| Resumo : |
Integrating renewable energy sources into energy systems presents challenges associated with its variable nature, such as the need to balance generation and demand. Furthermore, concerns regarding the optimal siting of renewable energy installations and their potential negative effects on biodiversity and land use remain unaddressed. We fill this gap by analyzing the long-term Brazilian energy system with two highly detailed engineering energy models. In the first part, we focus on offshore wind energy and examine its optimal placement and potential synergy with the existing hydropower system. Factors such as distance to shore and water depth are considered. Our findings reveal a strong complementarity between offshore wind energy and hydropower, with optimal farm locations identified in Brazil's Northeast and South regions. Remarkably, offshore wind farms alone can eliminate 54.4 million tons of CO2, which corresponds to 97% of current emissions from the power sector, without additional electricity storage. Then, we develop a sector coupling model to explore solutions through electrification and net zero pathways while considering the conservation of ecologically important lands. We observe that avoiding new energy infrastructure deployment on these ecologically relevant lands incurs minimal to no additional costs for the energy system. Wind farms and rooftop photovoltaic systems emerge as central technologies across all scenarios. Bioenergy significantly reduces emissions; however, its implementation requires a substantial land area for feedstock production, leading to land conversion. The converted land primarily consists of degraded pastures, resulting in a positive environmental-wise shift in land use. In the net zero scenarios, there is a substantial increase in demand for hydrotreated vegetable oil and sustainable aviation fuel, leading to a significant expansion of land area dedicated to soybean crops, accounting for approximately 49% of current croplands. Without significant progress in the energy transition, our projections indicate that emissions could double by 2050. However, in the electrification and net zero scenarios, emissions decline by 40% to 91% compared to the baseline level of 915 million tons of CO2. Our analysis emphasizes the importance of considering sustainability in long-term energy planning. By avoiding new energy infrastructure in ecologically relevant areas, embracing renewable energy technologies such as wind farms and rooftop PV, and optimizing land use, Brazil can contribute substantially to addressing climate change and biodiversity loss while fostering a sustainable energy system with energy security. |