Retrofit M&V - IPMVP Option B

Retrofit Measurement and Verification

Our typical measurement and verification services for energy retrofit projects are in line with option B (retrofit isolation) from the 2002 International Performance Measurement and Verification Protocol (IPMVP) Volume I, Concept and Options for determining energy and water savings. These services are intended for retrofits with performance factors (e.g., end-use capacity, demand, power) and operational factors (lighting operational hours, cooling ton-hours) that can be measured at the component or system level and where long-term performance needs to be verified. We utilize continuous metering of all energy quantities, or all parameters needed to calculate energy use, during the performance period. This approach provides the greatest accuracy in the calculation of savings.

Our services include physical assessment of equipment change-outs to ensure that the installation is to specification. The potential to generate savings is verified through observations, inspections, and continuous metering of energy or proven proxies of energy use, such as variable frequency drive speed for motor power. Baseline models are typically developed by correlating metered energy use with key independent variables.

Depending on the ECM, spot or short-term metering may be sufficient to characterize the baseline condition, or the continuous metering of one or more variables may occur after retrofit installation. We utilize spot or short-term measurements in the performance period to determine energy savings when variations in performance are not expected, and may support some normalized savings approaches though adjustments to the baseline and/or the performance period model(s). When variations are expected, we measure factors continuously during the contract period. Continuous monitoring of information is used to improve or optimize the operation of the equipment over time, thereby improving the performance of the retrofit. Performing continuous measurements or periodic measurements over the term of the contract will account for operating variations and will result in closer approximations of actual energy savings. Continuous measurements provide long-term persistence data on the energy use of the equipment or system.

Data collected for energy savings calculations are used to improve or optimize the operation of the equipment on a real-time basis, thereby improving the benefit of the retrofit. For constant-load retrofits, however, there are no inherent benefits of continuous over short-term measurements.