Combined Heat and Power - Ripley Heat Plant

Energy Optimization/Ripley Combined Heat and Power Renewable Energy Project

This project has four goals pertaining to campus facilities operations: 1) reduce operating costs, 2) provide fuel flexibility, 3) utilize a renewable resource, and 4) create local jobs. To meet these goals, the university worked with a major energy service company to conduct a comprehensive energy optimization analysis of the campus and identify improvement measures.

The existing central steam plant that serves a majority of the campus facilities was a primary focus, specifically concerning the type of fuel utilized. The primary fuel for the existing plant is natural gas, with fuel oil as backup. The Heating Plant is also the primary distribution point for electricity purchased from the Marquette Board of Light & Power (MBLP), a municipal generating station. Backup electrical power consists of emergency levels of individual diesel/natural gas generators in a minimum number of the University’s major facilities.

As part of a campus energy optimization project, a new biomass fueled cogeneration combined heat and power (CHP) plant is under construction as an addition to the existing plant that will provide guaranteed cost savings. The new plant addition will utilize a solid fuel stoker boiler rated at 40,000 pounds per hour, capable of burning wood chips with natural gas as a backup fuel. The new plant will be capable of meeting 87% of thermal needs on campus. A back pressure steam turbine generator will produce up to 645 kilowatts of electricity, which is about 16% of the university's electrical load. The existing natural gas boilers will supplement the biomass plant for peaking duty and electricity will continue to be purchased, as needed, from the Marquette Board of Light and Power.

The biomass unit will utilize wood chips and wood by-products of the Upper Peninsula such as tree tops, sawdust, and bark for fuel. Discussion of the costs of wood by-products and availability on a continuous basis confirmed the viability of this renewable resource as a reliable fuel source for the project. The new plant will incorporate the best available boiler control technology and meet the Environmental Protection Agency and Michigan Department of Natural Resources and Environment Standards.

The project also will address several long term maintenance issues in the existing plant, including the installation of a fire suppression system throughout the existing facility, and the replacement of the original water softeners and brine system.  Other energy optimization improvements include the interconnection of the New Science chiller to the Learning Resource Center chilled water system and the replacement of the existing single-stage unit in Cohodas Hall with a two-stage absorption chiller.  

NMU Project Manager: Gisele Duehring

Architect/Engineer: Johnson Controls, Inc.

Project Budget: $16.4 million

Project Period: April 2012 - June 2013