## 4 A Hypothetical Scenario Analysis  
Biomass is the third most common renewable energy source in Portugal, and its production has significantly increased since the early 2000s. This growth is due to a strategic initiative starting in 2006, allocating 100 MW for electricity generation from forest biomass and an additional 150 MW for Public Interest Projects. In 2000, Portugal's biomass energy capacity was 427 MW, which rose to 891 MW by 2020. The Pego Power Plant, located in Abrantes, focuses on the biomass potential of the Medio Tejo region (Figure 4). Data from the 6 th National Forest Inventory (2019) show that 46% of the Medio Tejo region is forested, 10% more than the rest of the country. To estimate the biomass yield in Portugal's Medio Tejo region, the two primary tree species, maritime pine (Pinus pinaster) and eucalyptus (Eucalyptus globulus), were taken into account, as they comprise 80% of the total forested area in the region (information available at [[https://www.icnf.pt/florestas/fhestudosdocumentosestatisticasindicacores](https://www.icnf.pt/florestas/fhestudosdocumentosestatisticasindicacores)]([https://www.icnf.pt/florestas/fhestudosdocumentosestatisticasindicacores](https://www.icnf.pt/florestas/fhestudosdocumentosestatisticasindicacores)), accessed on 15 January 2023). The growth volume for these species stands at 2933 Mm\({}^{3}\) for maritime pine and 3332 Mm\({}^{3}\) for eucalyptus, with a total living biomass of 1954 kt and 2628 kt, respectively [104]. If the total biomass required to transition the Pego coal-fired power plant in Portugal to biomass is less than the annual growth volume of these species (6265 Mm\({}^{3}\)), it could be deemed theoretically sustainable for a consistent biomass supply [105, 106, 107]. To estimate the biomass needed to replace coal, data from the DGEG-Direcao-Geral de Energia e Geologia on the 2019 coal balance sheet were analyzed (accessed on 12 November 2022, available at [[https://www.dgeg.gov.pt/en/statistics/energy-statistics/coal/](https://www.dgeg.gov.pt/en/statistics/energy-statistics/coal/)]([https://www.dgeg.gov.pt/en/statistics/energy-statistics/coal/](https://www.dgeg.gov.pt/en/statistics/energy-statistics/coal/))), as public data on Pego's coal consumption were unavailable. The total volume of bituminous coal used for energy generation was divided between the two coal-fired power plants in Portugal in 2019, considering their installed capacities. According to REN reports, Sines had a capacity of 1180 MW and Pego 576 MW, totaling 1756 MW (accessed on 12 November 2022, available at [[https://www.ren.pt/en-GB/investigores/relatorio_annual](https://www.ren.pt/en-GB/investigores/relatorio_annual)]([https://www.ren.pt/en-GB/investigores/relatorio_annual](https://www.ren.pt/en-GB/investigores/relatorio_annual))). In 2019, the total coal used for energy production was 2,101,758 tons. Assuming both power plants had similar efficiencies, Sines used 1,412,339 tons (67.2%) and Pego  
Figure 4: Location of the Médio Tejo region. 689,419 tons (32.8%). To support this assumption, greenhouse gas (GHG) emissions from each plant were compared. Between 2008 and 2017, Sines contributed 12% of national GHG emissions and Pego 5%. This similarity supports using an installed capacity to estimate coal consumption at each plant. According to the CO\({}_{2}\) emissions control by the EU (accessed on 23 March 2023, available at [[https://climate.ec.europa.eu/eu-action/eu-emissions-trading-system-eu-ets/union-registry_en#tab-0-1](https://climate.ec.europa.eu/eu-action/eu-emissions-trading-system-eu-ets/union-registry_en#tab-0-1)]([https://climate.ec.europa.eu/eu-action/eu-emissions-trading-system-eu-ets/union-registry_en#tab-0-1](https://climate.ec.europa.eu/eu-action/eu-emissions-trading-system-eu-ets/union-registry_en#tab-0-1))), the Pego Power Plant emitted 1,018,548 tons of CO\({}_{2}\) in 2019 and 875,259 tons in 2020. To maintain the same electricity production, 689,419 tons of torrefied biomass (with a heating value of 21 GJ/t, like coal) would be needed.