5.Measurement Methods for EPIs

The data is collected either through energy bills or through specialized measurements. Energy bills provide data for long periods of time (month at least) and indeed these data are aggregated, so no conclusions can be drawn about the variance of the EPIs. On the contrary, a measurement programme can provide the required information on the variability of EPIs and on all the factors affecting them.  The data collected should be accurate in terms of: (i) measurement, (ii) frequency and (iii) quality. Measurements are usually collected through sensors, which ensure repeatability and reliability, and measurements should be collected in relation to the same period, i.e. daily, hourly or monthly, etc.