@Dirk-Jan Faber @mvader (Victron Energy) Have you considered adding the hourly price stuff from DESS VRM to regular VRM for us that doesn't use DESS but only ESS and still would appreciate the cost analysis from DESS shown in our VRM portal for ESS usage?
My idea is that the savings should be relativly easy to do, price formula + grid code. When buying from grid the buy price is subtracted from total savings, when selling to grid the sell price as added to total savings, when self-consuming from PV or from battery the current buy price is added to total savings.
With a such implementation the user would quite easily see the savings done with ESS alone. The VRM display could also include a field that contains all the consumption (including extra batterycharge) with buy price multiplied with daily average cost* - that is my benchmark in my comparison to hourly prices, and how efficient I have been in moving consumption to low cost hours or self consumption.
With a VRM reporting as described above you could also theoretically recommend the customer on what would be the best cost saving performer, the customers current implementation of ESS or DESS.
* Here in Sweden, if you don't have either hourly pricing on the electricity from the grid or a fixed price then its the daily average price thats most common pricing model.