THE DOUBLE RATE TARIFF OF ELECTRICITY IN THE RESIDENTIAL SECTOR THE PORTUGUESE CASE
(1) FCTUC (2) INESC
Rua Antero de Quental, 199 3000 - 033 COIMBRA/Portugal
Telef. 351 39 83 26 89 Fax. 351 39 82 46 92
The paper presents the methodology used in a study to assess various options for reformulating the double rate tariff presently applied to electric energy in Portugal. The study has been conducted in order to evaluate the potential of this tariff option for a better use of system resources, with special concern on not derating the regional distribution utilities' revenues. Some of the present characteristics of this option are a relatively small ratio of prices between peak and off-peak periods and also the distinction between daily cycle and weekly cycle options. The methodology used has some limitations, namely because of the lack of information on price elasticity of demand that could help assessing the effects of price variations. Besides, although there is information on the customers' willingness to shift energy use from peak to off-peak, it is not easy to use it with great confidence. On the other hand, as the methodology is based on the use of average load curves of residential customers and end-use appliances as a background information, it allows the evaluation, through simulation, of the effects of varying the length of peak and off-peak periods. This, together with simulating price variations, allows dealing with uncertainty by means of scenarios.