Need Advice re Solar System

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deonengelbrecht

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I have two connected Luxpower SNA5000 inverters and a 5kw battery. Solar panels 4500w. The system runs entirely on the panels and batteries with the grid only as backup. Even when running off solar & batteries that they still draw current from the grid. It was installed only a few days ago. I noticed a usage of 8kw from the grid today. Any comments please !!( please keep in mind I'm a non-technical person).
 
deonengelbrecht said:
I have two connected Luxpower SNA5000 inverters and a 5kw battery. Solar panels 4500w. The system runs entirely on the panels and batteries with the grid only as backup. Even when running off solar & batteries that they still draw current from the grid. It was installed only a few days ago. I noticed a usage of 8kw from the grid today. Any comments please !!( please keep in mind I'm a non-technical person).
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A usage of 8kW or 8kWh?
 
TheChamp said:
He probably meant most of the time, since he did not utter the dreaded, "I am off grid" phrase.
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I'm not off grid. I do have a farmhouse where I have an off grid system. In the case I'm asking about, the settings was only finalized yesterday. It's easy to keep an eye on it with the app. In the 30 hours, it didn't take energy from the grid. I have little technical knowledge. I guess my question refers to how much energy does 'the system' needs to operate
 
deonengelbrecht said:
I'm not off grid. I do have a farmhouse where I have an off grid system. In the case I'm asking about, the settings was only finalized yesterday. It's easy to keep an eye on it with the app. In the 30 hours, it didn't take energy from the grid. I have little technical knowledge. I guess my question refers to how much energy does 'the system' needs to operate
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You can post a Pic of the usage you saw if you have it in the app.

On they system usage, it depends but around 50W and not more than 100W.
 
Tomtomtom said:
Which is, 1.2 to 2.4 kWh per day, or 1.2 to 2.4 units. For OP clarity
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Although we still don't if it's instantaneous power draw of 8kW he saw or a energy usage in kWh. I just read the OP again and see there are two inverters connected.
 
deonengelbrecht said:
I have two connected Luxpower SNA5000 inverters and a 5kw battery. Solar panels 4500w. The system runs entirely on the panels and batteries with the grid only as backup. Even when running off solar & batteries that they still draw current from the grid. It was installed only a few days ago. I noticed a usage of 8kw from the grid today. Any comments please !!( please keep in mind I'm a non-technical person).
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Most likely the battey does not last the night and starts using grid at times

Or is incapable to handle the load during peak

The invertes is likely set to not exceed the battery max then assists from grid
 
Is it advisable to get a 2nd hand system?

My folks along the coast want to go solar - current options are 6KW system with 4 panels for R57k but installer is upgrading another client and has 3KW system he says they will sell for considerably less (don't have price yet) (warranty balance on the battery and the panels, his inverter is just out if warranty but has been serviced and fans replaced)
 
Hemps said:
My folks along the coast want to go solar - current options are 6KW system with 4 panels for R57k but installer is upgrading another client and has 3KW system he says they will sell for considerably less (don't have price yet) (warranty balance on the battery and the panels, his inverter is just out if warranty but has been serviced and fans replaced)
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Yes why not, if the installer is 100% reputable, and there's a service history (like for a car...)

Bigger question is why 3 kW is even an option given they were looking at 6 kW? Those are very different systems. Maybe 1 or 2 kW is also fine?
 
Tomtomtom said:
Yes why not, if the installer is 100% reputable, and there's a service history (like for a car...)

Bigger question is why 3 kW is even an option given they were looking at 6 kW? Those are very different systems. Maybe 1 or 2 kW is also fine?
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They retired and only 2 of them, all they need to run is fridge, freezer, geyser, TV + dstv decoder when the power fails, like today again cables thieves so no power until tomorrow.
 
Hemps said:
They retired and only 2 of them, all they need to run is fridge, freezer, geyser, TV + dstv decoder when the power fails, like today again cables thieves so no power until tomorrow.
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In that case I wouldn't spend more than about R 20k since 1-2 kW / 1-2 kWh is plenty for the electronics and can run the fridge if need be. If he's offering the 3 kW (assuming 3 kWh battery?) for about that price then I'd go for it.

The geyser is not feasible to run off an inverter less than 5 kW but it's wasteful going there just for that since geysers don't need AC. Can get a Geyserwise PV system or similar with 2 dedicated panels at a cost about R 12k - and will pay back in 3-4 years in electricity savings.
 
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Hemps said:
Is it advisable to get a 2nd hand system?

My folks along the coast want to go solar - current options are 6KW system with 4 panels for R57k but installer is upgrading another client and has 3KW system he says they will sell for considerably less (don't have price yet) (warranty balance on the battery and the panels, his inverter is just out if warranty but has been serviced and fans replaced)
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Remaining battery lifespan and cycle count? Those 10 year battery life span is calculated by fully charge/discharging battery every day for 10 years giving you 3650 plus cycles.
 
rh1 said:
Remaining battery lifespan and cycle count? Those 10 year battery life span is calculated by fully charge/discharging battery every day for 10 years giving you 3650 plus cycles.
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Thanks, will have to ask, its still early days but have asked them to do a site visit first.
 
Hemps said:
They retired and only 2 of them, all they need to run is fridge, freezer, geyser, TV + dstv decoder when the power fails, like today again cables thieves so no power until tomorrow.
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Geyser, should not be on such a small system, modern geysers by law can only lose a certain amount of heat over 24 hours, so it is generally okay for a hot shower the next day. If I am last to shower, I just dont use cold water at all. Get a wifi smart timer, and switch geyser on from a phone, after load shedding to heat the water.
 
as long as you are happy with the limitation on pv capacity on a 3kw

the other problems is saving eskom power on a axpert type is more work , and homework
if backup power is the main focus not as big a deal

the only things new in my setup is the panels the inverter and batteries was 2nd hand / 2nd life cells
just bought more 2nd hand stuf to expand, gotta make sure the stuff is working right though

so buying from an installer upgrading a system and can confirm all works fine probably best
older people tend to struggle to get to grips on how they work, not all old people are as sharp as Berny Sanders

for the small price of a raspberry pi 2w and Solar assistant you could manage remotely if they struggle especially if you don't stay close, does also help with savings as you can set automations to switch to SBU during the day and back to eskom at night
 
Much cheaper to add a small gas geyser to one of the showers in the house and do the solar for fridges, TV, internet and lights only. Throw in a gas 2 plate stove and you can go about your life normally for the most part.
 
So because we cant mount batteries on wall, prefab mostly they'll have to be on the ground.
3.2KW + 2.5kwh battery + 4 panels = R54k
5KW + 5kwh battery + 4 panels = R65k

Essentially a retirement home so small but they do have days were there is no eskom power but sunlight is very good.
 
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