Solar predictions and curtailment, how to handle?

[scruysberghs]

Starting this topic after a remark from @davidusb-geek on an issue a while back:

"For now the adjustment is based on historic values of both the real PV power and the forecasts. So it will consider any curtailment events as these are not filtered. But wouldn't it be nice to have a prediction of curtailment events integrated into the PV forecast?
We can open a discussion thread for this."

->
I’m running an MPC optimiser every two minutes in Home Assistant. My original approach was to feed it the Open-Meteo solar forecast (pv_power_forecast), supplemented by sensor.energy_production_today. As the first element of the forecast array I used the inverter’s actual output—but this caused the optimizer to toggle curtailment on and off each run when emhass was controlling the inverter.

To fix that, I changed the first array element to:

"pv_power_forecast": [{{ states('sensor.solar') | int(0) + states('sensor.p_pv_curtailment') | int(0) }},{% for i in range(etc etc , the values from the sensor.energy_production_today 

Here, the first value is actual inverter production + emhass curtailment power, so the optimizer sees the “true” PV output.

Now that we can use "set_use_adjusted_pv": true to invoke an ML model that reconciles sensor.p_pv_forecast with sensor.solar, I suspect we’ll need a different strategy for handling curtailment in our forecasts.

How are you managing solar predictions and curtailment in your setups?

[scruysberghs]

On my test system here there are some unexplainable things in my mpc results with regards to solar predictions right now

I wonder where these values for p_pv_curtailment and p_pv_forecast come from (1816W) vs passed pv_power_forecast is 5928W.
use adjusted_pv is off for now.
Also, with prices (load and cost) being very negative right now I would expext 100% curtailment, battery 0, and use from grid all the way to the set max_power_from_grid value.

[purcell-lab]

Also, with prices (load and cost) being very negative right now I would expext 100% curtailment, battery 0, and use from grid all the way to the set max_power_from_grid value.

I see 100% pv_curtailment with negative prices from 11am tomorrow:

[scruysberghs]

@davidusb-geek , I explained the issue the claude.ai code and had him/it create a PR, let me know what you think or if you see another option?

[sampathdassanayake]

I've also noticed that emhass suggests curtailing when import price is positive. My optimisation model is profit. Hence I don't get why it would suggest curtailing when exporting would generate revenue