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With its abundance of renewable energy potentials, not only for hydropower and bioenergy, but also for wind and solar, Brazil provides good prospects for a carbon neutral energy system. The role of an enhanced coupling of the power, heat and transport sectors in such systems is not yet fully understood. This paper analyses the least-cost composition and operation of a fully renewable power supply system as part of a carbon neutral energy supply in Brazil. It relies on the application of the high-resolution energy system model REMix. Our analysis reveals that the expansion of wind and solar power is more cost-efficient than the construction of additional hydroelectric plants. This is favoured because the existing hydroelectric plants offer large capacity of dispatchable power to compensate for fluctuations, and thus no additional storage is necessary. Furthermore, the REMix analysis indicates that varying shares of solar and wind power technologies as well as the spatial distribution of power generation have only a small influence on supply costs. This implies that the transformation strategy in Brazil can be primarily based on other criteria such as regional development, public acceptance, environmental impact or industrial policy without major impacts on system costs. [ABSTRACT FROM AUTHOR]

One of the technologies that stand out as an alternative to provide additional flexibility to power systems with large penetration of variable renewable energy (VRE), especially for regions with high direct normal irradiation (DNI), is concentrated solar power (CSP) plants coupled to thermal energy storage (TES) and back-up (BUS) systems. Brazil can develop this technology domestically, especially in its Northeast region, where most of VRE capacity is being deployed and where lies most of the CSP potential of the country. This work applies the Capacity Expansion Model REMix-CEM, which allows considering dispatch constraints of thermal power plants in long-term capacity expansion optimization. REMix-CEM calculates the optimal CSP plant configuration and its dispatch strategy from a central planning perspective. Results showed that the hybridization of CSP plants with jurema-preta biomass (CSP-BIO) becomes a least-cost option for Brazil by 2040. CSP-BIO contributes to the Northeast power system by regularizing the energy imbalance that results from the large-scale VRE expansion along with conventional inflexible power plants. CSP-BIO plants are able to increase frequency response and operational reserve services and can provide the required additional flexibility that the Northeast power system of Brazil will require into the future. [ABSTRACT FROM AUTHOR]

This paper contributes to the analysis made by an article recently published in this journal [1]. The purpose of this manuscript is to bring new contributions to this complex subject, namely the limits to the penetration of variable renewable energy (VRE) into national grids. A detailed and advanced model has been used in this work in order to add further contributions to De Jong et al. [1] findings. For example, by applying an optimization model, we were able to show that the high wind penetration (65%) almost without curtailment found by [1] might not happen, mainly due to inflexibility constraints in Brazilian power plants and also to transmission limits. [ABSTRACT FROM AUTHOR]

Brazil is looking for innovative alternatives to supply the country's increasing electricity demand and provide flexibility to cope with higher shares of variable renewable energy (VRE). Concentrated solar power (CSP) can help solving this double challenge. Three energy planning tools, namely MESSAGE-Brazil, TIMES-TiPs-B and REMIX-CEM-B, have been combined to analyze the opportunities that CSP plants offer to the power system and to the wider energy system of the country. This work shows that CSP can be a cost-effective option under stringent mitigation scenarios. CSP can provide firm energy and dispatchable capacity in the Northeast region of Brazil, optimally complementing wind and PV generations. Moreover, CSP can offer additional flexibility to the Northeast power system of the country, especially during winter, when the hydrological period is dryer. Results show synergies between CSP and other power supply technologies with small cost differences between the baseline and CSP-forced scenarios. [ABSTRACT FROM AUTHOR]

This study aims to quantify the environmentally sustainable and economically feasible potentials of agricultural and agro-industrial residues to generate electricity via direct combustion in centralised power plants in Brazil. Further, the energy savings and greenhouse gas (GHG) reduction potential of replacing natural gas-based electricity by bioenergy have been assessed. To this end, a methodology has been developed based on an integrated evaluation, incorporating statistical and geographical information system (GIS)-based analysis, and a life-cycle-assessment approach. Results reveal that the environmentally sustainable generation potential is nearly 141 TWh/year, mainly concentrated in the South, Southeast, and Midwest regions of the country. Sugarcane, soybean and maize crop residues are the major feedstocks for available bioenergy. On the other hand, the economic potential is far lower, accounting to 39 TWh/year. The total GHG mitigation is nearly 18 million tonne CO 2 e and could reach 64 million tonne CO 2 e yearly, if the technical potential is considered. The gap between technical and economic potentials implies that constraints to bioenergy are not related to a lack of resources, but rather associated to economic, logistical, regulatory and political barriers. [ABSTRACT FROM AUTHOR]

This work evaluates implications of incorporating LCA-GHG (life cycle assessment of GHG emissions) into the optimisation of the power generation mix of Brazil through 2050, under baseline and low-carbon scenarios. Furthermore, this work assesses the impacts of enacting a tax on LCA-GHG emissions as a strategy to mitigate climate change. To this end, a model that integrates regional life cycle data with optimised energy scenarios was developed using the MESSAGE-Brazil integrated model. Following a baseline trend, the power sector in Brazil would increasingly rely on conventional coal technologies. GHG emissions from the power sector in 2050 are expected to increase 15-fold. When enacting a tax on direct-carbon emissions, advanced coal and onshore wind technologies become competitive. GHG emissions peak at 2025 and decrease afterwards, reaching an emission level 40% lower in 2050 than that of 2010. However, if impacts were evaluated through the entire life cycle of power supply systems, LCA-GHG emissions would be 50% higher in 2050 than in 2010. This is due to loads associated with the construction of plant infrastructures and extraction and processing of fossil fuel resources. Thus, taxes might not be as effective in tackling GHG emissions as shown by past studies, if they are only applied to direct emissions. [ABSTRACT FROM AUTHOR]