System Upgrade path

[Mzezman]

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?

 

[Academic]

Similar type of question: How would you split 14 panels between East and West Facing roofs?

 

[semaphore]

Similar type of question: How would you split 14 panels between East and West Facing roofs?

Evenly.

 

[Mzezman]

Similar type of question: How would you split 14 panels between East and West Facing roofs?

Yeah - as @semaphore mentioned, 7 per side and each side on an MPPT

 

[ADrunkTeddyBear]

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?

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.

 

[Mzezman]

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.

That's a good price for install - im assuming that's the brackets, cables and wiring?

 

[ADrunkTeddyBear]

That's a good price for install - im assuming that's the brackets, cables and wiring?

I bought the panels, cables and brackets myself. He is just coming to wire everything up

 

[Mzezman]

Managed to get the extra panels and have the battery enroute

Panels got installed today so total of 18x335w

 

[Saba'a]

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.

Surely thats not the industry norm? No professional installer could charge that and survive?

 

[Saba'a]

Managed to get the extra panels and have the battery enroute

Panels got installed today so total of 18x335w

View attachment 1257408 View attachment 1257410

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?

 

[Mike Hoxbig]

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?

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...

 

[Mike Hoxbig]

Managed to get the extra panels and have the battery enroute

Panels got installed today so total of 18x335w

View attachment 1257408 View attachment 1257410

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...

 

[Saba'a]

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...

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.

 

[Mzezman]

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...

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

 

[Mzezman]

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?

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

 

[Mzezman]

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...

Whats your base load from say 10pm to 6am?

 

[Mike Hoxbig]

Whats your base load from say 10pm to 6am?

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...

 

[Mzezman]

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...

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

 

[Saba'a]

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.

 

[Mzezman]

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.

It all adds up... the 2 deep freezers + fridges will easily pull 300w if they are older models... then lights another 100w...