set calculated values like Feed-in or Consumption power as MQTT threshold
I have an inverter what has one SMART Relay and SMART Load management option. You can set:
"Feed-in" threshold where smart relay is switched on.. (if there is enough sun shine, hot water water tank's heating is switched on with smart relay - increasing self usage instead of selling surplus power for 5HUF/kwh and buying for 40HUF if needed later in Hungary..)
"Operation time" to avoid switch on/off smart relay too frequently if weather is fast changing because of clouds.. (you can set for example 10 minutes minimum operation time once Feed-in threshold crossed
"Consumption off" you can switch off Smart relay at predefined consumption level
"SOC off" you can switch off Smart relay at predefined SOC level
"Forced operation time" like "16.00-17.00", meaning if the weather was bad on the day, you can overwrite with settings above and force to give supply for hot water thank to get warmed up..
This is a very good smart load management, the only on disadvantage of it that there is one Smart Relay in the inverter and you can control only one device but you have many (like water tank heating, air condition, EV charge etc..)
iammeter cloud has MQTT support, what means, if settings above like calculated threshold settings (Feed-in, Consumption etc.) would be available in iammeter MQTT, more devices could be controlled, settings Feed-in levels for different devices gradually..
I should admit it is similar to your WPC3700 solution in case of hot water thank heating, but with MQTT. (less accurate, improves significantly but provides less self consumptions rate what could be achieved with WPC3700 - but ROI is good as nothing else needed than a MQTT controlled Tasmota smart plug) on other hand it can be used for Air condition and EV charger control as well (with an MQTT command and a Plug..)
If to implement the solution above is too complex, enable to set calculated values like Feed-in or Consumption power as MQTT threshold would be a significant improvement as well..
Please refer to
IAMMETER does support triggering Tasmota on/off via MQTT.
However, based on our current understanding, simply toggling the relay on and off is not an optimal way to utilize solar surplus.
- The relay operates in a binary mode (on/off) and cannot adjust power linearly.
- It will only turn on when the solar surplus exceeds a predefined threshold, meaning it cannot dynamically track real-time solar surplus.
- Since frequent relay switching is not ideal, it may not respond effectively to fluctuations in solar generation.
If you have a tank boiler, we strongly recommend trying the WPC3700, even though it is more expensive than a Tasmota relay.
Right now, there is a special promotion: PV Heater Control System Promotion.
For example, if it helps you utilize 10 kWh of solar surplus per day, you could save:
(0.4HUF−0.05HUF)×10=3.5HUF per day, which is approximately 0.96 USD.
This means you could recover your investment in about 200 days.
Of course, if you are already effectively utilizing your solar surplus through other methods, the WPC3700 may not provide additional savings.
Hi Laoliu,
I use MQTT from iammeter to tiggering Tasmota plug already, thanks for your update.
No question that WPC3700 is superior compered to the solution I offered to consider to implement
The main difference between suggested solution and current available triggering options you can select is the threshold what you can set in MQTT command in iammeter right now. (it is value of A-B-C CTs..)
My suggestion is to enable in iammeter to set calculated values in MQTT as a threshold, like Feed-in (A -available already) or Consumption (A minus C in single phase environment of WEN 3080T.., what you can't set now ) etc..
and you are absolutely right, this solution can't "dynamically track real-time solar surplus."- the advantage of WPC3700 is clear - in fast changing weather conditions, like sunshine and fast moving could especially.., on other hand WPC3700 is working with "real resistance" consumer devices like "hot water thank" perfectly, but - as far as I understood it can't control electrical devices like normal Air condition.. (and I am not sure about EV chargers as I don't have any yet)
I understand that to implement the solution I suggested is not just a technical challenge (this is the easier part I think) but business impact should be considered as well.. (so nothing more than an idea - thanks for your fast response..)
Have a nice day!
Gabor
Hi Gabor,
We can consider adding new logic for the trigger threshold, such as using a calculated value as the trigger threshold.
However, we do not see a clear benefit in doing so. Based on our understanding, only one parameter is necessary: solar surplus power.
When a meter (or one phase of a three-phase meter) is installed on the grid side, it monitors grid power (whether consumed from or exported to the grid). This value directly reflects the solar surplus being exported. We use this value as the trigger threshold to operate loads accordingly.
If we add the calculated value as the trigger value ,what is the specific meaning?
Please show me a specific usage that need to trigger the operation by the calculated value?
Thanks
Laoliu
Hi Laoliu,
I understand your point, but Imagine a situation PLS, where base load is 0.5kw, the water thank needs 2kw and air-conditions needs 2.5kw. We have an inverter what can produce 5kw in peak.. So if you set up feed in threshold to 2.5kw(0.5 base load + 2kw the water tank needs), than heating of water will start at 2.5kw inverter production and the feed-in will drop to 0.5kw immediately after "switch on" (until hot water tank is warmed up)
What to do with the air condition in such case...? what threshold to set for it to get it working..? if you set 2.5kw for it as well, than at 2.5kw inverter production the hot water tank and the air-condition together would drop the feed in to negative (buy)as 2.5kw inverter-0.5-2-2.5=-2.5 kw.. what we want to avoid in all circumstances.. what ever you set you can't avoid that they operate parallel and you buy electricity...If you would set up 5kw feed-in threshold for the Aircondition to avoid that in this case it would never start to work...
but if you have calculated threshold like consumption.. You can set hot water threshold to 2.5kw "ON" and consumption 0.6kw "OFF" meaning once hot water is heated up -and consumption drops- hot water plug is switched "OFF". We can set 3kw feed-in threshold for air condition in such now(anything slightly above hot water threshold, to ensure that hot water is prioritized). Air condition won't be switched on with these settings until hot water is not heated up, but will do right after hot water is warmed up and there is no hot water thank consumption anymore..
Inverter production below 2.5kw - neither hot water tank nor air-condition works
Inverter production 2.5kw-3kw - hot water tank will work until feed-in larger than 2.5kw and consumption is more than 0.6kw (meaning hot water thank is heating), air-condition wont work
Inverter production is above 3kw... - hot water than will be switched on until heating and won't work when no heating(consumption drops to normal which is 0.5kw(below 0.6kwh). Air condition will start only, if feed-in will be 3kw-0.5kw=2.5kw (hot water heated)
without the "calculated threshold" like consumption threshold we would have two options a) buy electricity or b) air-condition never starts...
"minimum operation time" would be needed just to avoid to frequent switch ON/OFF.
best would be if there could be a simple logic set for two MQTT threshold like "if feed-in is larger AND/OR consumption is lower".. It would be easier to understand
(SOC value could be a threshold as well once available...)
Also important to be able to set a "forced operation period" for such cases - without any threshold, just for a period... (if weather is bad and 2.5kw "hot water (feed-in) threshold" will be not reached, both devices (hot water tank/Air condition) still will need to operate few hours daily... The "forced operation period would ensure that..)
With" Smart relay " option of an inverter you can't solve this as there are two (or even more devices) - MQTT frm cloud could make it possible.. Imagine a situation that with such setting, - as sun is raising - you fist support the base load, than heat up the water, than cools your house, than loads your car... With this "calculated threshold solution" you can ensure that next device starts only, once the higher prioritized(lower feed-in threshold) device completed it's heating/cooling/or loading task and does not working on that(consumption as calculated threshold drops back)
Sorry if I was long, I hope I managed to explain..
Thanks
Gabor
Maybe one more comment to above. Anything what ensures that after feed-in power is enough, the large loads - like Battery charging, hot water thank heating, air-condition, EV charger - starts after each other (but never parallel to avoid import) is welcome. I did not have better idea than to control it with MQTT feed-in and consumption thresholds, but it is a kind of workaround and I can imagine that there are better solutions for that... (if you know one, let me know PLS, I would like to implement)
Have a nice day
Gabor
Hi Gabor,
Sorry for my late replies. I missed this topic before.
I am a little confused.
".. You can set hot water threshold to 2.5kw "ON" and consumption 0.6kw "OFF" meaning once hot water is heated up -and consumption drops- hot water plug is switched "OFF". "
"Inverter production 2.5kw-3kw - hot water tank will work until feed-in larger than 2.5kw and consumption is more than 0.6kw (meaning hot water hank is heating), air-condition wont work"
Please help me to explain, what is the "consumption" mean?
whether it is measured by meter directly or a calculated value?
And if you only use such simple logic below, what is the problem ?
1 trigger on the boiler when the feedin power is greater than 2.5kw, then the feedin power would be around 0 .
2 after some time when the boiler heating the water complete, it would stop working ,and the power would be zero ,then the feedin power would be nearly the inverter output again ,when it is greater than 3kw, turn on the Air conditioner. Thne the feedin power would be around zero again.
Hi Laoliu,
give me some time PLS and let me test my "theory" more deeply before I answer (it is possible that you have right and my goal can be solved without calculated threshold). I try to link a Shelly switch now to iammeter and control it with MQTT, I have raised about that parallel - thanks if you can help thee - , once it is working I will test it and come back to you. (Than with two of my switches (a Tasmota what is working already and Shelly) I will test different scenarios. .
Time doesn't matter, I am thankful for your answers (both Wem3080T and the integrated Solinteg inverter works perfectly in iammeter cloud, I am just trying out ways to maximise the self consumtion now..
Thanks
Gabor