According to the ERSE, the liberalised electricity market regulator, EDP's market share, in terms of customers and volume, dropped.
The market share of EDP Comercial, a unit of Energias de Portugal that is the leading supplier in Portugal’s free market for electricity, shrank by 0.3 percentage points in December in terms of the number of customers and by 0.1 in volume, according to the regulator.
According to the newsletter on the liberalised electricity market published by the ERSE, the company had 80.8% of the market in terms of customers, down from 83.8% in January. In terms of consumption, it slipped to 41.8% from 42.3%.
By contrast, Endesa and Iberdrola saw their market shares by number of customers swell by 0.1 and 0.2 percentage points respectively in December, to 5.7% and 4.9%.
The two Spanish-owned supplies, which are second and fourth in the market in customer numbers, have been increasing their market shares for more than a year.
Galp, the third-largest supplier in the free market in terms of customer numbers, ended 2018 with a market share of 5.1%, down from 5.3% a year earlier.
In December, the free market encompassed some 5.1 million customers, up around 11,500 or 0.2% from November. From December 2017, the figure was up 2.7%.
Annualised consumption in the free market in December was 43,076 GWh, up 2.9% on a year earlier.