Portugal Wastes 96 Percent of Domestic Cooking Oil That Could Replace Fossil Fuels — Zero Calls for Urgent Action

Portugal is collecting less than four per cent of the used cooking oil generated by households — squandering a resource that could produce 25 to 30 million litres of biofuel per year and help cut the country's dependence on imported fossil fuels. The warning comes from Zero, Portugal's leading environmental association, in a report published this week that calls the waste "a serious failure of public policy."

The numbers behind the waste

Data obtained by Zero from the Portuguese Environment Agency (APA) shows that Portugal generates between 43,000 and 65,000 tonnes of used cooking oil (OAU) annually, of which roughly 62 per cent — between 27,000 and 40,000 tonnes — comes from domestic kitchens. Yet in 2023, municipalities reported collecting just 908 tonnes. The year before, the figure was even lower at 868 tonnes.

That means municipal collection covers barely 2.3 to 3.4 per cent of the estimated domestic potential. The rest is either poured down drains — causing damage to sewage and wastewater treatment systems — or simply thrown away.

Infrastructure gap is the bottleneck

Zero's analysis of Portugal's 24 largest municipalities — those with more than 100,000 inhabitants, representing nearly half the national population — found that they collected a combined 515 tonnes of used cooking oil in 2022, averaging just 0.11 litres per resident per year. The association says the realistic target should be 2.5 to 3 litres per person per year, once accounting for the roughly 25 per cent of oil absorbed by food during cooking.

The data reveals a direct correlation between collection rates and the density of oleões — the dedicated collection points for used cooking oil. Municipalities with denser networks or complementary door-to-door collection systems, such as Maia, Seixal, and Oeiras, perform significantly better. Many others lag far behind.

A biofuel opportunity going to waste

Used cooking oil is the most sustainable feedstock for producing biofuels, according to Zero. These fuels can substitute imported fossil fuels in road, maritime, and aviation transport. If the domestic collection potential were fully realised, Portugal could produce 25 to 30 million litres of biofuel per year — between 25 and 30 times the current output.

The timing of Zero's appeal is pointed. With global energy markets still volatile and Portugal spending billions annually on fossil fuel imports, the association argues that "continuing to waste used cooking oils is an irresponsibility the country cannot accept." Portugal already has the industrial and business capacity to process the oil — what is lacking is the collection infrastructure and the political will to build it.

Galp's Sines biofuel plant adds context

The call comes as Galp Energia prepares to begin commercial production of biodiesel and sustainable aviation fuel at its EUR 400 million HVO plant at the Sines refinery. The facility, a joint venture with Japan's Mitsui, will have capacity to process 270,000 tonnes per year of waste materials — including used cooking oils — into renewable fuels. A secure domestic supply chain for feedstock would be a natural complement to the industrial investment.

What Zero is proposing

The association has called on Portuguese citizens to store used cooking oil in sealed plastic containers and deliver them to collection points, rather than pouring them down sinks or toilets. It is urging municipalities to "urgently strengthen the network of oleões" and calling on the government to designate used cooking oil as a "priority flow for the circular economy and material security."

Sources: Associação ZERO (direct communiqué), Observador, Jornal de Negócios. Additional context: Reuters reporting on Galp's Sines HVO project.