Review of Methods for Measuring and Verifying Savings from Energy Conservation Retrofits to Existing Buildings

Abstract

The Measurement & Verification (M&V) process has evolved in the last 15 years to provide a high confidence approach for determining the resulting savings from a variety of retrofits and energy efficiency enhancements. M&V has a dual role. First, it quantifies the savings being obtained. Since the persistence of savings has been shown to decrease with time,1 long-term M&V provides data to make these savings sustainable. Second, M&V must be cost effective so that the cost of measurement and the analysis does not consume the savings.2, 3 Currently, a goal of about 5% of the savings per year has evolved as a preferred criteria for costing M&V, since the cost justification directly results from the savings obtained. The general procedure involves a selection of using a monthly billing analysis, a daily or hourly procedure, a component isolation analysis, or a calibrated simulation. Calibrated simulations are usually expensive and difficult to complete.