Every electric meter in Norway, Sweden and Denmark, and probably other countries as well, report used energy at intervals. In Norway it is each hour. I believe that is true in Sweden as well. And in Denmark, I understand it is each 15 minutes. Anyway, the problem is the reported energy used is sent from the electric meter after the interval is finished. And that means that every state change on the energy sensor is in the wrong hour or day for the norwegian electric meters. The sensor for the cost / price of electricity is usually changing a few seconds before the energy sensor changes, so we get the wrong price, too.
As you see, there is timing issues regarding state changes of price and energy when it happens at the hour. In the energy dashboard, it should be possible to configure some offsets to the entities so that energy is mapped to the correct price and the correct hour.
The energy dashboard doesn’t get anything right with this. The energy is stored in the wrong hour and mapped to the wrong price. This is a situation that is quite common and as the electricity meter is owned by the grid company, it is nothing we can do with it.
So just take your snapshot on the half hour, and then you know the number represents the prior hour’s stats and you can do the proper calculations. If you try to sync to the exact time, you will always have issues.
This is the best offset because it will always be right. You are not relying on the exact sync to the second. You are chasing a moving target.
