ESS - Portugal price mismatch

[lrascao (Luis Rascão)]

Hi all,
I’m seeing an ESS price discrepancy in VRM (Portugal zone), please check my reasoning, below is a the VRM graph showing a buy price of €0.0155 for the 8h timeframe:

and here’s my ESS config:

You see the formula i’ve configured:

((p+0.009)*(1+0.16))+0.001

Now looking at the ENTSOE API i see a value of €59/MWh:

This value is backed by the OMIE datasource:

Now, the value i was expecting for the 8h-9h timeframe was:

p = 59 / 1000 = 0.059 KW/h

>>> (((59/1000)+0.009)*(1.16))+0.001
0.07987999999999998

This feels like a classic “off-by-one” bug, what am i missing?

[lrascao (Luis Rascão)]

Here it is again on the 28th costing me money, it’s wrongly seeing the 8h-9h buy price timeframe as €0.0155 and decided to consume from grid instead of consuming from battery, the actual price is:

(((20.08/1000)+0.009)*(1.16))+0.001
0.034732799999999994

It’s very visible from the ENTSOE plot that the whole graph is shifted by one hour:

[Barbara (Barbara Jansink (Victron Energy))]

Hey, thank you for reporting this.

A member of the VRM team is looking into this!

[lrascao (Luis Rascão)]

Thanks, happy to help extracting whatever data is needed in the investigation, here is some fresh data from today:

VRM Energy Prices

ENTSOE

DESS Settings

Location settings in VRM

Cerbo GX Date/Time

[lrascao (Luis Rascão)]

Looked at few other visualizations i have available and they all match with VRM so most likely there isn’t a bug actually in VRM, the visualizations below all show a peak price from 7h-8h:

VRM:

My power provider (Coopernico):

And OMIE’s website:

What’s driving me crazy is how to interpret the datasets coming from ENTSOE, how can these not be UTC?

[Barbara (Barbara Jansink (Victron Energy))]

Thank you for coming back on that. I am unsure in which timerange the ENTSO-E prices are, but I assume CEST (so one hour different from Portugal) and that makes it look buggy.

Case closed then

[lrascao (Luis Rascão)]

yeah, that must be it
thanks again!