376 Energy Project Financing: Resources and Strategies for Success
Baseyear Energy Use
The following steps were followed to compute baseyear energy
use after the first post-retrofit year:
1 The newly installed meters were calibrated before installation. Op-
erating staff read the meters monthly and recorded monthly total
steam and electricity use, as well as monthly demand, for each of
12 months throughout the post-retrofit year.
2 A model was developed of the building with the ECM’s installed.
This model used actual weather of the post-retrofit period and
the operating profiles recorded in the same period. The modeled
space temperatures and humidities were examined to ensure they
reasonably matched the typical range of indoor conditions during
occupied and unoccupied days. Initially the model did not model
energy use well, so farther site investigations were undertaken.
During these investigations it was found that during unoccupied
night periods, there was no effective indoor temperature change,
so the thermal mass characteristics of the model were adjusted.
With this correction the model was determined to adequately
match the calibration data. The modeled results compared to the
monthly data as follows
MBE CV (RMSE)
Electricity Consumption 8% 10%
Electric Demand 12% 15%
Steam 5% 8%
3 This accuracy of calibration is good enough to allow reasonable
confidence in the relative results of two runs if the model. How-
ever the model should not be used to compare simulated results
to actual data.
4 The calibrated model was archived, with both printed and elec-
tronic copy of input data, diagnostic reports and output data.
5 The calibrated model was then adjusted to remove the ECMs, and
the weather data file was changed to correspond to the actual