The Tariff Analysis Project (TAP) was originally developed to facilitate the analysis of electricity prices for the US Department of Energy's Appliance Efficiency Standards program. The tariff database and bill calculation applications have been used in particular for the Distribution Transformers and Commercial Unitary Air Conditioning Equipment rules.
The tariff analysis infrastructure consists of two primary components: a database containing the rate structure information and related data fields, and a web interface allowing users to enter, edit and view tariffs. Starting from these components, a variety of applications can be built, including bill calculator programs, batch data-processing scripts, and methods that allow TAP to interface directly with other software.
One of the key innovations in the development of TAP is the design of a data-table format that is flexible enough to accommodate the wide range of tariff structures encountered in practice. This general data-table can be thought of as a "universal tariff template". TAP currently accommodates the following rate design features for electricity tariffs:
In addition to the actual rates, understanding electricity pricing requires access to information about the variety of tariffs offered by a utility, including service types, customer classes, geographic constraints etc. This additional information is built into TAP, and allows the user of the database to sample the set of tariffs according to a wide variety of criteria.