From biogas to biomethane
In the early years, biogas was commonly burned in special engines to generate electricity. This enabled the gas recovered from landfills and treatment plants to be valorised, reducing greenhouse gas emissions and obtaining renewable energy.
However, the energy transition and the need to decarbonise sectors such as industry and transport have led to a shift from raw biogas (a blend of methane and CO₂) to biomethane (purified gas with a similar quality to natural gas).
This process, known as upgrading, entails eliminating the CO₂ and other compounds to achieve a methane concentration of over 95%. In this form, the gas can be fed into the natural gas network (replacing fossil fuels) or used in transport and industrial processes as a renewable source.
As a result, biogas is no longer just a local resource, becoming instead a versatile energy vector, helping to meet targets on climate neutrality.
First biomethane plant in the Basque Country
Since 2023, EVE and other organisations have been running Metabarri SA. The plant uses domestic organic matter from brown recycling bins across the province of Bizkaia to produce biomethane. The project involves building and commissioning a biomethanation plant for valorising the organic fraction to produce biogas, which is subsequently upgraded and fed into the natural gas network.
The plant at the Artigas Eco-Park will handle approximately 50,000 tonnes of organic waste per year. It is due to come on line at the end of 2026, with estimated output of 40-42 GWh per year — capable of meeting the electricity needs of over 12,000 homes.
Strategic Framework of the Project
This project has been developed as part of energy transition and sustainability policies and plans for the province of Bizkaia and the Basque Country more generally. It is in line with the targets on waste reduction and recovery set in the Bizkaia 2030 Integrated Waste Prevention and Disposal Plan (PIPGRB 2030) and the Basque Waste Prevention and Disposal Plan 2030. It also meets the directives of the Energy Transition and Climate Change Act and is included in the Basque Energy Strategy 2030 and the Energy Transition and Climate Change Strategy 2030. The project will also contribute to the Basque Industry 2030 Plan and is directly linked to the ‘Renewable Fuels Hub’ Transformational Project, driving innovation and decarbonisation in the energy sector.
Future outlook
The Basque Energy Agency, Ente Vasco de la Energía (EVE) is working to identify new opportunities to expand biomethane production in the Basque Country, incorporating advanced technologies and promoting public-private partnerships to ensure sustainable and competitive development.
Historical actions in biogas plants
Since 1992, Ente Vasco de la Energía has been promoting biogas as an essential element in the Basque energy transition. Biogas is a renewable energy source which is obtained from organic waste. It contributes to decarbonisation, the circular economy and energy independence.
The first facility promoted by EVE for valorising landfill biogas was BioArtigas, S.A. at the Artigas landfill (Alonsotegi, Bizkaia). It was created in 1992 as a joint venture under the Bilboener brand.
The two aims were to degas the landfill, extracting the methane (CH₄) to reduce greenhouse gas emissions, odour and the risk of explosion, and to generate renewable electricity — up to 10,000 MWh/year using biogas engines.
The plant is still operational, though currently at depletion phase, since no new organic matter is being received at the site and the amount of available biogas is progressively decreasing.
Using accumulated waste gas, the facility can continue to operate for about another 30 years. Total output in 2025 (in conjunction with the Ordunte hydroelectric plant) was estimated at 3,500,000 kWh.
The second facility to be developed by EVE for valorising local landfill biogas was BioSanMarkos, S.A., created in 1994 as a joint venture to manage the biogas generated at the San Marcos landfill (Donostia/Renteria).
The twin objectives were degasification of the landfill and biogas-fired renewable power generation, with an estimated capacity of up to 15,000 MWh/year (greater than the BioArtigas plant).
The plant is still in operation, although activity has dropped off due to progressive depletion of the landfill.
Biogardelegi S.A. was created in 2003 as a joint venture to manage the biogas recovered at the Gardelegi landfill (Vitoria-Gasteiz). It forms part of EVE’s historical strategy of reducing emissions and generating renewable electricity from waste.
It shared the same primary objectives as the other plants: landfill degasification to prevent methane emissions (CH₄), limit odours and reduce environmental risk, and energy valorisation of biogas for renewable electricity.
The plant is still in operation, although production has dropped due to progressive depletion of the landfill. It continues to generate renewable electricity, thus contributing to a reduction in greenhouse gas emissions.
Biosasieta S.A., was also set up in 2003. The project was developed jointly by EVE and the Sasieta association of municipalities. Its aims are similar to those of other landfill gas facilities, in this case to degas the landfill at Sasieta (Beasain) eliminating methane (CH₄) and to secure the site. The plant generated around 3,400 MWh/year, which was sold to the grid. The facility is currently at depletion phase.
