Hi Everyone

Am very interested in installing a new solar/battery backup installation at my house.

I have done a lot research on the net, but unfortunately don't have answers I need, and would really appreciate some the forum's members expertise

My current usage ranges from about 400kwh per month in Summer, to 1800 kwh in Winter.

The additional Winter usage is ofcourse due to the usage of heaters.

I'm pretty much looking at covering my full electricity in the warmer months, and then happy to have the excess in winter pulled from the grid.

I currently have a gas stove, and solar geysers that assist in bringing down the current consumption. (I would still like to connect my geyser to the inverter so that the pump works during load shedding and to heat up from battery in the mornings)

My idea would therefore be to have everything run through a hybrid inverter, and where any excess is required from solar/battery this will be pulled from the grid.

I am however on 3 phase electricity though and not sure if this can be rewired to 1 phase?

 

I am planning on installing the following:

• 1 x 8kw Deye/Fusion Hybrid Inverter
• 14 x solar panels
• 2 x 3.5kwh Pylontech batteries.

 

Please let me know your thoughts and if I am on the right track.

 

Thanks

Mark

I've only had my system for just over 2 months, but I will share some of my learnings with you. The more experienced guys will correct me and fill in the gaps where I can't answer.

400kWh to 1800kWh is a big swing, which I assume means you pull a fair bit at once with the heaters.  You will be limited in passthrough amps with the inverter (there is a Sunsynk thread that discussed this recently).  I wouldn't recommend you install these circuits on the essentials side of the inverter, as they will trip your system when the grid does down.  The reason for this is that the batteries can only supply a certain amount at a time. Your proposed batteries will limit you to about (conservatively, call it) 3kW load.  This means that a load exceeding 3kW when the grid fails will trip your system.

 

This will be additionally complicated if your geyser is on essential load side. At a minimum, you would need a geyser timer/management system to balance the peak load.

 

My gut feel here for your proposed kit - you will have to assess your peak loads, possibly needing to reduce them and / or add more batteries.  Your proposed kit will fly in summer, but I have my doubts about winter with your proposed configuration.

7 minutes ago, Craigm said:

I've only had my system for just over 2 months, but I will share some of my learnings with you. The more experienced guys will correct me and fill in the gaps where I can't answer.

400kWh to 1800kWh is a big swing, which I assume means you pull a fair bit at once with the heaters.  You will be limited in passthrough amps with the inverter (there is a Sunsynk thread that discussed this recently).  I wouldn't recommend you install these circuits on the essentials side of the inverter, as they will trip your system when the grid does down.  The reason for this is that the batteries can only supply a certain amount at a time. Your proposed batteries will limit you to about (conservatively, call it) 3kW load.  This means that a load exceeding 3kW when the grid fails will trip your system.

 

This will be additionally complicated if your geyser is on essential load side. At a minimum, you would need a geyser timer/management system to balance the peak load.

 

My gut feel here for your proposed kit - you will have to assess your peak loads, possibly needing to reduce them and / or add more batteries.  Your proposed kit will fly in summer, but I have my doubts about winter with your proposed configuration.

Thanks for the reply @Craigm

yes, My heaters do pull quote a bit in winter. House is pretty cold.

My thinking is I will install the plugs for the heaters on the non-essential side, so if the grid fails then those heathers will be off, which is fine.

Will also have the other high power devices (dishwasher and washing machine) on non essential so I wont run into that problem.

 

Hi Mark

My setup similar (14 x 405 JA Solar mono, 7 east, 7 west), 8kw Inverter and 6.4 Bull)
Your HEATERS is the nasty thing in your setup. (I have taught my wife about socks and jerseys in an attempt to address this)

My geyser, oven (stove top is gas), borehole pump and large air/c is on the non essential load.

In the summer, you will maybe not get through the night with just those 2 batteries (I do have a Zero bill in summer, but then we do have rollback on the meter). In a 2h load shedding, with the night usage as below (15:00 to 23:00), my battery get as low as 75%, so another 2h will take it to 50%. (so it depends have far you want to drain that batteries)

I will empty my pockets, and get another battery, specially if your meter may not / can not be rolled back

PS, The heating function on the air/c use less power (samsung inverter type) than the little bar heater, but wife not like the host air effect.

Edited May 21, 20215 yr by Guss Davey

The downspikes 00:00 to 06:00 is:

• When I walk pass the damm heater, I put it off.
• Next time I walk past it, "a ghost" have switched it on again 🙂
  • some people just like sleeping with the heater on... I will never win.

PS: On the dishwasher.

I have a Smeg and I hardly see a difference when its running. My PC with i9 CPU uses more power.
PS: Only the hotwater line is connected to dishwasher, and my geyser is set to 55.
Normal cycle of dishwasher is 60 and I guess the internal water heater never comes on, because in the beginning of my solar journey I did note down the deltas of power consumption as I used different appliances, and I did not see an effect usually caused by heating elements.

Washing machine and tumble dryers is just as bad as a bar heater. But then again, why complicate it by putting it on non essentials?
JUST impose a "curfew" on the laundry area when the power is off 🙂

We sometimes forget that we having blackouts.... as the only indictor in the house is the clock on the oven which is off during load shedding.
You will also have to teach your fellow house residents some new "skills".

Edited May 21, 20215 yr by Guss Davey

16 hours ago, Guss Davey said:

The downspikes 00:00 to 06:00 is:

• When I walk pass the damm heater, I put it off.
• Next time I walk past it, "a ghost" have switched it on again 🙂
  • some people just like sleeping with the heater on... I will never win.

I understand this. I used to like warmth when I went to bed and warmth when I woke up. The answer was to put the heaters on a timer switch. I would always wake up in a nice warm bedroom but the heater didn't run all night. 

Does "heaters" include electric blankets? 

Moving the plugs used for heaters to non essential loads might be tricky because usually several sockets are on one breaker. Also it is easily defeated.

You've hit on an important point here. To maximise the benefits of any alternate energy system you need to modify your own behavior (or buy a big ass system). 

Get a couple of gas heaters for nights when it's cold and there's no grid. 

We use gas heaters, but switch them off when we go to sleep, precaution against carbon monoxide poisoning 

2 hours ago, Tariq said:

We use gas heaters, but switch them off when we go to sleep, precaution against carbon monoxide poisoning 

Samsung had a 30% special on inverter aircons. They are very efficient. I put mine on max heat until you feel nice and toasty then turn it down to 26 degrees. Also don't forget to weather strip all your doors and windows. 

Gas heater FTW.

Thanks all the response. 

Had the installer here on Friday to have a look. 

He reckons I could get away with 12 panels. 

My roof however faces north east. Will this be a problem? 

I would assume it would just mean that the panels aren't quite as efficient and will also start producing power a little earlier In the morning? 

Installer reckons to only have the dishwasher /washing machine on non essential. Says doesn't make sense to rewire the plugs just for the heaters. 

Also, what he says which I don't understand is that if I have say A 5kw inverter, then the max power I can use at a time is 5kw. My understand is that while the grid is up, it would just pull the additional from the grid without tripping the system. This is my understanding from some of the other threads on the forum, so now really confused. 

 

@Mark M Some solar panel technology is more sensitive than others regarding its orientation to the sun.

Speak to your solar guy about that.

I use JA Solar mono crystal half cell panels on a east and west at 15 degree pitch, and the efficiency is great (summer).
I have no reference to compare it with for the winter angle of the sun, but I guess efficiency related to pitch and direction has a greater impact during winter than in the summer.

On 2021/05/23 at 3:48 PM, Mark M said:

Also, what he says which I don't understand is that if I have say A 5kw inverter, then the max power I can use at a time is 5kw. My understand is that while the grid is up, it would just pull the additional from the grid without tripping the system. This is my understanding from some of the other threads on the forum, so now really confused. 

 

This is incorrect and he will not be the first installer that doesn't know the full potential of a proper hybrid inverter. 

The 5kw sunsynk/deye inverters can have up to 35A on the inverter of the grid is available. Meaning you can run 7.7kw on the 5kw inverter (35A*220V).

Been there, done that, had 7.65 kW total load ( essential and non essential) on a 5 kW Sunsynk for over an hour

Thanks all for your responses, been a great help.

Now, 1 last question before I sign the quote and go ahead.

 

Deye or SunSynk.

Installer says better support with Deye, but from reading this forum, I tend to think think SunSynk is the better option?

 

 

There are a lot more of us Sunsynk owners on this forum, the interface is a lot better and support is provided by the same people in South Africa

58 minutes ago, Mark M said:

Thanks all for your responses, been a great help.

Now, 1 last question before I sign the quote and go ahead.

 

Deye or SunSynk.

Installer says better support with Deye, but from reading this forum, I tend to think think SunSynk is the better option?

 

 

Hi Mark. Go for the Sunsynk. Better after sales support. 

2 hours ago, Mark M said:

Thanks all for your responses, been a great help.

Now, 1 last question before I sign the quote and go ahead.

 

Deye or SunSynk.

Installer says better support with Deye, but from reading this forum, I tend to think think SunSynk is the better option?

 

 

Sunsynk for sure. The UI is great,

And Sunsynk sounds cool, it's a proper noun, cannot be confused with a similar sounding adjective 😉 Not sure what the Die marketing people were thinking at the time.  

Sorry, have one last question..

I've just been told that the below pv panel's current is too high for the 5kw inverter:

I know the max input current is 11A per MPPT. 

Do look at Isc or Imp? 

Tiger 460W Mono-Facial 

• Electrical Data | STC*
• Nominal Max. Power (Pmax): 460W
• Opt. Operating Voltage (Vmp): 43.08V
• Opt. Operating Current (Imp): 10.68A
• Open Circuit Voltage (Voc): 51.70V
• Short Circuit Current (Isc): 11.50A
• Module Efficiency up to: 20.49%

 

System has been ordered...So excited!!

 

• 12 x Jinko 460W panels
• Sunsynk 8kw Inverter
• 2 x Pylontech 3000C Batteries

 

Thanks all for your help,  not sure what I would have done without this forum!

On 2021/05/23 at 3:48 PM, Mark M said:

Thanks all the response. 

Had the installer here on Friday to have a look. 

He reckons I could get away with 12 panels. 

My roof however faces north east. Will this be a problem? 

I would assume it would just mean that the panels aren't quite as efficient and will also start producing power a little earlier In the morning? 

Installer reckons to only have the dishwasher /washing machine on non essential. Says doesn't make sense to rewire the plugs just for the heaters. 

Also, what he says which I don't understand is that if I have say A 5kw inverter, then the max power I can use at a time is 5kw. My understand is that while the grid is up, it would just pull the additional from the grid without tripping the system. This is my understanding from some of the other threads on the forum, so now really confused. 

 

My roof also faces NE. Not a complete trainsmash. I lose maybe 3 hours in winter of the sun. In summer, my PV starts to generate nice wattage around 7am and whittles down around 17h30 or 18h00. In winter the PV starts pushing wattage nicely around 8am and whittles down around 16h00. For what its worth. 

@Vassen, according to the Chinese help desk, 5 kW inverter is 13 amps on the mppt

And I am stuck with 355 watt panels and hardly any additional roof space 😖

18 hours ago, Tariq said:

according to the Chinese help desk, 5 kW inverter is 13 amps on the mppt

I learned about this just in time to still be able to change my order for additional panels - and hence could opt for the larger ones

Just out of interest.

What was the cost of installation.

Minus inverter, panels, batteries?

Wires, addition dB boards, brackets, labour,etc