326 Energy Project Financing: Resources and Strategies for Success
Option D may be used to assess the performance of all ECMs in
a facility, akin to Option C. However, different from Option C, multiple
runs of the simulation tool in Option D allow estimates of the savings
attributable to each ECM within a multiple ECM project.
Option D may also be used to assess just the performance of indi-
vidual systems within a facility, akin to Options A and B. In this case,
the system’s energy use must be isolated from that of the rest of the
facility by appropriate meters, as discussed in Chapter 3.4. 1. 1.
Option D is useful where:
- Baseyear energy data do not exist or are unavailable. Such situation
may arise for a new facility containing particular energy efficiency
measures needing to be assessed separately from the rest of the
facility. It may also arise in a centrally metered campus of facilities
where no individual facility meter exists in the baseyear period, but
where individual meters will be available after ECM installation. - Post-retrofit energy use data are unavailable or obscured by fac-
tors whose influence will be difficult to quantify. For example,
such situation may arise where it would be too difficult to assess
the impact of future facility usage changes that might significantly
affect energy use. Industrial process changes or uncontrolled
significant equipment additions often make the computation of
future significant baseline adjustments so imprecise that the error
in savings determination is excessive. - The expected energy savings are not large enough to be separated
from the facility’s utility meter using Option C. - It is desired to determine the savings associated with individual
ECMs but Options A or B isolation and measurements are too dif-
ficult or costly.
If the post-retrofit energy use is predicted by the simulation
software, the determined savings are actually maintained only if the
simulated operating methods are maintained. Periodic inspections
should be made of all equipment and operations in the facility after
ECM installation (see Chapter 3.4.1.3). These inspections will identify
changes from baseyear conditions and variances from modeled equip-