Jump to content

Mr


Eddie Louw
 Share

Recommended Posts

I have a 5kw pure sine  wave Kodak hybrid converter, a 3.5 Kwh lithium Ion battery and 8 340W JA solar panels installed. Why is it that the Watage delivered by the panels is constantly lower than the Watage of the load, no matter whether the load is low  or high. I am therefor constantly use some utility power no matter whether I have full so shine or not. When the load is very high the Watage from the panels also jumps up high, but always stays lower than the load. Is this normal or could there be something wrong with the settings? The settings are all on default where applicable. 

Eddie Louw 

Link to comment
Share on other sites

On the Sunsynk there is an option that specifies zero export power. What this option actually does is set a specific amount of power it must always pull from the utility in order to prevent accidental feeding back into the utility as this will trip some prepaid meters. And for other it might just mean you get billed for the bit of power you feed back accidentally.

So if I set this value to say 100W and I have a 1000W load, I might see just over 900W from the solar and 100W from Eskom to cover the load. Perhaps this is what you're experiencing?

Link to comment
Share on other sites

14 hours ago, Eddie Louw said:

I have a 5kw pure sine  wave Kodak hybrid converter, a 3.5 Kwh lithium Ion battery and 8 340W JA solar panels installed. Why is it that the Watage delivered by the panels is constantly lower than the Watage of the load, no matter whether the load is low  or high. I am therefor constantly use some utility power no matter whether I have full so shine or not. When the load is very high the Watage from the panels also jumps up high, but always stays lower than the load. Is this normal or could there be something wrong with the settings? The settings are all on default where applicable. 

Eddie Louw 

What's the SOC of the battery when you see this behaviour? If SOC is 100% and you're not exporting then solar will track load.

Link to comment
Share on other sites

3 hours ago, Paul Greeff said:

On the Sunsynk there is an option that specifies zero export power. What this option actually does is set a specific amount of power it must always pull from the utility in order to prevent accidental feeding back into the utility as this will trip some prepaid meters. And for other it might just mean you get billed for the bit of power you feed back accidentally.

So if I set this value to say 100W and I have a 1000W load, I might see just over 900W from the solar and 100W from Eskom to cover the load. Perhaps this is what you're experiencing?

I have a prepaid meter and as far as I know my system cannot feed back into utility, and my inverter does not have such a setting. 

Link to comment
Share on other sites

No you don't want utility charging at all. Charge from solar only. You will generate the maximum possible until you reach 100% SOC, then load follow. Then stay on the battery at night and only go to grid at a low SOC- low enough to extract maximum benefit from the batteries, high enough to deal with possible load shedding in the early hours. Then in the morning you've got lots of headroom in the battery to generate maximum again.

Watch out for being under batteried. Your inverter can draw more than the recommended battery load which could shorten its life. I have 2 x 3.5kwh on a 5kva and it gets me through the night if I get it to 100% SOC before sunset, and I don't exceed max amps

 

Edited by Hagu13
Link to comment
Share on other sites

I myself is not too knowledgeable on a solar system and mostly rely on the installers, which was Markpole Electrical. 

My main concern was that should my battery not be full when load shedding starts, I could run into trouble. That could happen should too much battery power was used during the day and not enough sunshine to replenish before nightfall. 

Two questions in this regard. 1. I conclude from your notes there is a difference in battery life if the battery power is used frequently as to being kept full? 2. Does "load" include both charging the battery and the power used by the householding? That was my assumption when putting the settings on load first and that utility would only be used when PV is not enough to service both. 

Link to comment
Share on other sites

Lithium batteries don't mind cycling so you should allow this to extract the maximum savings. Any time your battery is full is wasted sun on your panels. Suggest you figure out your night time load profile- this is quite easy if you have monitoring software, otherwise just time it. If your battery takes say 4 hours to drop from 100% to 20% after dark on a typical night, then you can set it to go to grid at 60% SOC if you are expecting 2 hours of load shedding, and 20% if you're not expecting it. Then it will drop from 60 to 20 during load shedding.

I have the whole house on my system. 5 people, 5 TV's, 2 fridges, tons of smart devices. But all our lighting is LED which uses next to nothing. We pull about 250W (including the 50W or so the inverter uses) overnight (the outside lighting is on 24/7) and my battery bank drops about 10% per hour. We're on battery till at least 4am every night and through the night sometimes. I have fewer panels than you so don't get to 100% SOC always. If load shedding is expected between 4am and 8am I change the changeover to 40% SOC to save the last usable 20% for that. 

I'm not familiar with your inverter so can't comment on what you're seeing

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...