A Cogeneration Case Study Using the Interactive Energy Balance Program

ABSTRACT

Cogeneration is a highly effective means of increasing energy efficiency and reducing energy costs by utilizing the heat that would normally be wasted and use some or all of it for the thermal requirements of a facility. This effective utilization of heat generated during electricity production allows for an increase of fuel efficiency from 35% to almost 85%. Cogeneration not only reduces energy costs and increases energy efficiency, but is also beneficial to the environment by reducing the amount of pollutants that are emitted into the atmosphere.

In a previous work we presented and described the new Interactive Energy Balance (IEB) software. The package offers an easy way to account for energy bills, working equipment and their energy operating characteristics. Among the equipment considered are: lighting, air conditioning, refrigeration compressors, air compressors, motors, and others. The electric energy consumed by all pieces of equipment is balanced against the energy bills (last 12 months). The corresponding energy costs, graphs, pie-charts, and free format reports are automatically generated showing paths and trends on energy consumption. A “Recommendations” section allows for a quick, but beyond a back of the envelop type of calculation, initial analysis of potential energy improvement projects associated with current equipment, and/or for the installation of new ones. As a result of the increasing interest, we have included in IEB's “recommendations” section a “cogeneration” option. Among its many features is a typical cogeneration environment window with fuel load, power generated, thermal load output, and efficiency, allowing for a variety of uses for the exhaust heat. Furthermore, an information verification chart is displayed and a final “cogeneration savings” printable summary chart is shown. This chart includes (among others) the worth of thermal load, worth of cogeneration, fuel cost, operating cost, total savings, simple payback, and return on investment. In this work we briefly describe IEB and present a case study on a cogeneration recommendation. This provides insight on the versatility, faster data entry, balancing process, graphical display, recommendations and many other features of the software. In addition, we further demonstrate the value of the energy balance approach, and the many options for cogeneration and other energy savings projects.