Planning a solar system

Also my 2 cents. Spend money on a decent invertor. Most of the cheap ones have crap efficiency and may look good on paper but in practice are bleh. Also if you can get a bigger single one than 2 in parrallel I would do that as well.
 
Gary Waterworth said:
Also my 2 cents. Spend money on a decent invertor. Most of the cheap ones have crap efficiency and may look good on paper but in practice are bleh. Also if you can get a bigger single one than 2 in parrallel I would do that as well.
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The question of expensive always being better? I am still undecided on that, sometimes expensive just talks to the popularity of the brand and nothing else.

Of course, I won't stand in the way of facts if they are presented to me.
 
JayN said:
Hi Crusader ... I have a domestic 3 phase supply and went with a Sunsynk 12kw 3 Phase inverter in Sept 2021.
My usage is around 30kwh per day. I have a peak in the morning between 4 and 7 when the two geysers come on.

I have 4.3kw (name plate capacity) of panels, which on an average sunny day gives me about 20 kwh per day, and a cloudy day about 12kwh. A really rainy day gives me 5-6kwh.

I have one 5.5kwh battery (Hubble AM2) which cushions the production and load during the day. I dump excess power to to the geyers during the day and so the water is hot for the early evening showers.

Because I have only one battery, I save the battery at 90% charge until midnight in case of a power failure. After midnight it slowly drains to 25% until around 5am. Then the sun comes up and by around 9.00 am I am producing 2.5kw.

The inverter comfortably handles the load and is more than sized for my needs.

I could do with another 4.3kw of panels and another 1 battery in the short term (3 total in long term). This will more or less free me from the grid for 85% of the year (not totally on cloudy days). I am based in JHB.
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How do you manage excess to geysers.

The inverter manages it? Home Assistant? Manually?
 
TheChamp said:
The question of expensive always being better? I am still undecided on that, sometimes expensive just talks to the popularity of the brand and nothing else.

Of course, I won't stand in the way of facts if they are presented to me.
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I had 2 x 5K of the voltronic based invertors. Cant remember the brand , but they are all similar. Lasted a year. Counted it as school fees and went and got a 8kw Sunsynk. Chalk and Cheese.....
 
Gary Waterworth said:
I had 2 x 5K of the voltronic based invertors. Cant remember the brand , but they are all similar. Lasted a year. Counted it as school fees and went and got a 8kw Sunsynk. Chalk and Cheese.....
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How about an 8kW Victron for R57k? And an MPPT for R16k? There will always be something more expensive, question is, should you always go for that because expensive is better? Or do you go for what suit your needs?

The guy I was helping with the Pylontech battery is still running his Axpert King after years of installation, yours must have been something extremely nasty to only last for one year.
 
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Yup, it isnt allways about price. Agreed on that. I did look at the Victron, but the modular approach puts me off. Personal preference I know.

It was one of the axpert clones, Kodak. From an efficiency pov Sunsynk leaves them behind.
 
furpile said:
Is this the correct Efergy to get? We are moving soon and I want to start measuring as soon as possible. I see stock is only due in May though. Anywhere else with stock or another product to use?

EFERGY Standalone Home Hub Kit - Electricity Energy Power Wattage Monitor Watt Meter​


Gadgets

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This is the kit I got - https://www.geewiz.co.za/smart-home...-energy-power-wattage-monitor-watt-meter.html

You don't have a web interface for stats etc. The usage is shown directly on the screen. You can export data by plugging in a USB drive and then opening a spreadsheet to create your own stats.
 
Saba'a said:
How do you manage excess to geysers.

The inverter manages it? Home Assistant? Manually?
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I have two CBI astutes installed which I can set easily on my phone. Through trial and error I've found the right amount time to leave the geysers on until hot and when they need to come on and go off. I seldom go in to change the setting. If we have a random power failure during the day, I can switch off the geysers. I could link it to the invert via home assistant of IFTTT but I don't see the need at this point. The geysers have to come on before we get home, so they either use the excess solar or the grid. I'm not phased as grid use is minimal and I barely go above 450 kW per month. Each kW up to 600 is only R2.00 per kWh.
 
JayN said:
I have two CBI astutes installed which I can set easily on my phone. Through trial and error I've found the right amount time to leave the geysers on until hot and when they need to come on and go off. I seldom go in to change the setting. If we have a random power failure during the day, I can switch off the geysers. I could link it to the invert via home assistant of IFTTT but I don't see the need at this point. The geysers have to come on before we get home, so they either use the excess solar or the grid. I'm not phased as grid use is minimal and I barely go above 450 kW per month. Each kW up to 600 is only R2.00 per kWh.
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Cool I have CBI ASCs on each geyser. Currently on time schedule during day and night.

Guess must just figure out time it takes to heat. But would be useful to know temp of geysers to finetune things.

But will only have 8 x 545w pvs so max 4kw really only. But I'll see how it goes.
 
Saba'a said:
Cool I have CBI ASCs on each geyser. Currently on time schedule during day and night.

Guess must just figure out time it takes to heat. But would be useful to know temp of geysers to finetune things.

But will only have 8 x 545w pvs so max 4kw really only. But I'll see how it goes.
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Hi Saba'a,

I also have 8 x 540w panels.

The sun strikes my panels at around 9.30 am, and that is when my solar gen exceeds my household demand. With the pool pump on at 08.45 (750w), my battery starts to charge at 09.40 from 25% and under a normal day with average clouds gets to 100% by around 12.00.

I bring the Geyser 1 on at 11.30 to 12.40. It is a 3kw geyser (probably set at 60 degrees) and it takes about 1.10 mins to heat from semi warm after two people have had a shower from a hot geyser.

I leave the system to recover a bit and bring Geyser 2 on at 13.45 to 14.40. It is a 4kw geyser (also probably set at 60 degrees) and it takes about 40 mins to get hot from semi warm after one person has had a shower from a hot geyser. I leave it on a bit extra because the thermostat cuts off the electricity and just in case it was a bit colder when it started off.

I have a 5kw battery to buffer, and it charges/discharges at 1C.

By 16.30, my battery is back at 90% or even 100% if there are no afternoon clouds.

Pool pump goes off at 16.45.

These timings work well with my system. Both geyser are hot by the time we reach home and shower at around 18.00.

I heat the geysers up again for similar timing starting at 04.00 in sequence (not together) for the morning showers. This usage is usually mostly on grid.
 
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Saba'a said:
Cool I have CBI ASCs on each geyser. Currently on time schedule during day and night.

Guess must just figure out time it takes to heat. But would be useful to know temp of geysers to finetune things.

But will only have 8 x 545w pvs so max 4kw really only. But I'll see how it goes.
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On the CBI astutes you can see when the thermostat cuts out the power on the "electric" tab. That way you will know how long it takes to heat up. Time it once and there you have the settings.
 
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JayN said:
On the CBI astutes you can see when the thermostat cuts out the power on the "electric" tab. That way you will know how long it takes to heat up. Time it once and there you have the settings.
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You using cbi app I assume as I dont see this in Smart Life app?
 
JayN said:
On the CBI astutes you can see when the thermostat cuts out the power on the "electric" tab. That way you will know how long it takes to heat up. Time it once and there you have the settings.
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You will also need to adjust for the season: in Gauteng winter I need to extend times by as much as 25%
 
rrh said:
You will also need to adjust for the season: in Gauteng winter I need to extend times by as much as 25%
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Thanks ... I know this is coming. 25% more heating is about right, but also depends on insulation. I don't have any exposed pipes (hot or cold) so I am hoping it would be a closer to 10% extra.
 
JayN said:
Thanks ... I know this is coming. 25% more heating is about right, but also depends on insulation. I don't have any exposed pipes (hot or cold) so I am hoping it would be a closer to 10% extra.
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My pipes are also all insulated so normally it is not as much as 25%:

I generally allow 15%, (mid-summer to mid-winter) mainly 'cos I have no particular wish to finish in a lukewarm shower :)
 
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