Document Type


Publication Date

Fall 2017


Timothy Anderson

Course Title

Operations Research

Course Number

ETM 540/640


Distributed generation of electric power -- Planning, Distributed generation of electric power -- Management, Operations research, Portland General Electric Company


The purpose of this study is to optimize a set of distributed energy resources (DERs) on an electric utility distribution level feeder. A DER is a decentralized resource, usually located at end-use electric utility customer sites, that stores or generates electricity – such as batteries and rooftop photovoltaic solar, or in the case of demand response, in which the utility has the ability to manage electricity consumption to the benefit of distribution grid operation. The aggregation and optimization of a set of DERs of disparate operating characteristics, over a period of three years is performed and the methods employed explained.

This aggregation of DERs is evaluated to determine if the required performance characteristics are present to meet specific distribution operation needs. In this case, the peak electricity demand experienced on the feeder exceeds its capacity to supply energy from the bulk electricity grid, and a portfolio of seven DER types is evaluated over the course of two peak winter and two peak summer days for a period of three years. The optimization model selects the lowest cost portfolio of DERs based on the fixed and variable costs of these resources, and their operating characteristics. If the portfolio is capable of meeting the load service requirements, utility planners may compare DER costs against alternative means of these requirements such as upgrading substation or distribution line equipment.

This study researched the methodology surrounding new planning methods such as distribution resources planning (DRP) form the perspectives of both public and private organizations to understand where the topic currently stands in terms of development, maturity, and need for additional research. The literature review sought to understand the perspectives of stakeholders as well as the supporting methodologies for construction of distribution and DER optimization models. One thing was clear - there were no definitive optimization plans for DERs, and many studies could only make recommendations based on limitations and assumptions outlined in models constructed for specific and often limited purposes.

The model presented here furthers the DER optimization research by creating a scalable model that selects a feasible portfolio of incremental DERs to meet a load growth on a hypothetical feeder while simultaneously minimizing the cost of the given portfolio. Our results show that there is a sound business case to be made in certain instances for a utility provider to implement incremental DERs to satisfy load growth as an alternative to proceeding with a traditional asset project such as a transformer or distribution circuit conductor replacement.

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