Currently the National Technical Information Service Bibliographic Database includes records on over 2.8 million scientific and technical reports arranged by major subject categories. The NTIS  has now made available RSS Feeds by Subject Category: Follow the RSS Feeds link at ntis.gov to get started. Energy is one of the categories, for example.

“NTIS values its recognition by the technical information community, libraries, and participating Federal Government agencies as the leader in providing must-have U.S. Government technical content. To this end, NTIS will always strive to acquire, index, abstract, and archive the largest collection of Government-sponsored technical reports in existence.”

The October 2008 issue of the NTIS Technical Reports Newsletter is now available online from http://www.ntis.gov/pdf/ntrnews4.pdf.  To subscribe to the free Newsletter, just send an email with your name and email address to ntrnews@ntis.gov.

Source, the October NTIS Technical Reports Newsletter