Memory allocation failure on dataset refresh

I have exactly the same problem. I have read all the suggestions on forum posts I have found but the suggested solutions were general everywhere and did not help finding the column or query step that I needed to delete.

For a beginning, it would be also useful to see whether it is in power query or in power bi that the memory consumption goes high. I have steps in power query that could potentially be memory-intensive (such as merges) and also calculated columns and tables in power bi.

If I do a refresh on power bi desktop and monitor memory usage in the task manager, I can see that memory usage is the highest right before the end of the refresh. Memory usage usually goes above 15 GB, which means that it could not fit the 10 GB that is allocated for shared capacity subscribtions in Power BI Service. It is weird because the size of the dataset that I am trying to refresh is 39 MB. 

I have tried to set up incremental refresh as well, but the first refresh that was supposed to create the partitions failed as well.