In order to administer Power BI, there is a role in Office 365 that allows a user to be a Power BI administrator without having to have higher admin rights in Office 365. This role is called Power BI Service Administrator.
To assign the role, log into https://portal.office.com and log into the Admin portal.
Select Edit a User to edit an existing user:
Select the user and next to Roles select Edit:
To do this through PowerShell: https://powerbi.microsoft.com/en-us/blog/making-it-easier-to-administer-power-bi/