http://hdl.handle.net/11531/4153 WorkingPaper, ponencias invitadas y contribuciones en congresos no publicadas Wed, 20 May 2026 09:07:40 GMT 2026-05-20T09:07:40Z http://hdl.handle.net/11531/110166 Sensor de nivel de líquidos en recipientes opacos basado en resonadores con acoplamiento magnetoinductivo axial Herraiz Martínez, Francisco Javier; Alonso Rivas, Eduardo; Muñoz Frías, José Daniel; Giannetti, Romano En esta comunicación se presenta un sensor de microondas de bajo coste para la detección de nivel de líquidos en recipientes dieléctricos opacos, con especial atención al aceite de oliva. El sistema propuesto se basa en un resonador Square Split-Ring Resonator (SSRR) situado en el interior del recipiente, cuya resonancia varía en función de si está cubierto por el líquido o no. La interrogación se realiza sin contacto mediante acoplamiento axial por ondas magnetoinductivas (MIW) con un SSRR externo acoplado a su vez a una línea de transmisión microstrip. El sistema opera a 2,45 GHz y emplea un esquema de detección en amplitud mediante un oscilador a frecuencia fija y un detector basado en diodo Schottky, lo que permite una implementación de bajo coste. Las simulaciones electromagnéticas muestran una clara diferencia entre las condiciones de vacío y cubierto con aceite, con niveles de transmisión de −1,84 dB y −9 dB a 2,45 GHz, respectivamente, lo que se traduce en tensiones de salida de 244 mV y 81 mV. Estos resultados demuestran la viabilidad de la propuesta para la detección binaria en tiempo real del nivel de líquido en recipientes opacos.; http://hdl.handle.net/11531/110166 http://hdl.handle.net/11531/110085 When flexibility signals interact: Quantifying the interplay of mechanisms for acquiring DSO services Ormeño Mejía, Eliana Carolina; Chaves Ávila, José Pablo; Troncia, Matteo ; The growing incorporation of distributed energy resources (DERs), together with the electrification of transport, heating and cooling, is making distribution networks more dynamic and more exposed to local congestion and voltage problems. In this context, system operators are considering a range of flexibility acquisition mechanisms, including network tariffs, local flexibility markets (LFMs), and flexible connection agreements (FCAs), to address these network challenges. However, these mechanisms are often designed independently, even though they can coexist and act on the same customers. Depending on their design and how their signals interact, these acquisition mechanisms may reinforce each other, enabling more effective customer responses to meet network requirements, or, conversely, lead to redundant or conflicting signals that undermine their joint efficiency.Thus, this work presents a based-model assessment, developed within the BeFlexible project, to analyse how multiple mechanisms for acquiring flexibility interact when implemented jointly in distribution networks with high shares of DERs and flexible demand. The study examines how price signals from network tariffs, local flexibility markets, and flexible connection agreements jointly influence the behaviour of flexible loads, such as electric vehicles (EVs), heat pumps (HPs), and water heaters (WHs), and how these responses translate into network impacts. Four case studies are considered to assess: (i) the interaction between network tariff designs (national and local) and LFMs; (ii) the role of temperature-driven demand variation under these acquisition mechanisms and network impacts; (iii) the effect of changes in regulated tariff components; and (iv) the interplay between FCAs, network tariffs, and LFMs.The results show that predictable system-wide tariff signals may synchronise flexible demand and unintentionally create local congestion, particularly for highly price-responsive resources. LFMs improve congestion management by introducing locational corrective signals, while ex-post local tariffs help reduce excessive predictability, gaming opportunities, and local market power concentration. Flexible connection agreements further complement tariff- and market-based mechanisms by limiting coincident demand during constrained hours. Overall, the findings highlight that a coordinated acquisition mechanism design is essential to align incentives with local grid constraints, reduce inefficient or conflicting signals, and support the secure and cost-effective operation of active distribution networks. http://hdl.handle.net/11531/110085 http://hdl.handle.net/11531/109949 Asymptotic analysis of the thermal interaction of geothermal boreholes with aquifers valid for all groundwater flow regimes Rico Cabrera, Javier; Hermanns, Miguel ; Heating and cooling needs of buildings represent a significant share of the world’s total energy consumption. To reach a more sustainable energy future, it is crucial to enhance the efficiency of heating, ventilation and air conditioning (HVAC) systems. Reducing energy demand in buildings contributes not only to the preservation of limited natural resources but also to the mitigation of greenhouse gas emissions and other environmental impacts. Among the available technologies, HVAC systems that harness low-temperature geothermal energy are among the most promising solutions to achieve such reductions. [...] http://hdl.handle.net/11531/109949 http://hdl.handle.net/11531/109931 Electricity System Service Costs on the Rise: Is Spain’s Cost Allocation Mechanism Still Fit for Purpose? Avello Gorostidi, Pedro; Chaves Ávila, José Pablo ; System service costs in Spain have increased by more than 400% since 2020, reaching 16.5% of wholesale market value in 2024. These costs are recovered through a uniform volumetric charge on demand, despite being largely non-marginal or location-specific. This paper assesses the efficiency implications of this allocation mechanism and quantifies associated welfare losses using empirical aggregate supply and demand curves from the Spanish day-ahead market. Results show growing distortions, although small in size relative to wholesale market volumes. However, the distortion is expected to grow, particularly as demand elasticity increases. The paper concludes that volumetric recovery is no longer fit for purpose and proposes alternative mechanisms based on network tariffs and imbalance-linked allocation. http://hdl.handle.net/11531/109931