How to Do Energy Model Uncertainty Analysis with Correlated Input Variables

Energy modelers are starting to try to quantify the uncertainty in their energy models. The methods for estimating uncertainty when inputs are independent are fairly well known. However, in the case of buildings, many inputs are not independent.  In particular, occupant related loads such as plug loads, lighting loads, and occupant heat loads are known to be well correlated. Uncertainties of correlated variables can be propagated if joint probability distributions are used and the joint distributions are properly sampled.  In this paper, the selection and sampling of joint distributions for uncertainty with correlated inputs is discussed.