Coal to Biomass Conversion as a Path to Sustainability: A Hypothetical Scenario at Pego Power Plant (Abrantes, Portugal)

Abstract

Energy consumption is associated with economic growth, but it comes with a toll regarding the environment. Renewable energies can be considered substitutes for fossil fuels and may contribute to reducing the environmental degradation that the world is presently facing. With this research, we aimed to offer a broader view of the state-of-the-art in this field, particularly regarding coal and biomass. The main objective is to present a viable and sustainable solution for the coal power plants still in operation, using as a hypothetical example the Pego Power Plant, the last operating coal fueled power plant in Portugal. After the characterization of land use and energy production in Portugal, and more particularly in the Médio Tejo region, where the power plant is located, the availability of biomass was assessed and it was concluded that the volume of biomass needed to keep the Pego power plant working exclusively with biomass is much lower than the yearly growth volume of biomass in the region, which means that this transition would be viable in a sustainable way. This path is aligned with policies to fight climate change, since the use of biomass for energy is characterized by low levels of GHGs emissions when compared to coal. The risk of rural fires would be reduced, and the economic and social impact for this region would be positive.

Assessment of Woody Residual Biomass Generation Capacity in the Central Region of Portugal: Analysis of the Power Production Potential

“…In this scenario and given the availability of biomass in the Médio Tejo subregion, which is approximately 170,000 t•yr −1 , it seems possible to create a value chain for residual biomass, which would contribute to the valorization of an endogenous resource until now almost always neglected. It could also contribute to the resumption of the power plant activity and mitigate the negative impacts of the local socioeconomic system, as presented by Casau et al, which could somehow be reversed and/or minimized in this scenario [26]. However, coal-fired power plants, such as the Pêgo Power Plant, do not allow the direct use of residual biomass, as the coal handling system is quite different from those used for handling biomass.…”

“…In other words, it was a production unit that operated at the request of the grid when it was unable to ensure the capacity to respond to consumption using other sources, namely renewable sources, and natural gas. Casau et al presented an estimate for coal consumption for the year 2019, of 689,419 tons [26]. If an average low heating value of 22 MJ•kg −1 for the coal used is considered, it will correspond to the potential energy production of 15,167,218,000 MJ•yr −1 (4,213,116 MWh•yr −1 ), which corresponds to a potential consumption of residual biomass between 1,448,636 and 1,812,093 t•yr −1 .…”