Browsing by Issue Date, starting with "2023-01"
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- Risk-Sharing Contracts and risk management of bilateral contracting in electricity marketsPublication . Algarvio, HugoABSTRACT: The liberalization of the electricity sector has conducted to the establishment of spot markets, derivative markets and private bilateral contracts to trade electricity, increasing the competition in the sector. Spot markets are composed of day-ahead, intraday and real-time markets, and their prices are highly volatile. Derivative markets are composed of physical and financial products to hedge against spot price volatility. Players can set the terms and conditions of private bilateral contracts but these have several risks that can be mitigated using a risk management process composed of three phases: risk assessment, characterization and hedging. This paper focuses on both risk attitude and risk-sharing, and how they can influence the negotiation of the price. It presents the standard and non-standard designs of a new type of contract, the Risk-Sharing Contract (RSC). Furthermore, it describes the trading process of these contracts and introduces a negotiation strategy for dealing with risk. It also presents case studies on bilateral contracting involving the negotiation of RSCs, where different demand and supply agents interact and trade according to the rules of an alternating offers protocol. Results from the case studies prove the benefit of RSCs to hedging against spot price volatility, benefiting risk-averse players by reducing the price risk and conducting mutually beneficial agreements. While the use of derivatives products can conduct losses/revenues between -15% and 3% concerning the spot market, by using non-standard RSCs those outputs vary between -1% and 3% with substantially less risk.
- Landslide monitoring techniques in the Geological Surveys of EuropePublication . Auflič, Mateja Jemec; Herrera, Gerardo; Mateos, Rosa María; Poyiadji, Eleftheria; Quental, Lídia; Severine, Bernardie; Peternel, Tina; Podolszki, Laszlo; Calcaterra, Stefano; Kociu, Arben; Warmuz, Bartłomiej; Jelének, Jan; Hadjicharalambous, Kleopas; Becher, Gustaf Peterson; Dashwood, Claire; Ondrus, Peter; Minkevičius, Vytautas; Todorović, Saša; Møller, Jens Jørgen; Marturia, JordiABSTRACT: Landslide monitoring is a mandatory step in landslide risk assessment. It requires collecting data on landslide conditions (e.g., areal extent, landslide kinematics, surface topography, hydrogeometeorological parameters, and failure surfaces) from different time periods and at different scales, from site-specific to local, regional, and national, to assess landslide activity. In this analysis, we collected information on landslide monitoring techniques from 17 members of the Earth Observation and Geohazards Expert Group (from EuroGeoSurveys) deployed between 2005 and 2021. We examined the types of the 75 recorded landslides, the landslide techniques, spatial resolution, temporal resolution, status of the technique (operational, non-operational), time of using (before the event, during the event, after the event), and the applicability of the technique in early warning systems. The research does not indicate the accuracy of each technique but, rather, the extent to which Geological Surveys conduct landslide monitoring and the predominant techniques used. Among the types of landslides, earth slides predominate and are mostly monitored by geological and engineering geological mapping. The results showed that Geological Surveys mostly utilized more traditional monitoring techniques since they have a broad mandate to collect geological data. In addition, this paper provides new insights into the role of the Geological Surveys on landslide monitoring in Europe and contributes to landslide risk reduction initiatives and commitments (e.g., the Kyoto Landslide Commitment 2020).
- Economia de recursos e comunidades de energiaPublication . Sousa Rocha, Cristina; Trindade, Paula; Simoes, SofiaRESUMO: A eletricidade renovável é imprescindível para melhorar a qualidade do ar, para a descarbonização e o combate às alterações climáticas - um dos maiores desafios com que a Humanidade se defronta. Neste quadro, as comunidades de energia têm um papel fundamental a desempenhar, contribuíndo para a instalação e consumo eficientes de energia (renovável).
- The Use of Oleaginous Yeasts and Microalgae Grown in Brewery Wastewater for Lipid Production and Nutrient Removal: A ReviewPublication . Dias, Carla; Santos, José A. L.; Reis, Alberto; Silva, Teresa Lopes daABSTRACT: Brewery wastewater has been proposed as an attractive low-cost substrate for microbial lipid production for oleaginous yeast and microalga with promising results. For each liter of beer produced, from 3 to 10 L of wastewater are generated which can be used as culture medium for autotrophic or heterotrophic metabolism. This strategy allows reducing the culture medium cost, as well as obtaining high lipid contents and other high value compounds which can make the process profitable. Additionally, the use of industrial effluents/wastes as substrates for microbial growth can be a strategy to treat them based on the circular economy rules. This review presents the different brewery wastewater treatment strategies using oleaginous yeast and microalga pure and mixed cultures for the concomitant wastewater treatment and lipids/carotenoids production so far reported, highlighting the benefits/disadvantages of such strategies and comparing their performance in terms of wastewater treatment, lipids and carotenoids production between pure and mixed cultures performance.
- Cistus ladanifer as a Potential Feedstock for Biorefineries: A ReviewPublication . Alves Ferreira Caturra, Júnia Aparecida; Duarte, Luís C.; Fernandes, M. C.; Pereira, Helena; Carvalheiro, FlorbelaABSTRACT: Cistus ladanifer (rockrose) is a widespread shrub species in the Mediterranean region well known due to its production of labdanum gum, especially in the hot season. Its leaves and branches can be subjected to different extraction and distillation processes to produce various types of extracts. The natural extracts of C. ladanifer have several applications, especially in the perfumery and cosmetics sector. C. ladanifer extracts, in addition to presenting interesting odoriferous properties, are also known for their bioactive properties, such as antioxidant and antimicrobial. Use of this species in animal feed or phytostabilisation of mining areas has also been successfully applied. On the other hand, the lignin and polysaccharides that are the major fractions from Cistus residues can be relevant sources of high-value products in a biorefinery framework. Recently, it has been reported that the residues obtained from the essential oil industry can sustain production of significant amounts of other marketable products, namely phenolic compounds, oligomeric and monomeric sugars, lignin, and lactic acid. All these applications show the potential of C. ladanifer as a raw material to be fully valued in a biorefinery context, contributing to important revenues and generating an associated marketable biobased product portfolio.
- Bilateral Contracting and Price-Based Demand Response in Multi-Agent Electricity Markets: A Study on Time-of-Use TariffsPublication . Algarvio, Hugo; Lopes, FernandoABSTRACT: Electrical energy can be traded in liberalized organized markets or by negotiating private bilateral contracts. Competitive markets are central systems where market players can purchase and sell electrical energy. Bilateral contracting consists typically in a private negotiation of power over several months or years between two parties. Price-based demand response considers the active participation of consumers in electricity markets. Consumers adopt demand response programs when responding to market prices or tariffs, as they change over time. Those tariffs can be proposed by retailers by considering their load shape goals, influencing consumers to change their behavior. Consumers may adopt strategies from two different groups, namely by curtailing energy at times of high prices (e.g., peak and intermediate periods) and rescheduling energy away from those times to other times (shifting). This article considers bilateral contracting in electricity markets with demand response. It investigates how curtailment and shifting affect the energy quantity and energy cost of consumers that adopt a time-of-use tariff involving three block periods (i.e., base, intermediate and peak periods). The results indicate that consumers respond to changes in energy price according to their consumption flexibility, while retailers do not always change energy price in response to consumers' efforts to change their consumption patterns. On average, by considering a 5% consumption reduction in the intermediate and peak periods by a consumer agent, a retailer agent reduces the energy price only by 1.5%.
- Identificação de áreas com menor sensibilidade ambiental e patrimonial para localização de unidades de produção de eletricidade renovávelPublication . Simoes, Sofia; Quental, Lídia; Simões, Teresa; Catarino, Justina; Rodrigues, Carlos; Patinha, Pedro; Pinto, P.J.R.; Azevedo, Pedro; Picado, Ana; Cardoso, João P.; Barbosa, Juliana; Oliveira, PaulaRESUMO: Este documento descreve o trabalho desenvolvido pelo LNEG com vista à futura identificação de “Go-To Areas” para a localização de unidades de produção de energia de fonte renovável em Portugal Continental. O trabalho decorreu no âmbito de um Grupo de Trabalho informal, coordenado pelo LNEG e envolvendo as seguintes entidades: a Agência Portuguesa do Ambiente (APA), a Direção Geral de Energia e Geologia (DGEG), a Direção Geral do Território (DGT), o Instituto da Conservação da Natureza e das Florestas (ICNF) e a Direção-Geral do Património Cultural (DGPC). Neste âmbito, pretendeu-se identificar no país as áreas com menor sensibilidade (ambiental e patrimonial) que possam vir a ser elegíveis para um processo de licenciamento mais simplificado para unidades de produção de energia de fonte renovável solar e eólica, permitindo deste modo acelerar a implementação sem comprometer outros valores ambientais e territoriais. As áreas resultantes serão áreas preferenciais do ponto de vista de simplificação do processo de licenciamento, mas não são exclusivas. Ou seja, as áreas aqui identificadas e as futuras “Go-To Areas” que possam vir a surgir não representam os únicos locais do país onde é possível implementar unidades renováveis. No resto do território a implementação é possível, de acordo com o normal processo de licenciamento. Este trabalho não delimita “Go-To Areas” renovável. Trata-se de um documento técnico que apresenta áreas sem condicionantes de exclusão que podem vir a ser consideradas para a definição formal de “Go-To Areas”. Deve notar-se que os resultados apresentados traduzem a situação à data de novembro / dezembro 2022, sendo que muita da informação utilizada tem um caráter dinâmico pelo que este trabalho deverá ser atualizado periodicamente.Este documento é complementado com vários ficheiros eletrónicos do Sistema de Informação Geográfica (SIG) contendo os dados de suporte produzidos/compilados. Por fim e não menos importante, este primeiro trabalho foca exclusivamente as áreas não artificializadas. Embora seja fundamental para o país a implementação de renováveis de forma distribuída em ambiente construído/artificializado, a análise desse universo necessita de mais tempo e recursos do que os disponíveis neste âmbito.
- Thermal decomposition of δ-MoN and ε-Fe2N synthesized under concentrated solar radiation in NH3 gas streamPublication . Cañadas, Inmaculada; Oliveira, Fernando Almeida Costa; Rodriguez, Jose; Shohoji, NobumitsuABSTRACT: Decomposition temperatures of δ-MoN and ε-Fe2N synthesized with flowing NH3 gas under concentrated solar radiation heating were evaluated by Differential Scanning Calorimetry (DSC) in Argon (Ar) gas environment. The measured decomposition temperature of δ-MoN and ε-Fe2N were dependent on the solar synthesis conditions, particularly either NH3 or N2 gas flow rate at temperature. Sample containing δ-MoN showed two exothermic peaks around 680 and 900 ◦C, attributed to the reactions of δ-phase into γ-single-phase and (γ+β)-two-phase Mo2N, respectively, attributed to the dissociation reaction of δ-phase into γ-single phase and the dissociation reaction of γ-phase into metallic M saturated with N, respectively. Decomposition of ε-Fe2N took place into γ’-Fe4N in two steps occurring at 606 and 660 ◦C, respectively. When N2 instead of ammonia (NH3) gas was used, complete dissociation of γ’-Fe4N into Fe took place at around 610 ◦C. Full decomposition of γ’-Fe4N into metallic α-Fe(N) was corroborated by X-ray diffraction (XRD) analysis.