How would you like to save 6.2 million kWh annually while using a renewable fuel source? Take a cue from the Eastern Illinois University (EIU) and its Renewable Energy Center. In operation since 2011, this biomass facility has reduced energy use by 50% and carbon emissions by 80% over the old coal-fired plant. The plant is expected to generate $140 million dollars in savings over the next 20 years.
When the original 1928 power facility was at the end of its life, the university took the opportunity to find a more sustainable replacement. Partnering with Honeywell International, an $80 million performance contract secured the necessary funds for the new plant. By rerouting the savings from other campus-wide efficiency projects, this funding option ensured that neither students nor taxpayers would bear the costs.
With a price tag around $55 million, Eastern’s Renewable Energy Center houses four boilers. Two burn biomass, such as wood chips and switchgrass, and the others use natural gas with a fuel oil backup. EIU’s campus energy needs can be met by running any two of the four boilers.
The system uses gasification technology, which is a two-stage combustion process. Fuel is first heated to a high temperature in a low-oxygen environment, which creates synthetic natural gas. The gas is then captured and combined with additional oxygen to combust just like natural gas. This is a much cleaner burning process compared to coal burning, with only about 5% efficiency lost compared to the traditional natural gas process.
The plant is also designed for fuel flexibility through its gasifiers. With a traditional combustion boiler, the fuel sources must generally be the same in moisture, size and density. Because it isn’t a direct combustion facility, these gasifiers can accept more variations in the fuel source.
A unique feature is that one of the biomass boilers, a high-pressure unit, feeds into a back-pressure steam turbine to generate electricity as a byproduct. By doing this, the university gets its electricity in the neighborhood of 2 cents per kilowatt-hour as opposed to the university rate of 7 cents or the traditional utility rate of 11 cents.
The Renewable Energy Center is the first solid fuel power plant registered with USGBC and earned LEED Platinum for New Construction.