When Do I Use PowerPivot for SharePoint?
After you have created PowerPivot workbooks by using your desktop Excel application, you’ll probably want to:
Share them with other users in a secure and reliable way
Refresh them periodically and automatically
Make sure that all the workbook’s users see its most current version
Turn your workbook into a web-based BI application, viewing and interacting with it in the browser
Empower the IT professionals with tools to assist with the management of the PowerPivot workbooks
PowerPivot for SharePoint is designed to meet the requirements of all the preceding scenarios, giving you a way to share, refresh, and update workbooks in a secure way that adheres to IT security policies while enabling users to interact with the content of the workbooks from their browsers.