A standardized tool for estimating energy savings
from billing data. An easy-to-use software package requiring only
readily available data.
The advanced version of PRISM (PRInceton Scorekeeping Method)
makes it easy to transform run-of-the-mill billing data into statistically
sound savings estimates. With PRISM, utilities and energy analysts
can systematically estimate total savings from a conservation or
demand-side management program, for large samples of houses or buildings
participating in the program, and for comparison groups as well.
Enhanced model tuning and data pruning in PRISM produce reliable
savings estimates and expanded statistical capabilities, from readily
PRISM, originally released in 1986, and available since 1995 as
a Windows-based easy -to-use software package, has been acquired
by some 500 organizations, and has become the standardized billing-analysis
evaluation method used by utilities, private firms, government agencies,
and universities. PRISM has a Windows-based user interface that
integrates major statistical functions with numerous user-friendly
features. For more information see Publications.
summary of method
PRISM is a statistical procedure that processes a year of monthly
billing data from a house or building to produce a weather-adjusted
Normalized Annual Consumption (NAC) index, along with other physically
meaningful parameters and extensive reliability statistics. A key
feature of the method is its estimation of best reference temperature
to which heating and cooling degree-days in the model are computed.
PRISM is generally run on the pre- and post-weatherization periods
for all buildings in a sample to produce distributions of savings
across the sample. With PRISM, participant and control groups are
easily compared, in graphical and tabular forms. The only required
data are readily available: 1)monthly billing data for the energy
being used (gas, oil, electricity), and 2) daily temperature data
published by the National Oceanic and Atmospheric Administration.;