Three districts concentrate 58.5% of all energy supplier changes in Portugal. Lisbon accounts for 30.97% of sign-ups, Porto 18.24% and Setúbal 9.30%. These are followed by Aveiro, Braga and Leiria, each with values between 5% and 7%. This distribution contrasts with the housing credit market, where concentration on the coast is explained by higher property prices and higher incomes in the region.
Changing energy supplier in Portugal requires no credit approval, does not depend on income, has no cost and does not interrupt supply. Theoretically, it is a decision accessible to any family. The ComparaJá analysis concludes that geographic concentration does not result from financial barriers, but from exposure to information. The decision to compare tariffs depends on knowing that prices vary between suppliers, on being aware of the right to change, and on finding where to make the comparison — conditions that are distributed unevenly across the territory.
The cost of this asymmetry is quantifiable. For a family with two children, consuming 400 kilowatt-hours per month and with a power capacity of 6.9 kVA, the difference between the cheapest and most expensive tariff was 25.45 euros per month. For a large family with 908 kilowatt-hours and 13.8 kVA, the gap reached 58.53 euros per month. These values do not depend on the region, but capturing them depends on the family knowing they exist.
When consumers do switch, they almost always do so partially. Seventy-four percent of changes involved only electricity, and almost 95% chose the simple tariff with a single price throughout the day. This behavior reflects decisions on the most visible component of the bill, without optimizations that require knowing one's own consumption profile. The conclusion is that a district with little representation in supplier changes is not a district where switching is not worth it, but a district where the available savings continue to go unclaimed.
