KangaRooted
New Member
@BipedalPrimate, any update on your sparky? Has he come back to you yet?
Grid Tie Victron ESS with DIY LiFePO4 Battery in Australia - Regulatory Issues?
- Thread starter BipedalPrimate
- Start date
On a separate note I spoke with a designer here in Australia and was advised that setting up a Victron ESS system with a Multiplus was achievable here in Australia. They advised having the grid tie inverter at the end of the chain and then the Multiplus with a grid connection. The objective was not to export anything whatsoever, which is fine with me.
The grid tie inverter needs to be able to derate using frequency shifting so that it can dump load. Fronius, SMA and Fimer inverters are capable of doing it. There is also the 1:1 rule which means if you have a 5KW offgrid inverter then you can only have a 5KW max output grid connected inverter. I think this is so the Multiplus is able to shut down the grid inverter completely.
To kick all of this off I will put a 5KW grid tied inverter onto the house and put an offgrid system into my shed. Then once the shed system is running and reliable I will join the two systems together with a cable run. House is still being built so i am in limbo at the moment. My shed system is a baby 12V system running a DC water pump and a fridge only.
The grid tie inverter needs to be able to derate using frequency shifting so that it can dump load. Fronius, SMA and Fimer inverters are capable of doing it. There is also the 1:1 rule which means if you have a 5KW offgrid inverter then you can only have a 5KW max output grid connected inverter. I think this is so the Multiplus is able to shut down the grid inverter completely.
To kick all of this off I will put a 5KW grid tied inverter onto the house and put an offgrid system into my shed. Then once the shed system is running and reliable I will join the two systems together with a cable run. House is still being built so i am in limbo at the moment. My shed system is a baby 12V system running a DC water pump and a fridge only.
BipedalPrimate
New Member
- Joined
- Mar 25, 2022
- Messages
- 61
@KangaRooted Installation is scheduled for 26 June.
KangaRooted
New Member
Unless the plan is to completely turn off the grid connection altogether, I don't understand why you couldn't/shouldn't/wouldn't have the inverter on the incoming line of the Multiplus. Afterall, the rule is that the Multiplus can't backfeed into the grid - not the grid tied inverter. The inverter charges your battery then continues to feed into the grid after the battery is full - (Disclaimer - I've NFI why you'd actually want to do this as the retail provider is stealing that feed in from you at 5c a Kw - but for the sake of the discussion... lets just pretend it might be a good idea
) This would mean you don't need to consider the size of the grid tied inverter as much too.Was there any feedback from the designer on why one option might be okay and not the other? I'm keen to understand the thinking behind it.
Also, what did the designer say about "build your own battery"?
BipedalPrimate
New Member
- Joined
- Mar 25, 2022
- Messages
- 61
I assume you will have the Grid Tie Inverter on the AC Out of the Multiplus.
With Victron ESS & Fronius you do not need to use frequency shifting - see the Fronius Zero Feed-in option in ESS. It uses a direct communication connection between the Cerbo/Venus & Fronius for the Cerbo/Venus to control Fronius PV generation.
The 1:1 rule only applies when the PV inverter is connected to Multiplus AC Out. This is so the max output of the PV inverter does not overwhelm to max output of the Multiplus.
AS @KangaRooted mentioned, there is no limit on the PV inverter size when it is connected to the Multiplus AC In. In this case you do not need to worry about frequency shifting/limiting PV inverter output.
What communication standard would the PV and Multiplus be using to control the PV inverter? if it can't control on the AC out by frequency shifting then that will be a challenge to me as the PV and Multiplus will be ~40m apart in my desired installation.
I would like to have the capability to utilize the Fronius in a grid outage or isolated arrangement. If I end up going to Amber as my provider there are times I wont want to use the grid at all, and other times where I will utilize the grid connection.Unless the plan is to completely turn off the grid connection altogether, I don't understand why you couldn't/shouldn't/wouldn't have the inverter on the incoming line of the Multiplus. Afterall, the rule is that the Multiplus can't backfeed into the grid - not the grid tied inverter. The inverter charges your battery then continues to feed into the grid after the battery is full - (Disclaimer - I've NFI why you'd actually want to do this as the retail provider is stealing that feed in from you at 5c a Kw - but for the sake of the discussion... lets just pretend it might be a good idea
Was there any feedback from the designer on why one option might be okay and not the other? I'm keen to understand the thinking behind it.
Also, what did the designer say about "build your own battery"?
BipedalPrimate
New Member
- Joined
- Mar 25, 2022
- Messages
- 61
It uses Modbus via TCP over ethernet from Cerbo
See 4.3.13. AC-Coupled PV - Zero and Limited Feed-in with Fronius AC PV
So I will have to provide a direct connection between the Fronius and the Cerbo. Might have to pull some Cat6 when I do the cable runs to my shed.
KangaRooted
New Member
Do yourself a favor and pull 2 or 3 runs. You never know when those extra ones may come in handy and you dont wanna have to dig up again if you drop it in a trench....
Good Idea mate I will. Since its going to be CAT6 will pull a few pairs through. It will all be in conduit as well. I also have to pull through a few cables to do what I want to do with the ESS system.
Ghosty
New Member
Hi All,
Sorry for the late late late reply the mate of a mate never turned up, didnt want a bar of it....Good news is there is a post on the vic community forum that says the CEC approval is about 4weeks off. So Mid Sept23 we should be good to go....well in a couple months anyway.
In the mean time consider this....
Dont connect the M2 to the grid at ALL, use your fronus on out1 and use the frequency shift function to throttle down the output of the Fronus (or the modbus over TCIP function).
In the Cerbo Gx, utilize the Generator function through a relay and a contactor, switch on a 20Amp 48v battery charger when the SOC gets to your desired value. Something Like turn on the charger at 17% SOC and turns off again at 25%....Thus no connection between the grid and the M2 / AC side, but still utilizing the grid as a backup energy source. More chargers in parallel the more backup.
The only thing this installation cant do is provide additional AC power to the M2 in times of high load or temp. But having a second M2 to share the load will solve this problem.
This is not advice at all and in no way telling you this is what you are to do!
Sorry for the late late late reply the mate of a mate never turned up, didnt want a bar of it....Good news is there is a post on the vic community forum that says the CEC approval is about 4weeks off. So Mid Sept23 we should be good to go....well in a couple months anyway.
In the mean time consider this....
Dont connect the M2 to the grid at ALL, use your fronus on out1 and use the frequency shift function to throttle down the output of the Fronus (or the modbus over TCIP function).
In the Cerbo Gx, utilize the Generator function through a relay and a contactor, switch on a 20Amp 48v battery charger when the SOC gets to your desired value. Something Like turn on the charger at 17% SOC and turns off again at 25%....Thus no connection between the grid and the M2 / AC side, but still utilizing the grid as a backup energy source. More chargers in parallel the more backup.
The only thing this installation cant do is provide additional AC power to the M2 in times of high load or temp. But having a second M2 to share the load will solve this problem.
This is not advice at all and in no way telling you this is what you are to do!
Last edited:
Ghosty
New Member
Hi BipedalPrimate,
how did the install on the 26th go, did you get across the line ok?
What Batteries did you use?
BipedalPrimate
New Member
- Joined
- Mar 25, 2022
- Messages
- 61
Installed & even have a Certificate of Electrical Safety so it is all legal.
Batteries are on their way from China - EVE LF280K.
KangaRooted
New Member
I'm not sure I understand. What was installed exactly if the battery is still on its way? Can you share some more info about work completed?
BipedalPrimate
New Member
- Joined
- Mar 25, 2022
- Messages
- 61
The intent was to have all the AC wiring done by an electrician and get a COES for that part because the AC is the most dangerous.
So from this:
To this:
The main panel was completely rebuilt & a new sub-panel was installed (see pictures below).
So, until batteries arrive and are installed (by me), the Victron Multi's are operating in pass-thru mode.
Given the delays & problems with getting an electrician to actually do the work, it made more sense (to me at least) to order batteries after successful AC install and COES issued.
Electrician has even offered to come back after battery install to ensure correct labeling and wiring. But because any battery install is Prescribed Electrical Work, a COES can probably not be issued for the battery components.
Including the COES, the work cost AU$3300 which was for 2 electricians for 1.5 days including parts (CB's, Distribution Board, Contactor, Wiring) but excluding Victron equipment & the Grid Protection Relay.
If you are planning a Victron install make sure the electrician verifies cable sizes & wiring with you before and as they install as this one undersized the AC Out 2 cable & CB's because he assumed the label on side of Multi was the current limit - but that value does not take account of any Grid Assist Passthru.
Attachments
Ghosty
New Member
Cheers for the info, Ill try to find a tele NA003.
Champion
Champion
KangaRooted
New Member
Awesome setup!
Thanks very much for sharing.
Do you have to register your battery with the local wholesaler?
If not how come?
One thing I don't understand is the conditions by which you do / or don't need to register. Did the sparky have anything to say about it?
www.energex.com.au
This has led me to believe that if you are connected to the grid, you need to register - but it's a little ambiguous.
I also acknowledge it probably changes from state to state.
Also, can you just throw that changeover switch or is there a period of "no power" in your house when you flick the switch....
Again, thanks for sharing your setup - it looks like a professional job.
Keep the pics coming when you go to do your battery.
Thanks very much for sharing.
Do you have to register your battery with the local wholesaler?
If not how come?
One thing I don't understand is the conditions by which you do / or don't need to register. Did the sparky have anything to say about it?
Battery storage connections - Energex
Before your system is installed, you will need pre-approval from Energex to connect to the grid. Find out how.
This has led me to believe that if you are connected to the grid, you need to register - but it's a little ambiguous.
I also acknowledge it probably changes from state to state.
Also, can you just throw that changeover switch or is there a period of "no power" in your house when you flick the switch....
Again, thanks for sharing your setup - it looks like a professional job.
Keep the pics coming when you go to do your battery.
BipedalPrimate
New Member
- Joined
- Mar 25, 2022
- Messages
- 61
Don't know - there was an initial application for the PV & Fronius which could have included a battery, but didn't. As I am not intending to feed the grid from the battery nor from the Victron's, this design is effectively a battery & inverters plugged into a power point with a Grid Protection Relay to intentionally island.
Not a word & seemed nonplussed by the intended design.
Changeover switch is 3 position so there is a period of no power when using it.
The intended use cases are such that a 10 second period of no power can be managed - there is no life support equipment installed (yet)
.
Snapperhead
New Member
Any update ? How did you go ?
Similar threads
