Postgres data can be used in Excel 2016, but this requires an ODBC driver and external configuration of the database server. As far as I can tell, Npgsql drivers do not work with my version of Excel, which is a 32-bit version of MSO 326 bit aka "Home Premium".
The Postgres ODBC driver is available here: https://www.postgresql.org/ftp/odbc/versions/msi/ Download and install the latest version. It must be installed without rebooting the system.
Configuring DSN (I used the machine) using the ODBC data source configuration application (XX-bit). The driver version must match your version of Excel.
Excel 2016 "Data → New Query → From Other Sources → From ODBC", . , , , Excel.