I can do right click on the Taskbar, select 'properties' and then select "left" for the "Taskbar location on screen" under "Taskbar".
However the label next to the icon (e.g. the name of an open Word document) is only up to three letters, whereas I get at least 16 characters if the toolbar is displayed at the top/bottom.
The solution would be, to make the sidebar wider, but there seems to be no option for that.
FYI, I am using the sidebar to save vertical screen real estate. It's 2018, all screens are wide, but all software incl. all browsers crams all their info, tabs, bookmarks or ribbons into the precious vertical screen estate. Google Chrome briefly had an experimental feature for side tabs, but then canceled the project.