Hi All,

 

I, for some reason cannot post anything. Some "Website blocked". Any ideas ? It seems that I can post in sections, perhaps the posts were too large ? 

 

Seems that, when I linked to other pages on this forum there is some security rule that blocked this. Managed without by posting in 2 chunks (3 with this senseless post, sorry)

Edited April 1, 20197 yr by MorneDJ

Hi All

First, amazing forum, and I support that thread that highlights that a few members should be thanked for their input. Anyway ...

This weekend, after paying my monthly electricity bill, I realized that I am giving money away to Mr. Government. My electrical bill range between R1,300 - R3,300, but normally averages R2,000 pm (data from the last 3 years). It should be noted that most of the accounts show an "estimated" amount, corrected every few months. Average consumption is around 33 KWh per month. I did a quick inventory and realized where I have significant wastage, some issues and where I can reduce that quantity. I implemented some measures to reduce my electricity bill. I also kicked myself for wasting so much money over the years.

I then spend most of the weekend on the net, scanning/reading about 30 different websites and found this website via AVForums.co.za. I think I spend about 20 hours here (including most of this day ... darn), reading most of the significant pages. However, I will be the first to admit that I now know only a little bit, a dangerous thing ...

This weekend I reasoned, if I can install a grid-tied solar system that can do 15 - 20 Kwh per day, I should be able to save around R1,000 per month. That is at least R96,000 over 10 years, and therefore also my budget. I may be able to scrape by a few more cents (lets make the budget R100,000). Where, I yet do not know, but I have two kidneys ... 

I will install a power meter tonight to measure my hourly power use over the next few weeks (after the implementation of my saving measures), and will use the time to plan a system, perhaps adopting the "Victron grid-tied" system as being "designed" on the thread (Victron grid tied setup from scratch.

In the meantime I will get in an electrician to split my DB into "critical" and "not critical" systems (that I can do without during load-shedding or when the batteries are too empty).

I visited the Powerforum store but it appears that it is not yet fully operational, apart from the Polytech US2000 batteries. It seems that the people here can assist in the planning, installation and highlighting where I can find the best deals. While I would love to DIY myself, I also know my limitations, looking back at other projects that looks like I did it with my feet, while drunk ... and blindfolded.

Invertor/charger: While I would love to go for a 5 KW system, I will not be able to stretch my budget that far (only one kidney that I can flog) and I most likely will go for a 3 KW system, trusting Eskom to feed my peaks. Currently I still do not know enough about the benefits and disadvantages of the different Invertors and chargers, whether to go separate (as per the Victron thread) or an all in one invertor (if I can find it at a really good price with a saving of a few thousand), although I do understand the benefits of a separate system. Currently, I have only read good things about the Goodwe, SMA and Victron systems and will likely select one of those going forward. Price and warranty will likely be the determining factor. 

Batteries: I will definitely go for Li-ion, likely the Pylontech US2000 or US3000, depending on which ones I can find at the best price. I think that I will have to make do with 2x US3000B batteries, now around R21,500 each at Re-volt.

Solar Panels: Likely the best bang for the buck, and 12x 330 W (3 parallel with these 4 strings [am I correct with this term] in series) should be more than sufficient to cover daytime use and to charge the batteries. 

Roughly, I am already exceeding my budget and I have not yet included the cost for installation and I really will have to look at the costs, and perhaps scale down to the US2000 batteries, or less panels (9 to allow 3 in parallel, 3 in series). 

Any input, or things that I should look at now.

Where can I save a few rands?

What am I overlooking or missing?

Am I delusional? 

Welcome Morne,

No, you are not delusional, and thank you for making the effort to read the forum, and start where you need to start. 🙂 

When you measure your consumption, check the average usage per 24h and the usage when all is asleep.

Lets us know what you find.

Regarding your kidneys, they pay more for the right one . Lol . Look at a once off purchase on the equipment and not training batteries etc. Decide what youre going to run on the system and will it be within the ratings of a 3kva inverter. It is a good idea to find your day and night consumption to size your battery pack. But your biggest bang for buck will be to cut back on wasteful usage, and possibly a solar geyser or conversion if you don't have yet. DIY can be fun and save some $ but assuming you don't blow thing up in the process. But this is a great place to ask questions before the  costly magic smoke is released.

1 hour ago, seant said:

... before the  costly magic smoke is released.

I've been summoned? 🤣

 

@MorneDJ - you can start with less panels and if you go Pylontech, the smallest one.

With panels, install all the frames and right sized wires (like say 10mm2), to have room to maneuver.

The frames + labour is the inconvenient labour intensive part, you want out of the way.

Focus on the core system to be exactly what you want. Spend the monies there.

4 hours ago, MorneDJ said:

Hi All,

 

I, for some reason cannot post anything. Some "Website blocked". Any ideas ? It seems that I can post in sections, perhaps the posts were too large ? 

 

Seems that, when I linked to other pages on this forum there is some security rule that blocked this. Managed without by posting in 2 chunks (3 with this senseless post, sorry)

Here we go. How to post links:

https://powerforum.co.za/topic/2518-access-denied-logo-error-code-15/

Sincerely

Jason

5 minutes ago, Pietpower said:

While accessories adds another R50k especially lightning protection, solar panel mounts and installation.

We estimate that the frames with parts, cable and installation adds about R1k per panel give or take.

Lightning protection, no idea but from overseas websites it is wot R3-4k per device device?

Combiner box you can buy or build your own at +-1/3 the price of what they sell for using the exact same parts.

Fuses and all that, you can go good yet affordable or nice and expensive - affordable side wot, R2k, aim for less.

So someone may be over zealous in their quotes to you?

34 minutes ago, Pietpower said:

R1k for frames I did not expect

Makes two of us till I saw the amount of parts for just 6 panels, and then the labour. 🙂 

New quote I got for just labour is now  R2150 per day which is quite acceptable for 2 men and their boss.

Fortunately, I avoided electrocution last night installing an efergy energy meter on my mains in. Had an enjoyable few minutes when I tripped the power, still do not know the reason, but I may have suffered a short blackout as I can only remember that blue flash. So, I will definitely make use of an installer. 

Anyway, after recuperating from the short power outage, I revelled in the output of the meter, showing me where I am wasting power. The result was a short family information meeting. I decided not to change the typical usage over the next week, and to start making a few changes next week (energy saving, not more exercise of healthy eating ...) 

Seems that my current, typical night-time usage (22:00 - 06:00) is less than 0.5 kW, with the meter showing less than 0.4 kW for most of the night (0.3 kW this morning). Naturally I took the display to bed to the utter dismay of my wife, but I promised her that it would be a one night stand. 

Will keep on logging the data and provide feedback, but it seems that a 3 kW battery backup should be sufficient for the night after some slight changes in power use. The night-time drain can be traced to:

- A water fountain that was running the whole night;

- 2 or 3 refrigerators that were on the night (not sure of the 3rd one in the apartment);

- A small air pump for a fish tank;

- A media PC that I never switch off;

- A plethora of small lights from chargers, multiplugs, TV's and PC monitors on standby;

- And naturally, vampire drawing from the various chargers located through the house. 

(I live in a secure area and do not need lights around the house at night, so those are always switched off)

 

I have no idea what is running at night in the room of the domestic, but management and a few timers can significantly reduce the night-time draw. 

I like the idea of installing the frames for the solar panels in the meantime. That I can do, will measure the pitch of the roof this weekend. 

3 minutes ago, MorneDJ said:

Had an enjoyable few minutes when I tripped the power, still do not know the reason, but I may have suffered a short blackout as I can only remember that blue flash. So, I will definitely make use of an installer. 

Properly initiated I see. (cwl)
There are a few of us here that has done stupid things, as in really stupid. We don't talk about it anymore - until after a few beers - obviously.

2 minutes ago, MorneDJ said:

Naturally I took the display to bed to the utter dismay of my wife, but I promised her that it would be a one night stand

No it is not and you know it - so does she. 🙂 

4 minutes ago, MorneDJ said:

(22:00 - 06:00) is less than 0.5 kW,

So you found them. I literally went to the DB board and switches all the breakers off. Then, with Efergy meter in hand, switched breaker for breaker on. Worst viper loads we had was 3 x clock radio / alarm followed by a fluorescent tube was converter to LED tube with transformers left in place wasting +-200w when that 10w tube was on. 🙂 

Seems to me you have it pat down so far.

One titbit to add: You can fir the batteries to the load or the load to the batteries.
Quite a difference in cost. Decide what is important to keep on with the batteries.

I was also quite shocked (figuratively) when I figured out where all the power wastage was going. Initially your attention is drawn by the things that draw a lot of power when they are running, but as you say, the plethora of small devices running 24/7 can suck a lot of power. I put lots of things on timers so they only run when the sun is shining, and very little runs from 11pm to 5am.

Seems I cannot work productively, my mind keeps wandering towards the solar installation. Fortunately I have a mind like lightning. Unfortunately, after a quick brilliant bright flash it is all gone. 

So I measured the rooftop area using GoogleEarth, ±56 sqm and around 100 sqm facing directly north. The roof has a weird shape, not the typical A form, almost looking like a dbl story house from the street (south), sloping downward in a northerly direction. It is almost as if the architect planned for a future solar installation 30 years ago.  

The 56 sqm area includes the swimmingpool solar heating mats. Which I want to rip out in anycase, including converting the swimmingpoot to a greenhouse. But the kids still object. This area is important as it is subject to minimal shading, being around 1 - 2 m higher than the 100 sqm area. It excludes the area covered by 2 solar geysers, which I forgot to mention (refer to the comment about my bright mind).

The 100 sqm area get a bit of shade from the higher roof area (early mornings).

I am thinking to start buying the solar panels, frames and the batteries in the mean time, or at least ordering it, considering the state of stock in the country, where possible, making use of any "special offers" available, selecting the invertor, chargers, protectors (etc) once I have decided between Victron, Goodwe or SMA. Am I jumping the gun or should I order so long. 

With the 48V batteries, if I buy one unit now, will it be easy to add a second or third battery at a later stage. 

With the panels, if I get 9 now, will I be able to add additional panels (will likely add 3 in parallel each time) at a later stage. 

27 minutes ago, MorneDJ said:

... once I have decided between Victron, Goodwe or SMA ...

There may be stock issues.

If you are:
Victron is a good choice if you are into data / Linux / scalability / ESS / separate parts if things do go wrong.
Goodwe is a good choice if you don't have the 3.5kw inverter max size restrictions, now, or coming to a municipality near you in the future.
SMA is a good choice but adding batteries can be expensive unless you make the UPS part a separate buy.

So three good choices, boils down to what you personally prefer at the end of the day.

There may be a stock issue here and there after the last drama but in a week or two and there will be stock again. Take your time to decided.

So many questions.

The Goodwe ES 4.6 kW (R29,500 incl) is slightly cheaper than a Victron Multiplus II (±R 30,000 with the trimmings [VenusGX, MPPT, BMV]), and can do about 50% more. How does the Goodwe report on battery charge status, solar generation etc. ?

If I go for Victron system, can I drop in another in parallel to give 6 kW to the house should I ever need it ?

If I estimate that I may need/use 5 kW for the period 17:00 - 07:00 (no solar power), and an additional 15 kW during the day, I would actually require around 5400 W of solar panels to charge the batteries to 100% during the day (assume 5 sun-hours) as well as power for the house. Is this correct ?

As the Li-ion batteries are quite expensive, and I would prefer to make them last as long as possible, I should not discharge past 75 % (should get more than 6,000 cycles, or around 20 years). If the US3000B report to be able to supply 3.5 kW, I should get 2 that must be run in parallel to ensure that I never go below 75% and that I have at least 5 kw of power for cloudy days or long power outages. 

At the same time I would like to reduce my electricity account, so, as the system increase, the cost increase, but the potential benefit in savings becomes less and less. Trying to develop a cost versus savings curve, but that is a battle. 

Highest cost would typically be a off-grid system, saving me around R2,000 per month, or R200,000 over 10 years (not complicating yet with potential Eskom increases, losses in interest etc.) If I decide to go that route, it will cost more than R200,000 to implement, but it may be something that I could consider. In that case the Vicron units, that one can run in parallel would be better. 

Where can I find more information on lightning protection for such a system?

 

 

There may be stock issues, but a lot of this equipment, particularly solar panels gets cheaper as time goes by, better to save and buy all at once. If the demand is there people import crates of panels etc, its only SA that has load shedding after all!

If you are going grid tie, get the inverter first (and one solar panel to play with), get that installed and wired in, then the solar panels. That's probably about 50-60% of the the cost. The other 40% of cost will be batteries which  are easy to install, but an expensive cost as you have to buy all at once, although that is not the case anymore with lithiums where you can apparently add as you go along.

Edited April 2, 20197 yr by DeepBass9

As a matter of interest, what do you pay per kWh currently?

31 minutes ago, MorneDJ said:

[VenusGX, MPPT, BMV])

With Pylon's you don't need a BMV. 

32 minutes ago, MorneDJ said:

At the same time I would like to reduce my electricity account, so, as the system increase, the cost increase, but the potential benefit in savings becomes less and less. Trying to develop a cost versus savings curve, but that is a battle. 

With grid tied, it is a saving from the moment you switch it on. If shaves off all that which the panels can generate from Eskom. It seems to be a little bit confusing, the savings one gets from being grid tied?

The batteries are the costly part for larger loads.

34 minutes ago, MorneDJ said:

... off-grid system, saving me around R2,000 per month, or R200,000 over 10 years ...

Mmmm ... maybe. You can save R2k going grid tied if you do it right, for 1/4 of that price ... spit balling.

Let me explain:
Lets say you have a 3kva inverter, it can do max 2.4kw continuous.

You have 3.4kw panels on the roof, at this time of the day they can generate say max 2.4kw

 

Loads:

Example 1:

House draws say 500w 24/7/365.

No other loads.

Then your Eskom draw is +-10-50w (depending on a setting) - as the entire 500w is coming from the panels.

Eskom looses.

 

Example 2:

House draws say 500w 24/7/365.

Oven is on at say 4kw.

So we a total of 4.5kw draw from Eskom 

MINUS the 2.4kw from the array 

= 2.1kw draw from Eskom 

You save buying 2.1kw from Eskom / they loose.

 

Example 3:

House draws say 500w 24/7/365.

Geyser is daytime on only, say 4kw - and you set it on a timer like Geyserwise, to come on at the right time.

So we a total of 4.5kw draw from Eskom 

MINUS the 2.4kw from the array 

= 2.1kw draw from Eskom 

You save buying 2.1kw from Eskom / they loose.

 

This goes on the whole day. From the 1st watt in the morning to the last watt at night, you save cents and rands every hour.

4 hours ago, The Terrible Triplett said:

This goes on the whole day. From the 1st watt in the morning to the last watt at night, you save cents and rands every hour.

So I’m with you - grid tied FTW. 

If the stove wants 3.5kw and the panels can do 2 well the 2 comes from the panels.

But we are all worried about Eskom and power cuts which pushes towards hybrid with some batteries.  Since grid-tied shuts off when the power goes off as we well know at Black River Park which has an enormous PV system but is just as dark as anywhere else when the grid goes off.

As you know the trick with hybrid for those in Cape Town is a design that satisfies the council.

But as you know I’m trying to do this their way.  So far it’s been an interesting process and I think my design is the better for it.  

But it’s still not clear whether I will need to do a two inverter setup - one for the PV and one for the UPS function.

Still, it’s a process and i’m mostly having fun.

 

21 minutes ago, Elbow said:

Since grid-tied shuts off when the power goes off ...

Yes, it does BUT ... the penny just dropped ... a Victron Hybrid keeps on using the panels to provide all the loads daytime and because the big loads gone, there is a LOT spare ... WHEN ESKOM IS OFF.

Others may not have this, where the panels keep on providing, like Blackriver Parkway.

Kettle, microwave, jack hammer, so what Eskom is off. I have the panels with the base loads running, to not touch the batteries.

Therefor batteries are really only for the night, and then the loads are low in any event.

And that is why I keep on pushing the point of you don't need to go big with inverter and batteries - you can get damn far on a 3kva and a 24v 225ah bank, like I have been doing. 🙂 

 

21 minutes ago, Elbow said:

As you know the trick with hybrid for those in Cape Town is a design that satisfies the council.

It is ONLY because of the batteries on the Victron, not the panels. And they will realise their "mistake" soon because thanks to @Fuenkli we now have two DA members in Cpt and the DA HO asking questions from the senior solar management. 

Send a email to the DA member in your area. Push them.

Edited April 2, 20197 yr by Guest

21 minutes ago, The Terrible Triplett said:

Send a email to the DA member in your area. Push them

I will do that;

And yes, my Infinisolar behaves the same - essentials output continues to be powered from panels and/or batteries in a power cut. I have lights and some plugs on that output.

Meanwhile with grid present it runs grid-tied so the 3kVA size isn’t really an issue.

So it’s a perfect solution.

On 2019/04/01 at 3:43 PM, MorneDJ said:

... My electrical bill range between R1,300 - R3,300, but normally averages R2,000 pm (data from the last 3 years). It should be noted that most of the accounts show an "estimated" amount, corrected every few months. Average consumption is around 33 KWh per month...
 

Hey Morne.

Daily average of 33kWh over 30 days should cost you around R1200, plus VAT. The rest are the network/service charges/surcharges (in my case +- R520+VAT). 

13 hours ago, Elbow said:

As you know the trick with hybrid for those in Cape Town is a design that satisfies the council

I am with @The Terrible Triplett  on this one. I would just wait until they accept the hybrids without the change over switch. I am sure it will happen soon.

 

@FdlSys: Looking at last months account, we used 973 units over 28 days, averaging around 34.75 units per day, costing me R1,734.25 Ex VAT.

 

Very similar to mine so following your journey with interest:

948 units over 26 days giving 36.46 units per day. Pure line item cost was R1224. The other 800 or so are the charges & VAT that FdlSys mentioned.

PS. This is CoJ

 

Edited April 3, 20197 yr by Zombie