1. 1
Trondheim, May, 27th
- 28th
2013
Evaluation of the effects of a tariff change
on the Italian residential customers
subject to a mandatory Time-of-Use tariff
Simone Maggiore, Michele Benini, Massimo Gallanti, Walter Grattieri

2. 2
Trondheim, May, 27th
- 28th
2013
Evaluation of the effects of a tariff
change on the Italian residential
customers subject to a mandatory
Time-of-Use tariff
Simone Maggiore, Michele Benini, Massimo Gallanti, Walter
Grattieri

3. 3
Summary
- Background;
- ToU tariff experience in Italy
- Effect of the tariff change on the load curves;
- Effect of the tariff change on the consumption
habits;
- Results of the simulation with the software
tool SCUDO7;
- Conclusions

4. 4
Background
July, 1st
2010: Time of Use rates start becoming mandatory for
all “Default Service” residential customers (≈ 25
M customers involved)
ToU Rates: Peak hours (8.00-19.00 working days)
Off-peak hours (remaining hours)
Motivation: make the tariff more cost reflective and
progressive expose consumers to time variable
costs of electricity supply
Transition period: up to December, 31st
2011 limited variation
between peak and off-peak price
Regular period:from January, 1st
2012 larger variation between
Liberalisation of the electric system completed in 2007:
-Production and Sale of electricity are “free”;
-Transmission and Distribution services are regulated;
-Customers can either choose their retailer on the energy market,
or be supplied by the local distribution company at a regulated
rate (“Default Service”)

5. 5
Tou rate (transition period)
0
5
10
15
20
25
30
35
1,500 kWh/yr
Peak
[c€/kWh]
Energy Fixed Charge System Charge Taxes
2,500 kWh/yr 3,500 kWh/yr
Off-Peak Peak Off-Peak Peak Off-Peak
= 7.2Δ
%
= 4.7Δ
%
= 3.4Δ
%
= 10.0Δ
%

6. 6
Main activities
Analysis of monthly consumption for a “Customer
panel” composed of nearly 1,000 families:
• Statistically representatives of the whole Italian
population;
• Time series starts in July 2011.
Scope
To investigate if and how much a time variable
electricity price can significantly affect consumers’
behaviour and change level and profile of consumption
Research project

7. 7
Geographical distribution

8. 8
Effect of the tariff change on the load curves
(1/8)

9. 9
Effect of the tariff change on the load curves
(2/8)

10. 10
Effect of the tariff change on the load curves
(3/8)

11. 11
Winter 2012 –
Winter 2011
Spring 2012 –
Spring 2011
Summer 2012
–
Summer 2011
Δpeak
hours
Δoff-
peak
hours
Δpeak
hours
Δoff-
peak
hours
Δpeak
hours
Δoff-
peak
hours
0,39%
-
0,39%
0,50%
-
0,50%
-
0,56%
0,56%
Average energy shift from peak to off-peak hours
average working day
Effect of the tariff change on the load curves
(4/8)

12. 12
Effect of the tariff change on the load curves
(5/8)

13. 13
Effect of the tariff change on the load curves
(6/8)

14. 14
Effect of the tariff change on the load curves
(7/8)

15. 15
Effect of the tariff change on the load curves
(8/8)

16. 16
PEAK
HOURS
OFF-PEAK
HOURS
Transitional ToU tariff
(2011)
30,95% 69,05%
Final ToU tariff (2012) 31,53% 68,47%
Δ 0,58% -0,58%
Effect of the tariff change on the consumption
habits (1/3)
WASHING MACHINE
PEAK
HOURS
OFF-PEAK
HOURS
Transitional ToU tariff
(2011)
18,94% 81,06%
Final ToU tariff (2012) 19,65% 80,35%
Δ 0,71% -0,71%
DISHWASHER

17. 17
PEAK
HOURS
OFF-PEAK
HOURS
Transitional ToU tariff
(2011)
32,22% 67,68%
Final ToU tariff (2012) 33,02% 66,98%
Δ 0,80% -0,80%
Effect of the tariff change on the consumption
habits (2/3)
ELECTRIC OVEN
PEAK
HOURS
OFF-PEAK
HOURS
Transitional ToU tariff
(2011)
28,47% 71,53%
Final ToU tariff (2012) 26,72% 73,28%
Δ -1,76% 1,76%
TUMBLE DRYER

18. 18
PEAK
HOURS
OFF-PEAK
HOURS
Transitional ToU tariff
(2011)
21,28% 78,72%
Final ToU tariff (2012) 22,60% 77,40%
Δ -1,32% 1,32%
Effect of the tariff change on the consumption
habits (3/3)
WATER HEATER
PEAK
HOURS
OFF-PEAK
HOURS
Transitional ToU tariff
(2011)
22,68% 77,32%
Final ToU tariff (2012) 22,56% 77,44%
Δ -0,12% 0,12%
AIR-CONDITIONER

19. 19
Results of the simulation with the software tool
SCUDO7 (1/3)

20. 20
Results of the simulation with the software tool
SCUDO7 (2/3)

21. 21
Increase the probability of use during off-peak hours of the following appliances:
-washing machine
-dishwasher
-iron
-water heater
-vacuum cleaner
Results of the simulation with the software tool
SCUDO7 (3/3)

22. 22
• Load curves are every similar before and after the tariff
change, both in their shapes and in their average values.
• Consumers’ habits have not been affected by the tariff
change, as the consumption shift from peak to off-peak hours
has been low.
• The theoretical consumption shift which might be necessary to
achieve a benefit larger than 1 €/year has resulted to be
around 20%, which does not represent an unfeasible
possibility for the average domestic user.
• But there are some factors which might prevent such shift to
occur, such as the reduction of the price difference between
peak and off-peak hours which is currently taking place in
Italy.
• Some possible solution are changing the composition of the
current groups of hours, the introduction of the “Critical peak
pricing” or using other benefit different from the mere monetary
Conclusions

23. 23
simone.maggiore@rse-web.it