System Upgrade path

Mzezman

Mzezman

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Also posted on Powerforum but keen to get your input:

Have had my current system for about 2 months now - has worked flawlessly - current specs:
  • 1 x Sunsynk 5kw Inverter
  • 1 x Dyness 4.8 kWh battery
  • 8 x 335W CNBM panels on MPPT1 facing north
The plan was always to upgrade at some point and i have started looking at the upgrade path. Asked for a quote from my installer who suggested:
  • Additional battery
  • 10x 335W CNBM panels. 1 to join MPPT1 and the other 9 on MPPT2
Would you go for the 335s (R2100 / panel) OR go for fewer higher wattage panels (455 / 540s)? Roof space is not such a huge consideration and if needed i could split MPPT2 to have some panels on North and other on North West roofs

They are also charging me 13.8k for this installation which i think is high. Any thoughts / comments / alterations?
 
Similar type of question: How would you split 14 panels between East and West Facing roofs?
 
Mzezman said:
Also posted on Powerforum but keen to get your input:

Have had my current system for about 2 months now - has worked flawlessly - current specs:
  • 1 x Sunsynk 5kw Inverter
  • 1 x Dyness 4.8 kWh battery
  • 8 x 335W CNBM panels on MPPT1 facing north
The plan was always to upgrade at some point and i have started looking at the upgrade path. Asked for a quote from my installer who suggested:
  • Additional battery
  • 10x 335W CNBM panels. 1 to join MPPT1 and the other 9 on MPPT2
Would you go for the 335s (R2100 / panel) OR go for fewer higher wattage panels (455 / 540s)? Roof space is not such a huge consideration and if needed i could split MPPT2 to have some panels on North and other on North West roofs

They are also charging me 13.8k for this installation which i think is high. Any thoughts / comments / alterations?
Click to expand...
I would go with 8 x 455W on its own string. Much more bang for your buck.

Btw. My install for 6 x 455W panels is R3000.
 
ADrunkTeddyBear said:
I would go with 8 x 455W on its own string. Much more bang for your buck.

Btw. My install for 6 x 455W panels is R3000.
Click to expand...
That's a good price for install - im assuming that's the brackets, cables and wiring?
 
ADrunkTeddyBear said:
I would go with 8 x 455W on its own string. Much more bang for your buck.

Btw. My install for 6 x 455W panels is R3000.
Click to expand...
Surely thats not the industry norm? No professional installer could charge that and survive?
 
Mzezman said:
Managed to get the extra panels and have the battery enroute

Panels got installed today so total of 18x335w

View attachment 1257408View attachment 1257410
Click to expand...
I'll start off with 8 x 545w panels only. 4Kw.

Is the 18 x 335 = 6Kw enough? I know its enough for average household but I want to be able to run everything.

Will aim for 12Kw. 8 panels now and then phase 2 another 8 and in phase 3 another 8.

Batteries will be main issue. Enough to run house during the night. Currently have only 2 x 3.5kw Pylontechs. Will probably need 4 to 6 to run house overnight?
 
Saba'a said:
I'll start off with 8 x 545w panels only. 4Kw.

Is the 18 x 335 = 6Kw enough? I know its enough for average household but I want to be able to run everything.

Will aim for 12Kw. 8 panels now and then phase 2 another 8 and in phase 3 another 8.

Batteries will be main issue. Enough to run house during the night. Currently have only 2 x 3.5kw Pylontechs. Will probably need 4 to 6 to run house overnight?
Click to expand...
For phase 2 maybe look at 4 panels + an extra battery. Then for phase 3 another 4 panels + battery. This should give you 8kWp PV + 14kWh storage.

This should honestly be enough to charge your batteries well before midday and then run your house.

On 6.3kWp I struggle to hit more than 4kW and that's when the batteries are charging. Putting your geyser etc on essential will push it up but 8kWp should be more than enough.

The issue as you say is battery capacity, so focus on that...
 
Mzezman said:
Managed to get the extra panels and have the battery enroute

Panels got installed today so total of 18x335w

View attachment 1257408View attachment 1257410
Click to expand...
Keen to hear how long your battery bank lasts. We both have the same batteries at 9.6kWh and I get to around 1am before switching to grid. The 15 outside lights doesn't help even though they're 9w LEDs, but it's needed for security on a large-ish plot.

With 80% DOD I have them set to switch over at 45% SOC - 15% for 2 hour load shedding + 10% buffer in case it goes over. Leaving 20% per the DOD...
 
Mike Hoxbig said:
For phase 2 maybe look at 4 panels + an extra battery. Then for phase 3 another 4 panels + battery. This should give you 8kWp PV + 14kWh storage.

This should honestly be enough to charge your batteries well before midday and then run your house.

On 6.3kWp I struggle to hit more than 4kW and that's when the batteries are charging. Putting your geyser etc on essential will push it up but 8kWp should be more than enough.

The issue as you say is battery capacity, so focus on that...
Click to expand...
Thanks

Have 3 x geysers plus aircon, thus wanting to push panels higher.

But hear you. If batteries charged and enough, then size of panels not that big an issue.

Good idea ito 4 panels + battery per phase.
 
Mike Hoxbig said:
Keen to hear how long your battery bank lasts. We both have the same batteries at 9.6kWh and I get to around 1am before switching to grid. The 15 outside lights doesn't help even though they're 9w LEDs, but it's needed for security on a large-ish plot.

With 80% DOD I have them set to switch over at 45% SOC - 15% for 2 hour load shedding + 10% buffer in case it goes over. Leaving 20% per the DOD...
Click to expand...
I'm also keen to see how far we get - I, like you have some outside lights drawing approx 200w from 7pm to 5am so thats where most of my night time consumption goes. Geysers are still off 'essentials' but when the battery is installed will get the CT coil fixed. My evening base load is approx 400W (the balance is the network kit, IP cameras, alarm and fridge)

Also been debating whether to use the battery from 6pm onwards OR from 10pm onwards... will run a few tests but the 6-8pm slot is heavy in my household
 
Saba'a said:
I'll start off with 8 x 545w panels only. 4Kw.

Is the 18 x 335 = 6Kw enough? I know its enough for average household but I want to be able to run everything.

Will aim for 12Kw. 8 panels now and then phase 2 another 8 and in phase 3 another 8.

Batteries will be main issue. Enough to run house during the night. Currently have only 2 x 3.5kw Pylontechs. Will probably need 4 to 6 to run house overnight?
Click to expand...
So its more than enough for me - for now! On the phase 1 kit (2.4kwp) i used to run the whole home during sunny days with no issues. So that was all the WFH kit for wife and I, pool pump from 10am to 2pm, washing machine, dishwasher, CCTV, alarm and even 1 aircon on low to mid settings. I DID struggle on overcast / rainy days though hence the upgrade to 6kWp and additional battery.

During / after winter i MAY increase battery bank by 1 more but i am maxed out on PV on the 5kw... i would need either another one or upgrade to an 8kw. But for now this works for me. Will see how it handles having the geysers on PV though
 
Mike Hoxbig said:
Keen to hear how long your battery bank lasts. We both have the same batteries at 9.6kWh and I get to around 1am before switching to grid. The 15 outside lights doesn't help even though they're 9w LEDs, but it's needed for security on a large-ish plot.

With 80% DOD I have them set to switch over at 45% SOC - 15% for 2 hour load shedding + 10% buffer in case it goes over. Leaving 20% per the DOD...
Click to expand...
Whats your base load from say 10pm to 6am?
 
Mzezman said:
Whats your base load from say 10pm to 6am?
Click to expand...
From 6pm - 1am it's about 700w. Then it drops to around 400w from 1am after I switch the TV and lounge lights off and go to bed.

The 400w from 1am to sunrise is because of the 15 x 9w LEDs, 2 fridges, a chest freezer and the bathroom light which I leave on so it's not too dark for the kids room.

At 700w, it's about 7.5% discharge per hour. Another battery should take me through to sunrise at my current settings. Currently purchasing about 3.5 units a day excluding geyser...
 
Mike Hoxbig said:
From 6pm - 1am it's about 700w. Then it drops to around 400w from 1am after I switch the TV and lounge lights off and go to bed.

The 400w from 1am to sunrise is because of the 15 x 9w LEDs, 2 fridges, a chest freezer and the bathroom light which I leave on so it's not too dark for the kids room.

At 700w, it's about 7.5% discharge per hour. Another battery should take me through to sunrise at my current settings. Currently purchasing about 3.5 units a day excluding geyser...
Click to expand...
I think we can definitely compare almost like for like then - will let you know once i have the 2nd battery (Thursday) then we can start the monitoring. I was also saying to the wife that a 3rd battery would definitely see us not using eskom unless absolutely needed (to which i got raised eyebrows). I am currently purchasing between 5 and 15 units depending on whether the aircons are used after 4pm but my aim is to get that to less that 10 units/day
 
Eish my usage is about 600w (excl 3 geysers), midnight to morning.

2 deep freezers
2 fridges
Cameras
Alarm
Lights, some motion detection
Lots of IoT switches

Not sure why mine more.
 
Saba'a said:
Eish my usage is about 600w (excl 3 geysers), midnight to morning.

2 deep freezers
2 fridges
Cameras
Alarm
Lights, some motion detection
Lots of IoT switches

Not sure why mine more.
Click to expand...
It all adds up... the 2 deep freezers + fridges will easily pull 300w if they are older models... then lights another 100w...
 
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