Afternoon Forum. 

I am looking for some advice regarding putting some panels on my roof. I currently have a 3kW system installed at home. 

My inverter specs are as follows I have a 2.5Kw lithium 24V battery currently. 

Solar Charger Mode:

Rated Current: 50A

System Voltage: 24VDC

SCC VOLTAGE 30V - 72V DC

Operating Voltage Range: 30-32Vdc

Max. Solar Voltage (VOC): 80VDC

 

I am planning on putting 4x 550W panels on the roof and then putting them in parallel. 

What are your thoughts some advice would be greatly appreciated 

1 hour ago, Great Whit3 said:

Afternoon Forum. 

I am looking for some advice regarding putting some panels on my roof. I currently have a 3kW system installed at home. 

My inverter specs are as follows I have a 2.5Kw lithium 24V battery currently. 

Solar Charger Mode:

Rated Current: 50A

System Voltage: 24VDC

SCC VOLTAGE 30V - 72V DC

Operating Voltage Range: 30-32Vdc

Max. Solar Voltage (VOC): 80VDC

 

I am planning on putting 4x 550W panels on the roof and then putting them in parallel. 

What are your thoughts some advice would be greatly appreciated 

Yes you can only put all 4 in parallel due to the 80V limitation. 

52 minutes ago, Scorp007 said:

Yes you can only put all 4 in parallel due to the 80V limitation. 

Do you think 4 of these panels are sufficient for the battery and running in the day ? 

UPS-INV-3KVA-VP-LQ.pdf

5 hours ago, Great Whit3 said:

Do you think 4 of these panels are sufficient for the battery and running in the day ? 

UPS-INV-3KVA-VP-LQ.pdf 1.21 MB · 0 downloads

Your inverter cannot take more than 1200W of solar panels. I just mentioned they must be in parallel as you cannot put the panels in series. Rather look at 3x380W panels. If you want to use 550W you can only use 2.

You will have to provide the load during the day to answer if sufficient. 

Also will you be drawing load from battery during the night? and what load in Watts

Edited January 15, 20233 yr by Scorp007

8 hours ago, Scorp007 said:

Your inverter cannot take more than 1200W of solar panels. I just mentioned they must be in parallel as you cannot put the panels in series. Rather look at 3x380W panels. If you want to use 550W you can only use 2.

You will have to provide the load during the day to answer if sufficient. 

Also will you be drawing load from battery during the night? and what load in Watts

Morning Scorp007. Thanks again for getting back to me. 

I am wanting to go for the larger panel as I will upgrade to a 5kW inverter in time. So the 550W panels are a must for me. I am also tight on roof space I don't have space for many panels on my north facing roof side. 

Load during the day is just home usage at less than 600W in the day at most with the Pcs running and the two fridges. 

Load during the night yes we will be using power but at roughly 1kW between the gaming Pcs and TV's. I will get another battery later this year. 

50 minutes ago, Great Whit3 said:

Morning Scorp007. Thanks again for getting back to me. 

I am wanting to go for the larger panel as I will upgrade to a 5kW inverter in time. So the 550W panels are a must for me. I am also tight on roof space I don't have space for many panels on my north facing roof side. 

Load during the day is just home usage at less than 600W in the day at most with the Pcs running and the two fridges. 

Load during the night yes we will be using power but at roughly 1kW between the gaming Pcs and TV's. I will get another battery later this year. 

So here we go. You will be on the sweet spot if you get 900W from the 2 panels in full sun. You could get 900x5hrs average production per day. This is 4500Wh. Your 8hr day use of 500WX8hrs=4000Wh. Add to it the 600Wh the inverter uses per 24hrs and you are exceeding the production of the panels. No power available after sunset. Also no power to charge the battery. 

Solution. Buy an external MPPT controller and connect panels to it and connect directly to the battery. This will then get some battery charging but no way will you be able to draw 1000W at night.  40A MPPT will get you another 2x550W panels. By now a 5kW inverter with 4-5000W solar input would cost less. 

Sorry but this is what it is. Loads far too high. 

Edited January 16, 20233 yr by Scorp007

4 minutes ago, Scorp007 said:

So here we go. You will be on the sweet spot if you get 900W from the 2 panels in full sun. You could get 900x5hrs average production per day. This is 4500Wh. Your 8hr day use of 500W=4000Wh. Add to it the 600Wh the inverter uses and you are exceeding the production of the panels. No power available after sunset. Also no power to charge the battery. 

Solution. Buy an external MPPT controller and connect panels to it and connect directly to the battery. This will then get some battery charging but no way will you be able to draw 1000W at night. 

Sorry but this is what it is. Loads far too high. 

Absolutely no way of the 1000W in the evening I use worst case for when I get the system up nicely with decent battery capability. Right now evening running is at 380W when in load shedding. 

I am mainly trying to achieve free running in the day Scorp with the two panels. With the 400W actual draw day to day with my lady using her pc for work I think the two panels will do great. 

My final question is the battery is a 2.4kW am I correct in saying that is 2400Wh which then if we look at what we have available 4500wh will charge the battery full then start pushing straight into the house for my Mrs to run free in the day ? 

12 minutes ago, Great Whit3 said:

Absolutely no way of the 1000W in the evening I use worst case for when I get the system up nicely with decent battery capability. Right now evening running is at 380W when in load shedding. 

I am mainly trying to achieve free running in the day Scorp with the two panels. With the 400W actual draw day to day with my lady using her pc for work I think the two panels will do great. 

My final question is the battery is a 2.4kW am I correct in saying that is 2400Wh which then if we look at what we have available 4500wh will charge the battery full then start pushing straight into the house for my Mrs to run free in the day ? 

Yes you can use 0.9x2.4kWh from battery. Bear in mind that is full sunshine day. Some bad rainy days you can get as little as 10% production and quite a bit of 25% production. As you have grid more battery power will help even if charging from the grid. Bad news as you know this is expensive. 

Even 380W for 16hrs when PV production is low/zero needs quite a bit in storage. 6kWh.

Good afternoon.

I am also considering installing 4 x 575 watt jinko panels, with Kodak 3kw inverter/MPPT and 25v Hubble lithium battery.

I'm currently only using 4 units of electricity each day (on average), because I have a gas geyser, and gas hob.

I also have a 24v lead acid inverter connected to the system.

Again, I am told by some installers that the 4 x 575 panels, 3kw inverter, and 25v lithium, should work well. 

Others are saying the 3kw inverter will not cope with the 4 x 575 panels.

Others are saying just go for 475w panels.

Any advice.

My main aim is to keep the fridge going, garage doors working, and some basic appliances, during lengthy power failures.

My existing 24v inverter with lead acid batteries is lasting well during load shedding. only connected to lights and plugs in the lounge and bedrooms.

What do you think?

Alan. Kempton Park

20 hours ago, Alan W said:

Good afternoon.

I am also considering installing 4 x 575 watt jinko panels, with Kodak 3kw inverter/MPPT and 25v Hubble lithium battery.

I'm currently only using 4 units of electricity each day (on average), because I have a gas geyser, and gas hob.

I also have a 24v lead acid inverter connected to the system.

Again, I am told by some installers that the 4 x 575 panels, 3kw inverter, and 25v lithium, should work well. 

Others are saying the 3kw inverter will not cope with the 4 x 575 panels.

Others are saying just go for 475w panels.

Any advice.

My main aim is to keep the fridge going, garage doors working, and some basic appliances, during lengthy power failures.

My existing 24v inverter with lead acid batteries is lasting well during load shedding. only connected to lights and plugs in the lounge and bedrooms.

What do you think?

Alan. Kempton Park

Nothing wrong with the 4 panels. The inverter can accept up to 4kW of panels. 

It will also allow you to expand up to 7 if connected correctly. Theoretical. 

Edited November 24, 20232 yr by Scorp007

On 2023/11/23 at 4:27 PM, Alan W said:

Again, I am told by some installers that the 4 x 575 panels, 3kw inverter, and 25v lithium, should work well. 

Others are saying the 3kw inverter will not cope with the 4 x 575 panels.

You should post a pic of the sticker on the side of the inverter, these 3kW inverters come with varying specs, some only allow 600W of panels, some 1200W, some more, depending on the specific model.

5 hours ago, jumper said:

You should post a pic of the sticker on the side of the inverter, these 3kW inverters come with varying specs, some only allow 600W of panels, some 1200W, some more, depending on the specific model.

Normally stating its a 3kW Kodak is enough info as per my comment as they support 4kW. I have not seen any lower specs for a 3 kW Kodak. 

Yes for most other makes one needs the sticker. 

I find following the specs a better guideline as what somebody said as mentioned by the OP. 

Edited November 26, 20232 yr by Scorp007

17 hours ago, Scorp007 said:

I have not seen any lower specs for a 3 kW Kodak. 

Although not as common, they do exist. Here is one with 1500W mppt: https://solarequipment.co.za/product/kodak-3kw-24v-solar-off-grid-plus-inverter-with-ups/

I only point this out because I have a 3kw axpert (not Kodak brand though) which only takes 600W PV and I've seen Synapse branded models that take 1000W PV... I just like to be absolutely sure as going with incorrect pv specs can be very unforgiving.