The Future of Sustainable Energy Supply in Southwest Finland

The study describes the administrative and economic operating environment of industrial solar power, its environmental impacts, and criteria for its location. The perspectives on location are grouped into favorable, restrictive, and conflicting factors in a so-called multi-criteria framework. Favorable factors include, for example, proximity to power lines, substations, and road networks. Location is restricted by natural and cultural values as well as residential areas. In addition, conflicting, multifaceted factors were examined that may support or challenge location when project cases and their specific characteristics are studied more closely. Multifaceted factors may include, for example, co-production with other energy production in the same area or location on different types of agricultural land. The various factors were grouped into a recommended multi-criteria framework for location. Based on the criteria, zonal spatial data analyses were conducted at the regional level. The environmental impacts of industrial solar power were assessed using the Do No Significant Harm principle based on the EU taxonomy, which is a condition of the funding received from the Ministry of the Environment for the study series.

The sub-study on the location of industrial solar power in Southwest Finland was completed in May 2024. The study has been published as a PDF report. In addition, a separate map service has been published for the thematic maps of the spatial data analyses, where they can be explored in more detail. The report and maps are informational preliminary studies as background for the regional planning process. Background studies are not legally binding planning documents. The multi-criteria framework developed is a recommendation by the Regional Council of Southwest Finland. Municipalities and other stakeholders may apply the criteria when developing project-specific solutions based on more detailed baseline data.

Explore the sub-study:

On the Location of Industrial Solar Power in Southwest Finland VSL 2024 (PDF)
Areas Suitable for Industrial Solar Power in Southwest Finland (link to map service)

The possibilities for locating onshore wind power in Southwest Finland were re-examined, as the sizes and efficiencies of wind turbines have more than doubled over the past ten years. At the same time, their spatial requirements and impacts have also increased. On the other hand, administrative regulation has tightened, for example, with regard to external noise. The current wind power phase regional plan for Southwest Finland was approved in 2014, and its background studies were conducted in the early 2010s.

The update study on onshore wind power in Southwest Finland 2025 began by describing the current state and impacts of wind turbines in terms of their spatial requirements, operating environment, and limited implementation in Southwest Finland. In the actual analysis section of the study, suitable locations were identified in three stages: first, restrictions arising from legislation and other planning regulations in relation to people, natural values, cultural heritage, and critical infrastructure and defense were updated. Based on these criteria, a location-based exclusion analysis was conducted. A total of 30 potentially suitable areas of at least one square kilometer were identified as result areas. In the second analysis stage, consultant FCG assessed the suitability of these areas as regional groups with a landscape emphasis. In the third stage of additional examinations, the impacts of the largest, potentially regionally significant areas on natural and recreational values were further analyzed.

Based on the study phases, it is proposed that in the future, the phase regional plan should designate one regionally significant wind turbine area and three smaller wind turbine sites. All of these are also designated in the current regional plan, and wind farm projects are already pending or operational at these locations. In addition, one possible new site requires further studies. Other old wind power designations are proposed to be removed (a total of 17 areas, 12 sites, and 1 study area), as they unfortunately no longer meet current criteria for suitable locations.

The studies provide informational background for regional planning work and are conducted as required by law. However, they are not actual legal planning documents, but rather produce justified proposals for the multi-year regional planning process. This study particularly provides background for the ongoing phase regional plan for waters and energy in Southwest Finland.

Onshore Wind Power in Southwest Finland 2025
Presentation slides from the webinar held on 6 May 2025

The importance of electricity transmission connections has grown rapidly in recent years. Industry is electrifying, and heat production is also shifting from combustion processes to various electricity-linked environmental heat and storage solutions. Charging electric vehicles adds its own contribution, especially to peak power demand during the cheapest hours. Regionally, the challenge is that electricity production is increasingly concentrated on the west coast and in the north, while electricity consumption centers are in southern Finland. The challenges of electricity transmission connections are currently affecting the entire country.

The high-voltage power line designations in the Southwest Finland regional plan were last updated in the regional plan for natural values and resources in 2021. They are largely up to date. Nevertheless, possible update needs were also identified due to the rapid development of the energy sector. Grid companies operating in Southwest Finland were asked for comments on update needs for the more distant future. Some feedback comments supplementing current designations were received, particularly regarding preliminary connection needs in south-north directions.

National Hydrogen Transmission Connections

Gasgrid Finland Oy has been planning a national hydrogen transmission network since spring 2024. The environmental impact assessment phase began in summer 2025, and the routing of the national hydrogen network has largely taken shape, although some changes may still occur as a result of the EIA process. The hydrogen network crosses Southwest Finland in two directions: from Naantali to the northeast and from Loimaa via Salo to the southeast. A hydrogen network junction will be formed in Loimaa. The national hydrogen transmission network must also be designated as a new element in the Southwest Finland regional plan. It is not in conflict with other land use designations in the regional plan. The sub-study also describes the properties of hydrogen, the hydrogen economy, and land use conditions, as the broader utilization and further processing of green hydrogen is developing as a new matter.

Emerging Energy Technologies

There are also many new, increasingly common technological solutions in electricity and heat production and storage. Their scales are most often closer to the levels of municipal planning, project planning, and permitting. Nevertheless, emerging energy technologies were also identified as part of the study series, and a separate appendix on them was commissioned from Ramboll Oy. Strengthening technologies addressed included various forms of environmental heat, electricity and heat storage, small modular nuclear power, and hydrogen and synthetic fuels. The project type cards in the appendix describe their main features as well as requirements for land use and possible connections to regional planning. However, no designation needs requiring updates specifically at the regional plan level were identified.

Transmission Connections and Emerging Energy Technologies

The final summary section of the series interprets the study series as a whole. The summary specifies perspectives and recommendations for designations and regulations for actual regional planning work based on the sub-studies. The interpretation is introduced with a situational description of the energy system as an operating environment, as energy topics are a considerably broader stream than regional planning; planning is linked to the energy transition as one component. The summary reviews the most essential results of the sub-studies and the interpretations made from them for the overall land use planning perspective.

Summary of the Background Study Series on Sustainable Energy Supply in Southwest Finland