Hi guys, I started using DESS a week ago, so I’m still very much fresh to this, but in this time I had following issue happen twice.
Price forecast which DESS is showing me for tomorrow (20.06.2026) contains strange spikes. When price should be, according to market operator website, around zero all the way from let’s say 10:30 to 16:00, I get following prediction:
My Cerbo GX Mk2 is running v3.71 firmware, which I will try updating to v3.73 ASAP, but I’m not at the location for few days and am bit reluctant to trying do remotely - the place has flaky LTE internet connection at most times. Also FYI my price formula is Net price - 0.02 , so it is a bit offset against the reference.
So, does anyone else experience this or know why these spikes happen? Tomorrow is not the worst case scenario, with price around zero the loss from DESS thinking it’s selling at incorrect price will not be significant this time. But it bugs me knowing that this can happen and having to verify the price chart daily and having to switch DESS OFF and ON at appropriate times to avoid him taking action based on these errors is annoying.
Hi, this peaks are confirmed already by several people at this forum. Me also. I see it regularly at afternoon-evening for next day in case sell prices are negative (or very close to zero).
It is definitelly bug of VRM that is inserting vrong values for certain 15min intervals. Unfortunatelly this values are used for DESS decision planning for tomorrow. Fortunatelly values are corrected after midnight by VRM itself.
I cannot understand the mechanism how this can happend…
We tried to asked for correction, me at least @Barbara , but so far no reaction from Victron.
In the morning I noticed the prediction was Indeed already corrected. However the one from last week I still can see in the VRM if I select that date, so that one did not get corrected for me. Perhaps I switched DESS OFF even before midnight that day and by that I may have interfered with the correction, I do not remember. I’m guessing when it happens the positions and values of those peaks are somewhat random for everyone that gets this bugged prediction?
This is how tomorrow (21.06.2026) looks for me today, I will keep an eye on it, to see if it corrects itself overnight again.
as I wrote, the mechanism is not clear to me, it corelates with negative prices, but not 100%. See my prices from yesterday. The wrong calculation dissappeared for 30minutes before midday, but there is just one interval with exact zero at SPOT and the same afternoon, there are just negative SPOT prices, but one slot at VRM graph is correct.
You also does not have this wrong values at buy prices and I have at both prices. I assume that you don´t use SPOT price for buy. I am using SPOT also for buy prices.
Why the prices use different calculation before midnight and after midnight has to be investigated by Victron.
