Strengthening Spain’s commitment to renewable and sustainable heating and cooling with biomass networks

The path of biomass district heating systems in Spain
The journey for biomass heating and cooling networks in Spain began in 2010, when the country had only 71 networks, totaling 48.26 MW. Since then, infrastructure expansion has been consistent, with an average annual growth rate of 5.9% in network numbers and 11.6% in installed capacity.

By 2023, the average network capacity grew to 0.95 MW from 0.68 MW in 2010, marking clear progress toward more robust systems with broader reach. This scalability implies both technical optimization and greater capacity to serve residential buildings, public services, and even industrial complexes within a single energy network.

The geography of biomass networks: Catalonia and Castile and León as key drivers
Catalonia and Castile and León lead the adoption and expansion of biomass networks in Spain, jointly contributing 61% of the country’s total networks and 56% of installed capacity. Catalonia has more networks of smaller scale, typically covering public buildings and residential needs through microgrids up to 800 kW. Examples include the established Molins de Rei heat network, built in 2000, which provides heating and hot water for around 2,200 residents, and the network at the Autonomous University of Barcelona, which powers university and residential buildings on campus.

In contrast, Castile and León has focused on higher-capacity networks for residential heating, mostly led by the public company SOMACYL and through public-private partnerships. Some of Spain’s largest and most complex projects are located in this region, like the Soria city network by the company REBI, which serves over 5,000 homes and multiple institutional buildings, and the Valladolid networks with a total of 67 connected buildings.

Environmental impact: emission savings and energy efficiency
In 2023, biomass district heatings prevented the emission of approximately 21,950 tons of CO₂ by replacing fossil fuels with forest and agricultural biomass, mainly wood chips. This annual biomass consumption of 20,280 tons generates 823,072 MWh of thermal energy, enough to meet the heating and hot water needs of a significant number of users across various regions.

Most networks supply energy to residential and public buildings, although some also include industries or agricultural facilities, ensuring a steady year-round thermal demand and enhancing overall network efficiency.

Looking ahead: Biomass district heating consolidation and expansion

The future of biomass heating and cooling networks in Spain presents both challenges and strategic opportunities:
1. Expanding use in high-density and rural areas: While Catalonia and Castile and León are leaders, adoption in other regions is still limited. Implementing these networks in densely populated urban areas and rural areas with biomass resources could optimize energy and environmental benefits.
2. Funding for installations: European funds from the Recovery Plan and Next Generation EU aid programs offer a unique chance to finance new networks and modernize existing ones. Public-private partnerships can be essential for attracting investment and ensuring the long-term sustainability of projects.
3. Increasing technology integration: The integration of thermal storage systems and combination with other renewables, such as solar and geothermal, represents a key area for improvement. Developing cogeneration and trigeneration systems can facilitate cooling provision, broadening the functional scope of networks.
4. Enhanced technical training and public awareness: Training technicians and raising public awareness of biomass benefits are essential for the expansion of new networks. Training professionals in areas like maintenance and operation can improve performance and maximize resource use.
As the country progresses toward its carbon neutrality goals for 2050, district heatings are becoming a viable, low-impact solution to meet the thermal demands of key sectors. The future of biomass in Spain depends not only on investment and technological development but also on the commitment of citizens, businesses, and governments to a sustainable, decentralized energy model.