The DESS discharge strategy is frequently postponed to the next day because the prices are 1 or 2 cents higher.
This will create an avoidable loss. Let me explain.
My battery is 18kwh with 50% backup power reservation. So to charge and discharge for Dess profit only 9kwh is left.
If like today the discharge planned at 17.00 was €0,27 per kwh and tomorrow at 08.00 the price is €0,29 per kwh the discharging is postponed.
To keep the battery above minimum charge there is an extra loss of (in my case) around 0,2kwh per hour because of peak shaving is taking place only above minimum charge.
To keep battery for this 15 hours above minimum charge because of the postponement an extra 15 hrs x0,2 kwh = 3 kwh is lost. The prices in this period are between 21 and 25 cent so an average of 23 cent x 3 kwh= € 0.69 extra cost for gaining 9x2= 18 cent!
That’s a loss of € 0,51
So it’s better to discharge at 0,27 and do nothing the next day.