Introduction

The Bozeman Solar Project is a pilot project started as a collaboration between the City of Bozeman and NorthWestern Energy (NWE). Bozeman 'gave' NWE a bit of land (near where 19th crosses I-90) for the next 5 years, and in return NWE is building a 330 kW demonstration solar farm there. The solar project aims to examine the behavior of grid-tied solar generation and serve as a community outreach resource. Solar power presents unusual challenges to the utility due to it's variable nature, so NWE is interested in examining how these challenges can be mitigated to provide a robust grid with significant renewable-based generation.

One of the ways NWE hopes to address the challenges of solar is through active control of the solar plant. At the Bozeman Solar Project they hope to accomplish this by using smart inverters, all communicating with a Schweitzer Engineering Laboratories (SEL) Real Time Automation Controller (RTAC). The RTAC will serve as a communications and control hub for the solar plant by communicating with the inverters, a power meter, NWE's command and control system, and various other sensors installed at the plant. Our group's task is to configure the devices to achieve communication between them and explore the possibility of implementing active controls. SEL is generously donating an RTAC to MSU which we will use for testing the configuration scheme that we will eventually program into the RTAC at the solar plant.

Motivation

The primary motivation behind the project is public outreach. Solar power is very popular amongst consumers, yet has seen no previous application in NorthWestern Energy's grid. This project hopes to demonstrate the full capabilities of a solar plant and provide information to the public about where solar is successful or otherwise. NWE will be taking the data gathered by the RTAC and publishing it to the community on a real time basis on a webpage which customers can access and see for themselves the efficacy of the solar plant.

The secondary motivation behind this project is exploration of control options. The RTAC at the plant will provide lots of new control options to NWE that they haven't had experience with before, allowing them to experiment with different strategies to see which will integrate a varying generation resource most seamlessly into the grid.

Sponsor Information

Prof. Hashem Nehrir | MSU College of Engineering

Office: 626 Cobleigh Hall
Tel: (406) 994-4980
Email: hnehrir@montana.edu

Jonathan Shafer | NorthWestern Energy