Thanks for a good dialogue. I am using it to implement charging control for my EV, where I use the Nordpool data to charge in the cheapest hours at night. I implement a control, which calculates the number of hours I need to charge, and turns on and off the charge box in the cheapest hours at night. This is possible because the charge box has an external port to control it, and I can read the amount of power needed directly from the car (Mercedes EQB integration into Home Assistant HACS).
I have just one addition to the dialogue: I do not believe it is entirely correct that you pay only 5,7 øre pr kWh when buying from Andel. I called their customer service, and got the figure 17 øre, which also corresponds to my own measurements. I have changed supplier to Vindstød, who charges less than 1 øre pr kWh, and announce this also on their web site. All ather suppliers (incl Andel) keep this number secret. With a consumption of 500+ kWh per month, it sums up to more than 1000 kr per year.