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The growing interest in fully decarbonizing worldwide energy systems requires abandoning traditional generation expansion planning in favour of other flexibility-enabling energy system planning tools allowing the integration of energy storage and sector coupling. Therefore, this paper proposes a mixed-integer linear programming formulation focused on enabling flexibility provision on integrated energy systems targeting independent sizing of power and energy capacities for simultaneous generation and storage expansion planning. The optimization problem minimizes investment, maintenance, operation and emissions costs over a 20 year horizon with hourly resolution. In this context, islands represent suitable study cases for the energy transition due to their exceptional renewable availability, and fast-paced development; despite being regions with extreme external dependence and isolation. In particular, the island of Santiago, Cape Verde is selected as study case given its existing targets regarding reaching 50 and 100% renewable shares in 2030 and 2040, its data availability, and the extreme seasonal variation in wind and solar resources. Four scenarios are considered. The first and second dismiss flexibility: business as usual (BAU), and another one aligned with the government goals (Green). Then, the other two exploit it: one equivalent to Green, FlexG, and a last one finding the Optimal. In addition, three energy demand growth levels are considered in order to reduce uncertainty, corresponding to 1, 3 and 5%. Last, a sensitivity analysis with three additional scenarios is performed to provide a thorough view of Cape Verde's energy future. The results highlight the importance of flexibility exploitation which provides up to 85% savings and allows to decarbonize other sectors via electrification. • Solar and hydro pumped storage drive the transition. • Wind power's role increases in hydrogen intensive and surface constraint scenarios. • Integrating flexibility into generation expansion planning halves power needs. • The current paradigm is the most expensive option, doubling emissions in 20 years. • The Optimal configuration achieves 96% renewable penetration. [Display omitted] [ABSTRACT FROM AUTHOR]

This article investigates the history of proposals to use vegetable oils as fuel in Brazil beginning in the 1920s up to the current National Program for Biodiesel Production and Use – PNPB. The characteristics of vegetable oils markets and of the oil products market, as well as the incentive mechanisms formulated for biodiesel implementation, are analyzed. Although the research focuses on the Brazilian experience, initiatives of biodiesel insertion, or those already implemented in countries with significant oilseeds production are also studied. The results allow concluding that attempts to make biodiesel production viable confront several barriers. Comparative analysis revealed that vegetable oil world prices tend to be higher than the equivalent fossil oils. In Brazil, the initiative in the 1970s lacked political alliances to overcome the difficulties imposed by market conditions such as those that benefited the National Alcohol Program –Proalcool. In the resumption of the 2000s with PNPB, despite intense articulation and institutional incentives, arising from the limited scale of production of the feedstock from incentived family farming and from the nature of markets of vegetable oils, as food or fuel, and of fossil oils, especially regarding the respective regulating prices. The incentives provided by the PNPB seem insufficient for vegetable oils to prefer the energy market instead of benefiting from higher surplus in alternative food markets. [ABSTRACT FROM AUTHOR]

Abstract: This article aims to investigate the introduction, sustenance and consolidation of bioethanol in Brazil. It presents an analysis of its introductory stage, from the first decades of the 20th century until the early 1970s, when, in a second stage, additional measures allowed for its consolidation and maturity, under the widely known Proalcool. The paper presents a historical reinterpretation of the policies, mechanisms and instruments adopted in both stages, aiming to highlight the economical and political links. It is concluded that the interests of the agrarian elites, operating at the political level, and the fuel supply crisis during Second World War were basic during the first stage, to sustain a productive and logistic capacity and maintain ethanol alive as an automotive fuel. It is also concluded that the launching of Proalcool represented a transition combining the interests of the sugarcane agribusiness, burdened by the drop in sugar prices, and the need to equilibrate the balance of payments due to the oil shocks of the 1970s. Ethanol supply shocks harmed its credibility and its commercial consolidation was only possible through the introduction of flex-fuel vehicles with expectations strongly relying on climate change mitigation actions. [Copyright &y& Elsevier]

The production of decentralized renewable electricity often collides with provisioning, regulating and cultural services of the landscape. In this paper we operationalize the landscape service approach and generate conflict maps between three renewable energies (wind; PV; forest biomass) and six competing landscape services (nutrition and materials; aesthetics; physical and experiential interactions; heritage and symbolic content; water and liquid flows; lifecycle maintenance, habitat and gene pool protection). Media content analysis and expert interviews were used to ground-truth the national conflict maps in several Swiss regions and to understand to what degree the national conflict assessments match the regional and local perceptions of these conflicts. In Switzerland (approximately 40,000 km 2 ) biomass from forests is by far the least conflicting renewable energy, followed by PV on roofs. For the latter 68% of the technically feasible energy potential can be generated with low conflicts, and more is expected with new materials. Wind has a high conflict potential: only 12% of the technically feasible energy potential is low conflict. PV on open land, marginal land and shrubland, is – at the moment – not currently feasible in Switzerland. The accuracy of our conflict assessment is sufficiently high to estimate the proportion that socially sustainable energy could cover of the overall energy gap of 22–25 TWh/yr caused by the phase-out of Swiss nuclear plants by 2050. Low-conflict solar energy from rooftops could contribute approximately 30% of the required 22–25 TWh/yr. Intensified wood production and wind energy could add another 40%. The gap of approximately 30% must come from undisputed energy sources such as biogas from recycled organic material, from centralized renewable energies such as geothermal or large hydropower, or from new or technologically improved renewable energies. The presented decision support tools are a timely contribution to the designation of legally binding zones for renewable energy production. [ABSTRACT FROM AUTHOR]