A Cogeneration Case Study Using the Interactive Energy Balance Program

Abstract

Cogeneration is a highly effective means of increasing energy ef-ficiency and reducing energy costs by utilizing the heat that wouldnormally be wasted and use some or all of it for the thermal require-ments of a facility. This effective utilization of heat generated duringelectricity production allows for an increase of fuel efficiency from35% to almost 85%. Cogeneration not only reduces energy costs andincreases energy efficiency, but is also beneficial to the environment byreducing the amount of pollutants that are emitted into the atmo-sphere.In a previous work we presented and described the new Interac-tive Energy Balance (IEB) software. The package offers an easy way toaccount for energy bills, working equipment and their energy operat-ing characteristics. Among the equipment considered are: lighting, airconditioning, refrigeration compressors, air compressors, motors, andothers. The electric energy consumed by all pieces of equipment isbalanced against the energy bills (last 12 months). The correspondingenergy costs, graphs, pie-charts, and free format reports are automati-cally generated showing paths and trends on energy consumption. A“Recommendations” section allows for a quick, but beyond a back ofthe envelop type of calculation, initial analysis of potential energy im-provement projects associated with current equipment, and/or for theinstallation of new ones.As a result of the increasing interest, we have included in IEB’s“recommendations” section a “cogeneration” option. Among its manyfeatures is a typical cogeneration environment window with fuel load, power generated, thermal load output, and efficiency, allowing for avariety of uses for the exhaust heat. Furthermore, an information veri-fication chart is displayed and a final “cogeneration savings” printablesummary chart is shown. This chart includes (among others) theworth of thermal load, worth of cogeneration, fuel cost, operatingcost, total savings, simple payback, and return on investment. In thiswork we briefly describe IEB and present a case study on a cogenera-tion recommendation. This provides insight on the versatility, fasterdata entry, balancing process, graphical display, recommendations andmany other features of the software. In addition, we further demon-strate the value of the energy balance approach, and the many optionsfor cogeneration and other energy savings projects