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Example below of how to achieve this:
what i want it to do is control whether to export to grid or charge the batteries based on time of day and battery SOC - and i want to be able to modify these 2 parameters easily
e.g.
If SOC > 50% and time is after 7pm send PV to grid.
Hi @zed must
Not sure I'll have time but thought I'd ask a few questions (that I imagine anyone willing to help might want to ask anyway which might give people the extra info they need to offer their services).
1. What is your plan for how to adjust the parameters? Do you need/want a dashboard created in node red to adjust these, or do you have another system ie homeassistant/openhab that you'd want to utilise to update the SoC, time and i assume charge/discharge.
2. How is the system currently configured, is the solar connected via charge controller (DC coupled) or via Grid tied inverter (AC coupled) or do you have both. (If it's just AC coupled there's a faster way to code it up I believe)
3. When you say export to grid which of the below do you mean (or do you mean a mix in which case another few parameters might be needed to select which one).
4. In terms of turning off this feature. (less applicable if your answer to 3 is excess solar only)
ie feature turned on if SoC > 50% after 7pm.
do you want off to occur only when SoC < 50% or at 5am or after x hours.
HI Matt, thanks for your interest.
1. Ideally we would be able to adjust the parameter in node red. Not sure i need a dashboard - i can just about get my way around node red so im sure if you tell me which nodes to edit i can do that myself.
2.We have both DC coupled solar and AC coupled wind through a Quattro. See screenshot below.
3. we would want to:
During certain hours when battery SOC meets a set value.
4. ideally we would be able to have multiple conditions/time slots, but not the end of the world if there is only a couple. So that the feature would turn on and off automatically when conditions are not met, ie
from 8am-10am, if SOC>90%, send all generated power to grid (so that when SOC drops <90%, power goes back to batteries
from 10am-2pm, if SOC>70%, send all generated power to grid
from 2pm-7pm, if SOC>50%, send all generated power to grid
from 7pm-11pm, if SOC>30%, send all generated power to grid
Where i can change the hours and the SOC for each rule. But they should all work the same i.e. on when conditions are met (i.e. send to grid) and off when conditions are not med (i.e. charge the batteries).
And one final complication - we aren't allowed to export more than 6kw, which is currently set up as a limit in the ESS settings. However if using a node red setup instead, we would need to make sure that if we are in 'send all generated power to grid mode', that any power generated over 6kw doesnt get wasted and instead goes to the batteries i.e. 6kw to grid, balance to batteries.
Hope all that makes sense and isn't too difficult to set up.
Thx
Making a fully polished system with dashboards (ie an interface where you just fill in a text box to adjust parameters) is time consuming. If however you just want this:
from 10am-2pm, if SOC>70%, send all generated power to grid from 2pm-7pm, if SOC>50%, send all generated power to grid from 7pm-11pm, if SOC>30%, send all generated power to grid
Written in code. I can send you that and you can implement it for free.
In terms of the 6kw limit, id leave that in ESS, feels safer there in native very well tested code.
Here's some code:
I know the below is instructions rather than an easy install but it's free....
EDIT: You might have to change this is you ever want to manually make grid setpoint greater than 0. As this code will override it back to 0.
You need to do a few things first:
1. Get the data from victron nodes:
So you need to find the node that outputs the AC Solar data (PV Inverter node, then select measurement of power) as well as the DC solar data (likely Solar charger node and select measurement of PV Power). If you've got multiple MPPTs let me know i can edit the code to have multiple dcSolar variables.
And finally you do the same with State of charge data (likely from battery monitor node selecting measurement state of charge %).
2. These data nodes need to be passed into their own change nodes so you can set the topic of the message (this tells the function what type of info it's received.
It'll look like this:
With the inside of the change node looking like this:
You repeat this process for the DC solar but change the topic name in the change node to dcSolar and soc for battery monitor
You string them together like this:
Function 2:
//setting up time variables
var currentTime = new Date();
var hours = currentTime.getHours();
var minutes = currentTime.getMinutes();
//setting up data variables. If using up to date venus os you could get these directly via global context.
var soc = global.get('soc');
var acSolar = global.get('acSolar');
var dcSolar = global.get('dcSolar');
var gridSetpoint = global.get('gridSetpoint');
//setting soc variable depending on inputs from flows
if (msg.topic === "soc") {
soc = msg.payload; // Extract payload from input 1
global.set('soc', soc);
}
if (msg.topic === "acSolar") {
acSolar = msg.payload; // Extract payload from input 2
global.set('acSolar', acSolar);
}
if (msg.topic === "dcSolar") {
dcSolar = msg.payload; // Extract payload from input 3
global.set('dcSolar', dcSolar);
}
//this is used to check if gridsetpoint is already 0, if it is then we won't bother updating it.
if (msg.topic === "gridSetpoint") {
gridSetpoint = msg.payload;
global.set('gridSetpoint', gridSetpoint);
}
if (msg.topic === "acLoad") {
acLoad = msg.payload; // Extract payload from input 2
global.set('acLoad ', acLoad);
}
//two examples of times
if (hours >= 10 && hours < 14) { //if time is between 10am-1.59pm
if (soc > 70 && acLoads < 10000) { //if state of charge is above 70%
//return the new grid setpoint
gridSetpoint = -Math.min(acSolar + dcSolar, 6000);
} else {
gridSetpoint = 0;
}
} else if (hours >= 14 && hours < 19) { //if time is between 2pm and 6.59pm
if (soc > 50 && acLoads < 10000) { //if state of charge is above 50%
//return the new grid setpoint
gridSetpoint = -Math.min(acSolar + dcSolar, 6000);
} else {
gridSetpoint = 0;
}
} else if (hours >= 19 && hours < 23) { //if time is between 7pm and 10.59pm
if (soc > 30 && acLoads < 10000) { //if state of charge is above 30%
//return the new grid setpoint
gridSetpoint = -Math.min(acSolar + dcSolar, 6000);
} else {
gridSetpoint = 0;
}
} else {
gridSetpoint = 0;
}
if (gridSetpoint !== global.get('gridSetpoint')) { // Check if gridSetpoint is going to change
global.set('gridSetpoint', Math.min(gridSetpoint, 0));
msg.payload = Math.min(gridSetpoint, 0);
return msg;
}
At this stage the function will output a message of what to set the gridsetpoint to. However before you pass this function into the ESS gridsetpoint node (to set the grid setpoint). You should test the code works as expected on your system/there aren't any bugs in it. To do this you should pass function into a debug node like below. And watch the outputs at various times of the day. Once you're happy that the function is outputing the correct negative number at all points in the day then you can pass the function into the ESS grid setpoint node.
I've hopefully written the code so you can see what hours you need to change and SoC to get the desired times.
As i said the debug would be replaced with grid set point node once you've confirmed function 2 is outputing what you expect.
wow, thanks so much Matt! i appreciate you doing this for free but still happy to pay you something, or if you want to nominate a charity i would be happy to make a donation on your behalf. thx again
Update: so ive got wind, pv and soc all coming through, but when you said the system would give a msg - im not sure if i have done something wrong? I put all your code into the OnStart tab of node 2 is that correct?
Hi Matt,
The code has been working great but recently i have noticed a few times that even though conditions have been met, and gridsetpoint is -6000, the system is not selling back to the grid but is charging the batteries instead. Like right now. Any idea why this would happen? I am on 'optimized without battery life' so that is not the reason.
And in trying to fix it i have managed to break it. I went back to your original code but it's no longer changing the grid setpoint like it used to. Dont know where i have gone wrong but i suspect a recent victron update has changed something ( All i am trying to do now is set the gridpoint to -6000 at certain times of the day depending on SOC - without any of the inputs from solar) it just doesnt work any more
Clarity needed, Your example of
If SOC > 50% and time is after 7pm send PV to grid.
Do you have PV after 7pm?
1) Are you only feeding in PV or are you wanting to feed-in stored battery energy during peak periods where the feed-in tariff is at its highest then recharge the batteries during off peak at the lowest tariff.
2) do you want to limit the maximum feed-in power.
Settting the minimum SOC through the node red dashboard is easy and you can set as many set points as you wish, I change the minimum SOC every hour to crate a slow discharge through the night to make sure I don’t deplete the battery in the first 3 hours. I then bring up the minimum SOC hourly during the day which usually lags the actual SOC on sunny days how ever on over cast days the internal battery charger initializes to charge from the grid if there is insufficient Solar on overcast mornings, after mid day when the sun is up high the actual SOC overtakes the hourly minimum SOC again, so no charging from the grid takes place.
Setting PV Feed-in at different times as well as the feed-in amount in watts is also quite easy, Discharging the batteries into the grid is also easy to do by just setting a negative grid set point which will deactivate when the minimum SOC is reached.
The problem comes in when you have to limit the maximum feed-in power from the batteries. It can be done, I have done it but the amount of writes to the GX flash memory is quite a lot, every 2 or 3 seconds you need to write a new grid set point taking into account your current load on the AC-out of the inverter, AC-in to calculate internal loses as well as include any grid loads before the inverter if you have an external energy meter who’s roll is set as grid meter
I run NR on a seperate machine based on an SSD so not worried about write cycles, but I am concerned about the GX's storage longevity...
I did see someone investigating/asking, but no official answer yet by the looks of it:
https://community.victronenergy.com/questions/237446/cerbogx-flash-lifetime-when-writing-setting-each-m.html
I'm honestly not sure how persistence of data is handled. Like i know dbus runs in ram. However does every change to dbus of settings get written to file? That I'm unsure of. I think it would have to write to flash everytime, i cant think of a way around it, trying to write to non-volatile memory on shutdown wouldnt be reliable enough.
I'll have a dig on their github page but not sure.
I run on a pi so never really thought about it.
EDIT:
I did some digging it does write to flash every time settings are changed. Got me thinking is editing gridsetpoint/max discharge or anything that appears in com.victronenergy.settings a bad idea.
I did look around in dbus and think maybe editting hub4 directly might be away around it but it looks like hub4 settings are also stored in the settings.xml
I'm not sure of a work around to minimize flash implications via node red. I would instead maybe look to edit the system calculations driver (or whatever driver handles the ESS/Hub4 inverter output changing to balance grid to gridsetpoint) to have an additional if statement that gets a new variable gridsetpoint2DBUS in my example but same principle for any non-volatile setting
This new variable would be the same as gridsetpoint but would be stored in a new custom dbus service that is purely volatile/doesnt write to settings.xml
Then you'd tweak the system driver to factor in the new variable the exact same way native grid setpoint is handled.
Way more involved and harder to manage over updates (so im not going to try) but this would be my guess about how to do it if folk really wanted to.
(Happy to be told im wrong/there's a better way. please tell me if there is as I'd be very interested)
something like
if gridSetpoint2DBUS is not None: //or 0 maybe if you set dbus default to 0
//do same calc system would normally do but tweak for gridSetpoint2DBUS value
My guess would be the settings like grid setpoint wouldn't be written to flash on inverter as you need gx device to run ess. If it was stored on inverter flash then surely they wouldn't need additional gx device.
So I reckon it's only the gx's flash that's impact and the inverter would read live
I wonder if I could do it?
Could you please update the codes for three phase pv inverter and two MPPT
I think it's okay this time
Hi @avukat38
So first thing to flag is you've got 2 smart solars going into one dcSolar change node.
If you do this then the function will use either smartsolar1 or smartsolar2 (it wont add them together like i imagine you're hoping it will).
You'll need to add another change node. ie change topic to dcSolar1 thats for smartSolar1 and then similarly dcSolar2 for smartsolar2.
Then edit the function to do something like:
if (msg.topic === "dcSolar1") {
dcSolar1 = msg.payload; // Extract payload from input 3
global.set('dcSolar1', dcSolar1);
}
if (msg.topic === "dcSolar2") {
dcSolar2 = msg.payload; // Extract payload from input 3
global.set('dcSolar2', dcSolar2);
}
var dcSolar = global.get("dcSolar1") + global.get("dcSolar2");
The other question I have is how do you want the three phase setup to work?
Do you need per phase control? I'm not as familiar with 3 phase installs so i'll need to read up on whether you can control per phase grid setpoints. ie do you use "Total of all phases" or "Individual phase" in ESS settings.
Do I need to do something about AC load?
The original poster said they needed a criteria where if their acLoads were greater than 10kw then they didnt want the gridsetpoint to be changed.
If you dont need that criteria you can remove:
if (msg.topic === "acLoad") {
acLoad = msg.payload; // Extract payload from input 2
global.set('acLoad ', acLoad);
}
and remove any references of acLoads from any of the if statements.
If however you do want that criteria you'll need to pass acLoads data into the function (the same way you have with soc and dcLoads etc)
Thank you very much
Bu hatanın ne olduğunu merak ediyorum?
You've correctly remove the acLoad variable definition but you've not removed acLoads from the if statements. The error code is letting you know the error is on line 44, in the 19th position which is where acLoads is used in the code even though you've removed the definition of the variable.
ie You've got:
if(soc >70 && acLoads <10000){
.....
If you're not using acLoads you need to remove all references to it ie change this to:
if(soc > 70) {
....
You have to do that everywhere there's reference to acLoads.
Thank you very much, thanks to you I learned something about node-red. https://community.victronenergy.com/questions/278498/how-can-i-program-dess.html?childToView=279392#comment-279392 I tried to give a flow to the question I asked here. Is it true?
Do you want to try post the whole code on here. I can tweak it for you and explain what I change.
The bits that stand out are lines 10, 14 and 18
You've updated the code to get the acLoad2 but you've forgotten to change lines 10, 14 and 18 to change the variable from dcSolar1 to be acLoad1 or acLoad2 or acLoad3 depending on which case you're in.
//if you're using old venus os you need the below. if not you can just read these varibales from the global context
var acLoad = global.get("acLoad1") + global.get("acLoad2") + global.get("acLoad3");
var acSolar = global.get('acSolar');
var dcSolar = global.get("dcSolar1") + global.get("dcSolar2");
var gridSetpoint = global.get('gridSetpoint');
var exported= global.get('exported');
//setting soc variable depending on inputs from flows
if (msg.topic === "acLoad1") {
acload1 = msg.payload; // Extract payload from input 1
global.set('acLoad1', acLoad1);
}
if (msg.topic === "acLoad2") {
acLoad2 = msg.payload; // Extract payload from input 1
global.set('acLoad2', acLoad2);
}
if (msg.topic === "acLoad3") {
acLoad3 = msg.payload; // Extract payload from input 1
global.set('acLoad3', acLoad3);
}
//setting soc variable depending on inputs from flows
if (msg.topic === "exported") {
exported = msg.payload; // Extract payload from input 1
global.set('exported', exported);
}
if (msg.topic === "acSolar") {
acSolar = msg.payload; // Extract payload from input 2
global.set('acSolar', acSolar);
}
if (msg.topic === "dcSolar1") {
dcSolar1 = msg.payload; // Extract payload from input 3
global.set('dcSolar1', dcSolar1);
}
if (msg.topic === "dcSolar2") {
dcSolar2 = msg.payload; // Extract payload from input 3
global.set('dcSolar2', dcSolar2);
}
//this is used to check if gridsetpoint is already 0, if it is then we won't bother updating it.
if (msg.topic === "gridSetpoint") {
gridSetpoint = msg.payload;
global.set('gridSetpoint', gridSetpoint);
}
if (msg.topic === "acLoad") {
acLoad = msg.payload; // Extract payload from input 2
global.set('acLoad ', acLoad);
}
//The main logic.
if (exported < 10000) {
gridSetpoint = acLoads - acSolar + dcSolar;
} else {
gridSetpoint = 0;
}
if (gridSetpoint !== global.get('gridSetpoint')) { // Check if gridSetpoint is going to change
global.set('gridSetpoint', Math.min(gridSetpoint, 0));
msg.payload = Math.min(gridSetpoint, 0);
return msg;
}
I spotted one typo acloads1 should be acLoads1, the rest looks ok to me. Unless you're getting more errors?
The other thing I'd mention is you've not setup exported in this function, it's defined but it wont have a value written to it (unless you're doing that in another function).
You'll either need to it to this function somehow or you can use another flow to get the data in because you're using global.
Because you're using global you can use a completely different flow to get the data into global just need to set it like
global.set('exported',msg.payload);
This is assuming you use a new flow and the only message being passed in is the total exported figure.
var acLoad = global.get("acLoad1") + global.get("acLoad2") + global.get("acLoad3");
var acSolar = global.get('acSolar');
var dcSolar = global.get("dcSolar1") + global.get("dcSolar2");
var gridSetpoint = global.get('gridSetpoint');
var exported= global.get('exported');
//setting soc variable depending on inputs from flows
if (msg.topic === "acLoad1") {
acLoad1 = msg.payload; // Extract payload from input 1
global.set('acLoad1', acLoad1);
}
if (msg.topic === "acLoad2") {
acLoad2 = msg.payload; // Extract payload from input 1
global.set('acLoad2', acLoad2);
}
if (msg.topic === "acLoad3") {
acLoad3 = msg.payload; // Extract payload from input 1
global.set('acLoad3', acLoad3);
}
//setting soc variable depending on inputs from flows
if (msg.topic === "exported") {
exported = msg.payload; // Extract payload from input 1
global.set('exported', exported);
}
if (msg.topic === "acSolar") {
acSolar = msg.payload; // Extract payload from input 2
global.set('acSolar', acSolar);
}
if (msg.topic === "dcSolar1") {
dcSolar1 = msg.payload; // Extract payload from input 3
global.set('dcSolar1', dcSolar1);
}
if (msg.topic === "dcSolar2") {
dcSolar2 = msg.payload; // Extract payload from input 3
global.set('dcSolar2', dcSolar2);
}
//this is used to check if gridsetpoint is already 0, if it is then we won't bother updating it.
if (msg.topic === "gridSetpoint") {
gridSetpoint = msg.payload;
global.set('gridSetpoint', gridSetpoint);
}
if (msg.topic === "acLoad") {
acLoad = msg.payload; // Extract payload from input 2
global.set('acLoad ', acLoad);
}
//The main logic.
if (exported < 10000) {
gridSetpoint = acLoads - acSolar + dcSolar;
} else {
gridSetpoint = 0;
}
if (gridSetpoint !== global.get('gridSetpoint')) { // Check if gridSetpoint is going to change
global.set('gridSetpoint', Math.min(gridSetpoint, 0));
msg.payload = Math.min(gridSetpoint, 0);
return msg;
}
debug1 no longer gives any output
This is likely because exported is undefined....
so the final if statement:
if(exported < 10000)
is the same as saying
if(undefined < 10000) and undefined is not less than 10000 in javascript.
So as soon as you defined exported to be a number it should work. If not you'll have to add in some debugging in the function to see what's going on in more detail but my guess is exported being undefined is the issue
To check if i'm right or not you could add this to the bottom of the funciton:
else{
msg.payload = 'hello';
return msg;
}
if debug1 then outputs hello then that's proved it's because exported is undefined.
I never understood this
So you're trying to get your code to adjust grid setpoint until it's exported more than 10,000
So you're written the if statement to say if exported <10000) then adjust gridsetpoint.
However the variable exported you havent written a value to. so export = undefined.
So the code is trying to do:
if (undefined<10000)
which is returning the result false and setting gridsetpoint to 0. If gridsetpoint is 0 and hasnt changed the function doesnt output anything.
What you need to do is write a value to exported. Which is what is missing from your flows at the moment.
You need to find the data node for exported power and write it to the global variable exported. (the same as what you've done for soc, dcSolar acLoads etc but you now need to do it for exported.
Then your code will run at the moment grid setpoint is just being set to 0 and never changing.
Now it seems like the debug data is wrong
I'm not sure why it's outputting those messages. You're not returning the msg unless
Im not sure that EM24 is the right metric for exported but dont think that would cause the debug issue you're seeing.
I thought the debug was going to be connected to acLoad2 and acLoad3 to get those messages coming out.
However I spotted a few more typos acLoad instead of acLoads:
var acSolar = global.get('acSolar');
var gridSetpoint = global.get('gridSetpoint');
var exported= global.get('exported');
//setting soc variable depending on inputs from flows
if (msg.topic === "acLoad1") {
acLoad1 = msg.payload; // Extract payload from input 1
global.set('acLoad1', acLoad1);
}
if (msg.topic === "acLoad2") {
acLoad2 = msg.payload; // Extract payload from input 1
global.set('acLoad2', acLoad2);
}
if (msg.topic === "acLoad3") {
acLoad3 = msg.payload; // Extract payload from input 1
global.set('acLoad3', acLoad3);
}
//setting soc variable depending on inputs from flows
if (msg.topic === "exported") {
exported = msg.payload; // Extract payload from input 1
global.set('exported', exported);
}
if (msg.topic === "acSolar") {
acSolar = msg.payload; // Extract payload from input 2
global.set('acSolar', acSolar);
}
if (msg.topic === "dcSolar1") {
dcSolar1 = msg.payload; // Extract payload from input 3
global.set('dcSolar1', dcSolar1);
}
if (msg.topic === "dcSolar2") {
dcSolar2 = msg.payload; // Extract payload from input 3
global.set('dcSolar2', dcSolar2);
}
//this is used to check if gridsetpoint is already 0, if it is then we won't bother updating it.
if (msg.topic === "gridSetpoint") {
gridSetpoint = msg.payload;
global.set('gridSetpoint', gridSetpoint);
}
if (msg.topic === "acLoad") {
acLoad = msg.payload; // Extract payload from input 2
global.set('acLoad ', acLoad);
}
var dcSolar = global.get("dcSolar1") + global.get("dcSolar2");
var acLoad = global.get("acLoad1") + global.get("acLoad2") + global.get("acLoad3");
//The main logic.
if (exported < 10000) {
gridSetpoint = acLoad - acSolar + dcSolar;
} else {
gridSetpoint = 0;
}
if (gridSetpoint !== global.get('gridSetpoint')) { // Check if gridSetpoint is going to change
global.set('gridSetpoint', Math.min(gridSetpoint, 0));
msg.payload = Math.min(gridSetpoint, 0);
return msg;
}
heres my solution for this timed export if any1 is looking for this.
also if u guys are connecting all the change nodes into function node it will be called very very often(i had very weird results with this) rather get an inject node on repeat 1s for ex. this solution also gets solar forecast from vrm and if it is greater then 30kwh it export 70% of excees power into grid and if less only 40%. I do this kind of control because i got ~14kwp of solar and only 3x3000VA multipluses which caps at 10:00(-6300W) and solar at 8kw and its constantly at 8kw for few hours. this way i can get up to 12kw power from solar since battery is able to absorb some additional power.
this is function 2:
var ac = global.get('AcCons');
var sp = global.get('SolarPower');
var frcast = global.get('Forecast');
var sub = 0;
let time = new Date();
let hour = time.getHours();
let mult = 0.4;
if (frcast > 30){
mult = 0.7;
}
//ac !== 0 && sp !== 0
if (hour<=10 && hour>=7) {
// Perform the subtraction and subtract 1000
sub = sp-ac;
sub *= mult;
sub = -Math.round(sub,0);
// Create a new message object to send only the subtraction result
let newMsg = {
topic: "SubtractionResult",
payload: sub
};
newMsg.complete = true;
// Return the new message object
return newMsg;
} else {
let newMsg = {
topic: "SubtractionResult",
payload: 0
};
// If either AC consumption or solar power value is missing, do nothing
return newMsg;
}
this is function 3 :
let tmp = Math.round(msg.payload.totals.solar_yield_forecast/1000,0);
global.set('Forecast',tmp)
msg.payload = tmp;
return msg;
Brilliant thread this. Well done all. I guess we are all learning there are many different ways to get to the same output, that's the beauty and power of Node Red. Well done Matt great advice and examples too.
