From the circuit breaker panel there are multiple power distributions to non critical systems in the house (water heaters/washing machine/etc). And one to the Muliplus.
If I would setup an ESS I’ve been reading that small amounts of feeding into the grid could happen. I have no problem with that and my grid supplier doesn’t care too much as long as it’s minor.
But with my wiring order it seems that the power is feedback into my home system first before it goes to the grid. Does it work like that? Or is the Multiplus required to be the first unit after the grid meter before my house circuit breaker panel?
I have, multiple diagrams even. Sorry for my lack of knowledge here. Victron mentions that a meter is optional. I do have a smartshunt that gives me info on what I consume, but I have a feeling that’s not what you mean?
What are the advantages of having a grid meter like the ET112? I just have a single 220V/45A phase.
For single phase, the ET112 would be just right … small and completely sufficient
Your supply cable must be clamped through it once … Don’t forget the miniature fuse …
There are plenty of connection drawings for the ET112 …
AND YOU MUST HAVE A GX UNIT … like the Venus,Cerbo(2) … or RaspberryMod
What kind of multi are you using?
or is the installation for a marina connection on a boat … because of the user name
I have a Multiplus 2000 VA 24V, 250Ah batteries, a Cerbo GX S, Smartshunt, SmartSolar 250/70 (3.75 kW). It’s been used as a backup for grid failures which happen multiple times a day. I’d like to use my solar more and discovered ESS. It’s a house, no boat.
I’m still getting my head around the grid feedback (which I don’t have a use for), but just wondering if my wiring will work.
Without a grid meter, am I risking feeding back all the PV power to the grid (next to my other loads in my house, which is fine of course) without limits? With a grid meter you can minimise this to a minimum?
Sorry if these are stupid questions. I didn’t feel like the Victron ESS manual answered it for me.
With normal ESS use, you feed exactly as much energy into the grid as your “house consumes” + - a few watts back and forth … cannot be changed technically.
May I ask where the Multi is operated … Legal regulations or not
I already have the emergency backup and now reduce the grid cost as a bonus.
When the sun is shining I would like the panels to supply power to the rest of the house which is not behind the Multiplus. When grid is lost we have our critical equipment running on battery.
From my understanding both should be possible with ESS. But you’re telling me I need a grid meter. (Although you haven’t said it directly, I feel the implication in your words).
May I ask what happens if you enable ESS without a meter?
Imagine a Dicso WITHOUT a bouncer … and in the morning you ask someone how many people are still inside … including information on how many people are in and out in total …
It doesn’t work because you don’t have a grid meter (bouncer).
How is the GX supposed to know how much the Multi should feed back? …
You can set a fixed value, but that makes no sense with alternating loads.
You need a grid meter or a grid sensor … which is not possible with your small Multi …
Have a look around for a 3000 Multi Plus2 … the prices are actually at rock bottom …
You need a meter installed before switch board ans set the grid metering to: external meter, then set the grid feed-in to off. Should be the end of it.
The easy way to meter the grid is install a shelly EM and follow this guide to get the data on the cerbo. If you install the ESS assistant and set a grid setpoint to 10 or 50 it will will maintain the power usage in the house at just above 0W.
There is the 1:1 rule, saying your max AC coupled PV power must not exceed your Multi’s nameplate power, 2000VA in your case. As you mentioned MPPTs, those and the panels feeding them do not count towards this (“DC coupled”).
However, the Multi converts the DC from the DC coupled panels to AC, so you’d never be able to use more than 2000VA/1600W from them.
So the question is, what are your loads? And what is the weather like, do you have direct sunshine every day or is there a rainy season with nothing but clouds (I remember seeing a travel video from Madagaskar with weather like that)? And how expensive are panels over there?
The Multiplus was acquired a few years ago with 2 gel batteries as a backup for the increased grid failures. I split my home electric system into a critical and non critical part. The 1600W capacity is more than enough for my critical loads. It’s mostly lights, a few outlets for laptop and phone charging and a fridge. On a normal day the critical loads consume 3kW. My total daily consumption is around 12kW.
Unfortunately the grid has further destabilised (between 12-18 hours of grid power per day) and I installed a Cerbo and a EasySolar with 3.75kW PV a few months ago. We have a lot of sun as we don’t live in the rain forest. In theory I should get around 16kW per day from my panels if I change to a 48V system.
The reason for the already installed PV is the future plan to change to a Multiplus 48/5000 (3000?) plus LiFePo4 batteries. But it’s another investment.
@Skipper : a quick note about units, and forgive me if this was a typo and you already know this.
You probably meant that your loads are 3kW, and your consumption is 12kWh - power is in W or kW, energy is in kWh. This time it was easy to grok, but you risk confusing us if the numbers were closer together.
On another topic that might be of interest …
If your max load is 3kw, and you have a 2kw inverter but you plan to upgrade to a 3kw or 5kw, then my point is moot, but to continue for academic discussion …
If your inverter was small and your load large, then because of the 1:1 rule, your inverter could be working hard all day and your system would still be importing grid power to top up.
In these cases, you can get around the 1:1 rule by moving some loads to DC. This puts the load outside the 1:1 rule. An example might be that your water heater has a 230v AC element, and runs on your normal circuits (i.e. from inverter or from grid) but this could be changed to a 48v DC element, so now when there is a lot of sun, and your inverter is converting 2kw of your solar into AC but there is maybe 1.5kw that can’t be used, this could be used as DC to heat your hot water.
The critical loads seem to be around 125W, totaling ~3kWh per day. The 12kWh mentioned appears to be the total house consumption, which they want to offset with 3.75kW of solar. If solar generates 16kWh daily, that should cover their loads.
Currently, it looks like the critical loads inverte is set to keep the batteries charged for the 12–18 hours of outages. To ensure reliability in bad weather, solar capacity should be ~4× daily consumption, and battery storage should be at least 2–4× daily consumption. The system should work well if they get the expected good weather.
Yes it’s 3kWh daily consumption on the critical loads. Closer to 4kWh actually when I look at my last week. 12kWh is my average daily consumption for the whole house. Apologies for the confusion.
That’s how I calculated it. 3-4kWh consumption per day, my yield is between 15-19kWh depending on the season according to mppt.victronenergy.com.
If you want to wipe out your bills I would get the 450/100. I have East and West facing arrays 7x390w panels per string with a 5460W peak for 100A of charging. The system does 30kwh a day on a good day and 15kwh when its cloudy. East and west facing means I get good production in the morning and the afternoon. I also have grid-tied north-facing PV solar inverters.
I would also look at a battery size of around 30kwh.
I’m afraid I don’t know the answer to your question, but I thought I’d let you know that at the end of every day, I see how much energy is available via VRM Portal - Victron Energy…, and then set grid export using http://192.168.178.41/ “Grid Setpoint” (setting it to a negative value). My utility limits me to 5kW export, which I intend to do 24 hours/day.
