Thanks, Ivy, for the links!

For everyone else:
Ivy Glasgow's first link (https://forcechange.com/64616/dont-restrict-standards-for-energy-saving-...) has language for a petition letter (about half way down the page) that you can copy and modify as you like to send to your senators.
You can find the contact information for your senators, including both phone numbers and links to their "contact" websites here:
http://www.senate.gov/general/contact_information/senators_cfm.cfm