If you need to change the power of light that have contracted know that:
According to the RD 1955/2000, the consumer may request power down only 1 time per year.
Installation must comply with current regulations. This is,you should have ICP (Interruptor de Control de Potencia), and meet the technical standards and safety regulations.
If the installation has more than 20 years, the distribution company may request a review and the relevant certificates.
The change in power has a cost that will feed into the customer's bill. Since February 2014, the cost of modification is € 9.044. If one were to review a facility for having a history of more than 20 years, the cost is € 8.01.