Evaluation of the effects of a tariff change on the Italian residential customers subject to a mandatory time-of-use tariff

Panel: 7. Monitoring and evaluation

This is a peer-reviewed paper.

Authors:
Simone Maggiore, R.S.E. (Ricerca sul Sistema Energetico) S.p.A., Italy
Massimo Gallanti, R.S.E. (Ricerca sul Sistema Energetico), Italy
Walter Grattieri, R.S.E. (Ricerca sul Sistema Energetico), Italy
Michele Benini, R.S.E. (Ricerca sul Sistema Energetico), Italy

Abstract

Time-of-use (ToU) tariff at two-part rate periods has become the default condition for residential customers in Italy since July 2010. It provides for variable prices of electricity depending on the hour of the day: the price is higher during “peak hours” (the hours between 8 am and 7 pm on working days) and lower during “off-peak hours” (all remaining hours); the price difference between the two groups of hours was fixed and equal to 10% during the transitional phase (July 2010-December 2011), while, starting from January 2012, the final ToU tariff has come into force with a larger price difference deriving from the electricity market hourly price profiles.

In order to evaluate the effects of the switch from the transitional to the final ToU tariff, RSE selected and analyzed a group of 1,000 customers, statistically representative of the whole Italian population. Their electricity consumption data have been measured by smart meters every 15 minutes and have been made available by the corresponding DSOs, starting from January 2011.

Moreover, the customers are subject to a set of periodic computer assisted interviews, aimed at gathering information about the electric appliances each family owns and about their usage on the different days of the week and at different times of the day.

The paper will present the results of the evaluation of the effects of the switch from the transitional to the final ToU tariff, taking into account in particular the shift of the loads from peak to off-peak hours.

The paper will also describe the statistical model, built upon the information gathered by the interviews, which RSE implemented with a specific software tool based on Monte Carlo simulation; such model has been used to assess both the contribution of each appliance to the overall load curve and the effects of moving its usage to different periods of the day.

The consequent benefits are analysed both from the final user’s point of view and from the whole Italian system’s one.