Device are turned on even if their is not enough solar production

[julianwachholz]

I have a very simple device configured with 2000W power (heat pump water heater). The Solar Optimizer config is set up correctly, the service shows the correct numbers for power production etc.
I've noticed it again and again now that each morning the heat pump starts way too early. Today SO enabled the switch at 08:40 when power production (not even excess power) was just 1700W. What is going on here?

Blue: inverter power
Yellow: Net power consumption (same sensor used in SO config)

As you can see after the heat pump ramps up, I no longer have excess power but have to import it again.

My buy and sell prices are 0.27 and 0.11 respectively, my primary goal is to maximize self consumption, not cost.

Device configuration

[jmcollin78]

Hello,

This is totally possible by construction of the algorithm.
Importing energy from the grid have a cost: 0.11 (if I understand your config),
Exporting energy to the grid have a cost: 0.27 (If I understand)

The goals of SO is to maximize the use of the solar power by evaluation different configuration of a cost function.
The cost function is evaluated as: import power x import price + export power x export price.

So in your case, it costs less to activate and import a few than not activate and export more.

To change this behavior, you have to change your prices.

If you want to avoid importing energy, set the import cost much higher than the export price. With your configuration, importing cost 0.11 so it is better to import than exports.

[julianwachholz]

Thank you for the reply, I had a feeling it's because of the price.
We pay 0.27 for importing, I receive 0.11 credit for exporting.
Both numbers should be positive in the config, correct?

I understand in other regions the differences are much larger (I even put day/night tariffs but they only change by 0.02) which may have better results with the algorithm.

[julianwachholz]

I changed the prices to 100 for importing and 0 for exporting which would be a super extreme case where it's prohibitively expensive to buy more power, right?
This morning it again enabled the device at around 1700W PV production (and just 1200W excess)...

I also feel like there really ought to be a waiting period i.e. wait until we have X excess for at least Y amount of time. I know the "smooth" option should probably take care of this, but it really doesn't seem to be doing anything. My refresh period is 5 minutes btw.

[jmcollin78]

0 is not a good value. It should be > 0.

[julianwachholz]

This was it! Now the device only activated once there was more than 2000W excess!

Now, I believe this isn't mentioned anywhere and it's also quite common that households don't get any reimbursement for their feed-in. This should be caught in the algorithm...

[jmcollin78]

In the documentation:

A sensor or input_number that provides the cost of imported kWh (required: strictly positive number).
A sensor or input_number that provides the price of exported kWh (required: strictly positive number). If there is no resale contract, the same value/sensor as the imported cost can be used. Do not set it to 0, as it would distort the algorithm.

[jmcollin78]

I pin this discussion because it is very important to understand how it works.