Addressing Acceleration Areas for Renewable Energy Development in the European Union (EU): A Case Study of Mainland Portugal

The urgent need to accelerate the energy transition in the European Union has made spatial planning a key tool for effective and equitable deployment of renewable energy. Directive (EU) 2023/2413 requires Member States to designate “renewable acceleration areas” where renewable projects can be rapidly implemented with minimal environmental impact. However, the methodological basis for identifying such areas remains underdeveloped and uneven across countries. This paper proposes a methodological framework for identing these areas using the case of wind energy implementation in mainland Portugal, with implications for other EU countries. Results show that, under the most restrictive scenario, wind energy development is incompatible or highly inadvisable in 95% of the territory. Still, land remains available for installing 11,513 turbines, equating to 23,026 MW (assuming 2 MW per turbine). A less conservative interpretation of slope restrictions would allow for the installation of 616 additional turbines. These findings highlight that particular attention should be paid to technical criteria, such as slope, in the same way that environmental protection and population-related factors are critically reviewed. It also emphasizes the need to assess “incompatible” areas more critically, categorizing them by the type and number of constraints. Proximity to energy demand is highlighted as a key factor for enhancing self-sufficiency and reducing externalities. Finally, it is recommended that suitability weightings be delegated to local planners, fostering flexibility and local empowerment with the involvement of experts familiar with the territory to be planned. This approach promotes balanced and flexible renewable energy zoning to the implementation of EU renewable energy targets and planning mandates.