On the Electricity Rates page, and any other input page in SAM that uses a table to enter data, if you use Ctrl-C and Ctrl-V to copy and paste data into the table, the data disappears when you leave the page. This is a problem with SAM 2016.3.14 Revision 1 that we will fix.
As a workaround, after you paste the data into the table, click the table's Copy button and then the Paste button. That will cause the values you just pasted to "stick" so that they won't disappear when you leave the page.
Best regards,
Paul.