Sizing the Cogenerator

Abstract

By using the data gathered from the utility bills and the analyzing
of that data, a cogenerator can be selected that meets the optimum needs
of the facility. One of those optimum needs is not to overproduce either
electricity or thermal energy. The other need is to see that the economics
are suitable to the customer. Whatever altruistic benefits derive from
cogeneration, i.e. environmental and fuel conservation, customers will
not be attracted to spending their money unless it shows a fair return on
their investment.
The computer is a valuable tool in making this selection. Variables
in energy production and hourly operation are easily handled by a com-
puter with the results readily viewable. The following analysis is from
a project where the client’s actual electrical and gas usage as well as the
cogenerator’s specifications have been entered to present a complete
picture.
Table 1 shows that this customer has consumed 199,264 therms
during the year, which cost $122,152; Table 2 shows 4,390,560 kilowatts
used at a cost of $307,339 for the energy; and Table 3 shows a demand
usage of 10,284 kW, which cost $102,840.
Table 4 depicts how this gathered information is put into the com-
puter and is analyzed.