Cogeneration Power Plant


The intent of the Cogen project was to reduce energy costs and increase the reliability of our electrical power supply. In addition to saving energy the hospital would save money and reduce our carbon footprint, increasing the reliability of the electrical power improves patient safety. During the majority of the year the Cogen plant can run completely independent of the electrical grid allowing EMMC to be a fully functional hospital even during times of power outages such as those caused by ice storms.

The cogeneration plant consists of a natural gas fired turbine generator and a Heat Reclaim Steam Generator (HRSG), which uses the turbine exhaust heat to make high pressure (100 psi) steam. The steam is used for hospital heat, humidification, sterilization, laundry, and cooking. In addition, an absorption chiller was installed in the central cooling system for the hospital. An absorption chiller uses steam instead of electricity to produce air conditioning. Excess steam produced by the turbine/HRSG in the summer months is utilized to feed this chiller. The steam produced by the turbine exhaust is basically a free byproduct that is the key to the overall savings of the Cogen plant.

The result is reduced steam cost by eliminating the need to run boilers, and deferred electrical cost by lowering our need to purchase electricity to produce air conditioning.

The cogeneration plant officially went online October 16, 2006 for an overall cost of $8,590,594. An award from the DOE/ORNL* of $3,000,000 reduced that total cost to EMMC to $5,590,594 as a government incentive to promote energy saving projects. Since that time the plant has provided 97 percent of the EMMC campus electricity and 95 percent of the steam required to operate. A utility tie-in to the local utility provides the balance of electricity and the original boiler plant provides the perfect balance of steam.
 
In 2010 EMMC was granted an Energy Star rating of 85 and awarded the 2010 ENERGY STAR CHP Award for reducing the fuel use by 27 percent for an equivalent amount of electricity and steam. The CO2 emissions were reduced by 10,600 tons/year.

In December of 2010 the Cogen plant had saved the entire cost of construction resulting in a 4.5 year payback.

*Department Of Energy / Oak Ridge National Lab

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