The Transmission Operating and Maintenance Expense Survey is an HGP registered trade-marked database covering the key performance parameters for the commercial wholesale transmission grids in the United States that are part of NERC.

Each of the nuclear power plant operation cost has been assigned to one of seven peer groups based on objective characteristics (such as the commercial operating date, size in MWe and NSSS type).

Additional or custom peer groups can be developed for performance issues such as steam generators or regulatory performance.

HGP updates the database of transmission plant operation cost on an ongoing basis, and provides its active clients access to the database.