M&V (Measurement & Verification) is a procedure for quantifying and documenting the energy savings from a measure. Savings cannot be measured directly; they are calculated as the difference between the expected consumption in the baseline state and the actual consumption after the measure.
IPMVP and Options A to D
The generally accepted framework is the IPMVP (International Performance Measurement and Verification Protocol). It distinguishes four options: A and B monitor only the equipment or system where the measure was implemented (A measures key parameters, B measures all of them), C monitors the whole plant using the main meters, and D uses calibrated simulation. The principles of measuring and verifying the energy performance of organisations are summarised in the ISO 50015 standard.
Example from manufacturing
A plant replaces its lighting with LED and wants to know how much it has saved. The baseline (EnB) is adjusted to current production and weather, and the actual consumption is subtracted from it. For measures affecting the whole plant, Option C is suitable; for an isolated piece of equipment, A or B. The difference is the verified saving, which can be converted into money.
Why it matters
Without M&V, savings remain mere estimates from design documentation and in practice often differ. Documented savings support further investment and are an important basis for the audit and for ISO 50001. Tracking the cumulative deviation (CUSUM) shows whether the savings are being sustained.
Frequently asked questions
Can savings be measured directly?
No. Savings are what you did not consume, and that cannot be measured. They are calculated as the difference between the expected consumption in the baseline state (adjusted to current conditions) and the actual consumption.
Which IPMVP option should I choose?
It depends on the measure and on the metering. For measures on a single piece of equipment, A or B is suitable; for measures affecting the whole plant, C. The choice is guided by what can be measured reliably.