Measurement and Verification of Energy Savings.

M&V provides the proof that an energy savings plan works

The field of measurement and verification (M&V) of energy savings has matured in the last decade; we have learned that there is a big difference between measuring the flow of energy and predicting the reduction in energy savings based on metered data. For this reason, any discussion of monitoring energy savings must address both objective and subjective issues raised in the evaluation of an energy conservation measure (ECM). The recently revised and updated International Performance Measurement and Verification Protocol (IPMVP) provides good information and a method for verifying energy savings.

M&V has two components--cost and precision. Cost includes metering and the analysis required to measure savings. Precision is an issue for the calculations or metered values. Technological advances have reduced the cost of metering building energy systems. However, the complex nature of the performance of some systems requires more than just metering. For instance, the energy use of lighting systems often depends on building occupancy, and heating, ventilating, and air-conditioning (HVAC) systems can be load dominant or weather dependent. These factors, coupled with the day-to-day variation in operation and maintenance of energy systems makes the determination of energy savings difficult.

The need for accurate and cost-effective measurement and verification of energy savings is even greater at a time when energy-efficiency retrofits are increasingly seen as a way to improve building performance by enhancing indoor environmental quality and to reduce greenhouse gas emissions. Lighting levels, setpoint temperatures, and humidity levels not only affect the comfort and productivity of building occupants but also heavily influence energy consumption. Any evaluation of ECMs must include close monitoring …