This question comes up quite often. What permissions does a user need to execute a command in the SharePoint 2010 Shell?
Short answer is you will need http://itstimetogetorganized.com/plan-ahead-for-your-summer-vacation?share=twitter SharePoint_Shell_Access access.
To give user http://sktpharma.com/the-do-s-and-don-ts-of-mmj-card-25/ SharePoint_Shell_Access access run the following command
Add-SPShellAdmin -UserName [USERNAME] -Database [DBNAME]
-Database switch is optional and if the database is not specified the configuration database is used.