End-Use Data Development for Power System Load Model in New England - Methodology and Results

End-Use Data Development for Power System Load Model in New England is a project sponsored by the U.S. Department of Energy with a goal of providing a representation of electrical loads to facilitate power system dynamic stability modelling.

NERC Reliability Standard TPL-001-4 calls for the study of dynamic load performance per requirement R2.4 and associated sub-requirements. The work performed in this project resulted in a representation of electrical system load in New England by 1) summer peak and spring light load hour 1, 2) by seven geographic regions within New England, 3) by customer sector, 4) by electrical end-use categories specific to each customer sector, and 5) by load components identified as being inputs to dynamic stability modelling applications.

The load representation developed in the project is in the framework of the Western Electricity Coordinating Council (WECC) composite load model which divides system load into fractional components accounting for the constant power lo

ads (electronics and various motor applications), constant current loads, and constant impedance loads. The estimated load representation produced in this project was developed using a "bottom-up" methodology which leverages the Energy Information Administration's residential, commercial buildings, and manufacturing energy consumption surveys as core data sources. DNV GL augmented this data with end-use consumption estimates from secondary sources. The end-use consumption estimates were calibrated to specific population metrics and weather data for the seven New England regions. The methodology first derived annual electricity consumption estimates by end-use category within sector and region and then adjusted the annual consumption to the load in the summer peak and light spring load hours using the DNVGL load shape library.

The ultimate representation of system load into the WECC composite load model component categories used rules of association for the proportional breakdown of load by end-use category (e.g. incandescent lighting) and sector class (e.g. lodging within the commercial sector). Some rules of association assign 100% of the end-use load for the sector class to a single load component (e.g. single-phase space cooling compressors are assigned to the 'Motor D' load component) while others decompose the end-use load to multiple components.

An important goal for the project was to not only develop the New England regional load decompositions but also to rigorously document the analysis approach and assess data gaps and the various data sources used in the analysis with respect to its application in this project, acknowledging that the data may have been originally collected for very different purposes. The rules of association were developed primarily from engineering judgment of the DNV GL and stakeholder project team rather than grounded on evaluation data (as we would vastly prefer), building on the foundation of the rules of association developed for the WECC composite load model.