The “National Atlas of Sustainable Green H2” is a tool based on georeferenced information that follows defined criteria in the development of scenarios to assess the suitability of the location of green hydrogen production projects with regard to: (i) necessary resources to power hydrogen production plants through water electrolysis; (ii) land use conditions for the implementation of green hydrogen production units, and (iii) factors that enhance the commercialization of the produced hydrogen. Based on this “National Atlas of Sustainable Green H2” tool, we present 4 maps referring to 4 scenarios that identify the “best” areas for green hydrogen production according to the basic rationale of each scenario. The 4 maps represent the following scenarios: scenario A “Diversified”, scenario B “Drought, Gas Grid and Transport”; scenario C “Drought and gas consumers”; scenario D “Prospective”. Each scenario was developed based on 3 sub-indices (i) proximity to water sources, (ii) proximity to energy sources and (iii) ease of commercializing green H2 on the market. The water sub-index consists of a maximum of 7 indicators considering the proximity to the following potential water sources: surface water bodies, wastewater treatment plants (WWTPs), public water network, groundwater, seawater, multi-purpose irrigation grid, water scarcity index. The energy sub-index consists of a maximum of 6 indicators, namely: solar resource, onshore wind resource, offshore wind resource, proximity to bioelectricity producers, proximity to hydropower producers, proximity to the power grid. Finally, the market sub-index is made up of a maximum of 5 indicators, including proximity to: potential industry consumers of H2, potential transport consumers of H2, potential consumers of H2 as raw material, large CO2 emitters. Each final map excludes from potential project locations land occupation that proves to be inappropriate. The following are not yet considered: easements and public utility restrictions, RAN and REN areas, Territorial Planning Plans, municipality land planning (PDM), SEVESO Directive hazardous zones, protected areas under the Water Framework Directive , seismicity, flood risk and/or geologically unstable areas (erosion, landslides, etc.). This Atlas requires a detailed analysis of sites considering all applicable legislation. The geographic information used has inherent limitations regarding date, scale, resolution and sources. Furthermore, the viability assessment for a specific project requires detailed information that goes beyond the variables contained in this Atlas and considers other decision-making and legal compliance factors, which cannot be considered at this scale.

The Biomethane Atlas serves to support the identification of the most favorable locations for the implementation of biomethane production units, considering proximity to biogas sources (potential producers), potential consumers, and/or the gas network. It is developed using GIS software for mainland Portugal. The analysis is performed to identify clusters of producers/consumers in proximity, considering the division of the country into a 20km² grid (278 grid squares in mainland Portugal). For each of these, the current potential quantity of biomethane production in m³/year was estimated for the following types of potential producers: (1) Waste and Wastewater: municipal waste landfills, industrial waste landfills, and wastewater treatment plants; (2) Agro-industry: Other food products; Milk; Breweries; Slaughterhouses; Tomatoes; Juices/Salads; Rice husks and Dried fruits; (3) Olive mills and wineries: Olive pomace; Olive mills; Wineries and distilleries; (4) Intensive Livestock Farming: Poultry; Ruminants and Pigs; (5) Agricultural Byproducts: Tomatoes; Corn; Rice paddies; Olive grove pruning; Orchard pruning and Vine pruning. The following potential consumers were considered: (1) Refineries and CCGT Combustion Plants; (2) Industry: Glass; Chemical; Cement; Ceramics; Paper/Cardboard; Agri-food and Textile; (3) Vehicle gas refuelling stations; (4) Autonomous Gas Units; and (5) Injection points in the natural gas grid. A dimensionless index was developed that characterizes each grid square according to its suitability and ranges from 0 to 100 (100 is higher/better). The index can be viewed only for producers, for consumers, and for the combination of producers and consumers. A cell with many potential producers of high volumes of biomethane and potential consumers will have a higher value in the index. The location of production projects and areas with limitations for the application of digestates in soils are also shown. The Atlas does not replace case-by-case analysis of project location or licensing. It should be used for informational purposes only. The scale of analysis used is limited by the resolution and accuracy of the underlying information.

COMET's Database. The dataset for Portugal was updated in the framework of project CSA-GSEU, WP3 Geoenergy, Geological storage thematic working group.