contact in China to source the goods and i do frequent visits to China for business.

A workshop with a electronics engineer that is willing to make this happen.

Some funds to trow towards this venture.

I need:

Support from my fellow re-sellers/ installers/ end users/ pretty much anyone and everyone.

The clever ones that have  the brains but not the time to make this happen. ( eg schematics, common faults, parts list)

Maybe more engineers/techies in all major centers to bring costs down.

Did i mention support.

 

So i don't want to make this a money spinner for me.. I have enough on my plate but i feel the need to start this or at least investigate this .. maybe a Power Forum  Repair center if you wish.

We pay the guys the do the work. we try and get the parts in SA as a stock item and make sure we support his to keep it going.

 

Am I alone in this or do i here a Hell Yeah.

Or am I being foolish.. as we SAFARS are known not to stand together and make a difference.

 

 

 

 

Count me in. 

1 hour ago, The Terrible Triplett said:

The stats are against companies lasting more than 1 year, 10 years is respect and more than 10 years, you are good!

So after my fiasco with warranties on Tenesol panels, bleh I say to warranties from new suppliers whom have not been around for longer than their offered warranties.  

And yes, there are exceptions. 

Hands up! Who's Yingli solar panels are still working?

27 minutes ago, Rautenk said:

Be careful of that statement. Again Axpert is allowed to be installed in City of Cape Town, however it should be done as per SANS requirements (basically off-grid installed), This DOES not give you comfort on the having the Grid AC in at all times. 

 

I didn't say it's not allowed to be installed in City Of Cape Town. I am saying that we can't rule what happened in another municipality as the golden rule for all. i.e. the rules of CoCT don't apply to City of Johannesburg, as example. 

4 minutes ago, ebrsa said:

I specifically avoided the issue and reporting on it for the simple reason that I do not want to start a war of words involving Swartland Municipality (SM). Since I represented a community organisation, a ratepayers association in fact and one that is now in its 64th year of existence, meetings and discussions with SM are on behalf of our members in the village. So of course I at times have meetings with the Mayor, the Administration and our councillor. Some of these recently concerned the budget for the next year and we do not agree on some issues. So I hardly need to find more issues where all kind of questions and statements reflecting on the integrity of SM take place as has already happened following my original post on my meeting with our Director Electrical Engineering Services. He was extremely helpful as he always is and gave us more than two hours of his valuable time. So the last thing I wish to do is to see how much I can muddy the waters. Hopefully I have learned at least some diplomacy and wisdom in my 81 years of life.

I will make my own decisions based on the regulations and requirements and if proven wrong will take steps to rectify them. Others must make their own decisions as rules and regulations in other instances may be different with the exception of national legislation.

Not to endlessly belabour the point, let me just, ask how many Axpert owners have managed to feed energy into the grid and what was the result. I wonder if anyone so far has succeeded in doing so and whether their Axpert survived the occurence. Certainly it seems not to be an issue in Australia or @Coulomb and @weber would most likely have reported it.

Y ou did reply to my example of cars rolling over and killing people, to state that the aggrieved party would have a claim against the manufacturer. My example and other questions were actually to see if someone would come up with answers to explain the issue of off-grid inverters, the input of which is connected to the grid. Off-grid inverters are not designed to feed energy into the grid as we all know.

I think it's safe to say that the COCT rules don't (yet?) apply to SM so there's no need to worry about it. At least not at this stage?

3 minutes ago, The Terrible Triplett said:

I once connected a 12v Victron inverter to a 24v battery. It worked for a nearly a minute before the room filled with white smoke.

It was sent for repairs - for fun - and the caps where replaced. It worked AGAIN!!! ... for a few months before starting behaving strange.

Then I sent it to Victron. They checked it out and ruled that yes, it can be repaired i.e. a new board, cost being slightly less than a new one, after they spent an hour or so on it.

What I took away from this:
1) Every thing can be repaired but how long before something else fails?
2) Replacing boards are not as cheap as we would like to think they are.

And if I sent the inverter back to Victron day one I'm pretty sure they would have said: We can replace the caps but there will be other damage that we cannot see today unless we spend a lot more time on it, time which is just not worth the costs of the repair as there is NO guarantee to be offered.

The questions one should ask:
So if a inverter is repaired, does it go with a guarantee?
If so, for how long and what will that guarantee cost to offer the client?
Is it worth it?

I'm pretty sure at the end of the day the sums will not be in favour of repairing. Devices today are just not geared for that anymore.

Same here. My mom's alarm packed up so I took it out and see the MOV is blown. Ok, no worries, get a new one and replace it. Get a new one for R10. The trip to the supplier was far more expensive in terms of time and petrol. Replaced the MOV, nothing else looked blown, took it back to my mother's house and reinstalled it which probably took another 40 minutes to rewire everything in the tight space I had to work with. Test it. Same problem exist. I feel the heatsink and it still gets hot and the remove zone still don't work. So now a R10 job suddenly turns into a few hour's and up and drive to figure out what is wrong since we don't even have an alarm in the house. My conclusion, go buy a new alarm, even if cost R1500.