According to the Andalucian Energy Agency, households in the region save around €17 million as a result of the clocks going back one hour in winter. The clocks go back at 03:00 on Sunday morning.
The time change is generally viewed as a positive measure although it does have some temporary side effects, such as affecting the human biological clock. The change can cause temporary sleep disorders, especially in children and the elderly, but these tend to only last for two or three days.
The Agency also notes that people could save even more energy by, for example, turning off the standby function on computers and tv’s which apparently accounts for about 6% of household energy consumption. This would save on average about €40 per year.