Browsing by Keyword "General Energy"
Now showing 1 - 20 of 33
Results Per Page
Sort Options
Item Calibration procedures for multidimensional heat transfer models based on on-site experimental data(2015-11-01) Garay, Roberto; Uriarte, Amaia; Apraiz, Inés; Martinez, Roberto Garay; Arrien, Amaia Uriarte; Egaña, Ines Apraiz; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAAn experimental and numerical approach to the characterization of thermal bridges is presented, based on on-site taken measurements. Commonly on-site applied numerical thermal assessments perform one-dimensional heat transfer analysis over planar elements such as facades. However, it is well known that within thermal bridges in a building one-dimensional heat transfer analysis cannot be applied. A procedure is proposed, based on the creation of a numerical 2D thermal model which is calibrated against experimental data from several temperature and heat flux sensors which are located at specific points in the thermal bridge elements. Results of one particular implementation of this method are discussed.Item Curtain Wall with Solar Preheating of Ventilation Air. Full Scale Experimental Assessment(2020-06-30) Garay-Martinez, Roberto; Arregi, Beñat; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAHeating load in Commercial buildings is highly related with ventilation systems, while at the same time local discomfort in the vicinity of glass walls occurs due to overheating. In this paper, a novel double envelope curtain wall is presented, which extracts heat from the façade by means of a ventilated cavity which is then incorporated to the ventilation air intake. A substantial reduction of heating loads is achieved. Whenever solar gains are not sought, a bypass element allows the natural ventilation of this air cavity, acting as a ventilated façade. An integrated control system with embedded electronics and actuators allows for a smart control of the system. The system is designed for integration with existing rooftop ventilation systems. Design considerations are discussed, and the outcomes of a full-scale experiment conducted in Bilbao (Spain) along 2019 presented.Item Data driven model for heat load prediction in buildings connected to District Heating by using smart heat meters(2022-01-15) Lumbreras, Mikel; Garay-Martinez, Roberto; Arregi, Beñat; Martin-Escudero, Koldobika; Diarce, Gonzalo; Raud, Margus; Hagu, Indrek; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAAn accurate characterization and prediction of heat loads in buildings connected to a District Heating (DH) network is crucial for the effective operation of these systems. The high variability of the heat production process of DH networks with low supply temperatures and derived from the incorporation of different heat sources increases the need for heat demand prediction models. This paper presents a novel data-driven model for the characterization and prediction of heating demand in buildings connected to a DH network. This model is built on the so-called Q-algorithm and fed with real data from 42 smart energy meters located in 42 buildings connected to the DH in Tartu (Estonia). These meters deliver heat consumption data with a 1-h frequency. Heat load profiles are analysed, and a model based on supervised clustering methods in combination with multiple variable regression is proposed. The model makes use of four climatic variables, including outdoor ambient temperature, global solar radiation and wind speed and direction, combined with time factors and data from smart meters. The model is designed for deployment over large sets of the building stock, and thus aims to forecast heat load regardless of the construction characteristics or final use of the building. The low computational cost required by this algorithm enables its integration into machines with no special requirements due to the equations governing the model. The data-driven model is evaluated both statistically and from an engineering or energetic point of view. R2 values from 0.70 to 0.99 are obtained for daily data resolution and R2 values up to 0.95 for hourly data resolution. Hourly results are very promising for more than 90% of the buildings under study.Item Data driven process for the energy assessment of building envelope retrofits(2020-06-30) Garay-Martinez, Roberto; Arregi, Beñat; Lumbreras, Mikel; Zurro, Belén; Gonzalez, Jose Manuel; Hernandez, Jose Luis; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAIn the last decades, a growing industry has been created in relation to building envelope retrofits. Linked to the lack of financial capacity of many building owners, innovative instruments such as energy performance contracts have been promoted by public bodies. This kind of instruments require of detailed energy assessment processes in order to define the expected heat load reduction and the associated economic flows between building owners and Energy Services Companies. When dealing with building envelopes, existing methods for building envelope heat loss characterization require of substantial efforts in terms of equipment and time, which makes them difficult to apply in real practice. In this paper, a novel method is proposed based on whole-building heat load assessment by means of heat meters, and analytical calculations of building envelope transmission heat load coefficients. This method, which requires minimal or no additional equipment, can be used over historical data from District Heating systems. It assigns a specific load fraction to building envelope heat transfer and allows to assess the expected reduction due to the building envelope retrofit. Numerical and experimental data is presented based on an educational building in the city of Burgos, Spain.Item Data-driven assessment for the supervision of District Heating Networks(2022-12) Eguiarte, Olaia; Garrido-Marijuan, Antonio; Garay-Martinez, Roberto; Raud, Margus; Hagu, Indrek; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAThere is an ongoing trend towards temperature reduction in District Heating Networks, allowing for the reduction of distribution heat loss and enabling the integration of low exergy heat production systems. There is a clear scientific consensus on the improved sustainability of such systems. However, there is not sufficient knowledge on how to deliver a successful transition to a low temperature District Heating system, while ensuring the operational levels of the existing system. This paper presents the experience on the progressive temperature reduction of a district heating subnetwork over the 2018–2021 period in Tartu, Estonia. Data from heat meters is extensively used to assess the capacity of substations and network branches to deliver the required heat and quality levels. Faulty substations are identified for targeted assessment and improvement works. Several substations have been identified as missing some of the performance criteria. This has led to further analysis, closer supervision and interventions in the operational conditions of the network. This is an ongoing process, expected to remain in the established procedures of the DH network operator. At the end of the process, a temperature reduction of 7 ºC has shown an improvement of 4.8% in network heat loss.Item Design of a Calorimetric Test Facility to Replicate Real Boundary Conditions in the Gulf Countries(2020-06-30) Garay-Martinez, Roberto; Jayan, Bejay; Arregi, Beñat; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAThe design and modelling of a calorimetric test infrastructure for building envelopes is performed for the side-by-side assessment of different building envelope systems. The infrastructure is designed for representing transient weather conditions in Middle east. It consists of 3 “cold” experimental chambers and a larger “hot” experimental chamber. All three cold chambers have one equally sized envelope element exposed to the larger chamber. The test facility is designed to allow testing on walls and roofs, where different envelope insulation systems will be installed over a common substrate. Heating and cooling loads of all experimental chambers are calculated, and systematic load differences assessed. Heat flow across test samples and other surfaces in the test are calculated. Insulation levels of envelope surfaces in experimental chambers are specified to provide a good match between heat transfer across test samples and heat input to experimental chambers.Item Direct route from ethanol to pure hydrogen through autothermal reforming in a membrane reactor: Experimental demonstration, reactor modelling and design: Experimental demonstration, reactor modelling and design(2018-01-15) Spallina, V.; Matturro, G.; Ruocco, C.; Meloni, E.; Palma, V.; Fernández-Gesalaga, E.; Melendez, J.; Pacheco Tanaka, David A.; Viviente Sole, J.L.; van Sint Annaland, M.; Gallucci, F.; Tecnalia Research & Innovation; TECNOLOGÍAS DE HIDRÓGENO; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThis work reports the integration of thin (∼3–4 μm thick) Pd-based membranes for H2 separation in a fluidized bed catalytic reactor for ethanol auto-thermal reforming. The performance of a fluidized bed membrane reactor has been investigated from an experimental and numerical point of view. The demonstration of the technology has been carried out over 50 h under reactive conditions using 5 thin Pd-based alumina-supported membranes and a 3 wt%Pt-10 wt%Ni catalyst deposited on a mixed CeO2/SiO2 support. The results have confirmed the feasibility of the concept, in particular the capacity to reach a hydrogen recovery factor up to 70%, while the operation at different fluidization regimes, oxygen-to-ethanol and steam-to-ethanol ratios, feed pressures and reactor temperatures have been studied. The most critical part of the system is the sealing of the membranes, where most of the gas leakage was detected. A fluidized bed membrane reactor model for ethanol reforming has been developed and validated with the obtained experimental results. The model has been subsequently used to design a small reactor unit for domestic use, showing that 0.45 m2 membrane area is needed to produce the amount of H2 required for a 5 kWe PEM fuel-cell based micro-CHP system.Item Domestic space heating dynamic costs under different technologies and energy tariffs: Case study in Spain: Case study in Spain(2020-12) Eguiarte, O.; de Agustín-Camacho, P.; Garrido-Marijuán, A.; Romero-Amorrortu, A.; EDIFICACIÓN DE ENERGÍA POSITIVA; LABORATORIO DE TRANSFORMACIÓN URBANADynamic energy tariffs facilitate engaging domestic consumers on demand management, contributing to grid’s stability, but requires of informed decision enabling tools. This paper presents a domestic heating costs calculation method for different heating technologies (gas boiler, heat-pumps) and a range of energy tariffs. Based on physical modeling, effect of outdoor temperature in the COP of heat-pumps is assessed. The methodology is applied to the 2018/19 heating season in Madrid (Spain), calculating the heating costs under four diverse energy tariffs (static gas tariff, static electricity tariff, real-time-price electricity tariff, dynamic time-of-use electricity tariff) for a typical home demand. The hourly results for two representative days are detailed, along with the aggregated results for the whole season. Along the season, the continuous changes in energy wholesale market prices and weather conditions make one heating technology and/or tariff more convenient each time. For the whole season, the dynamic time-of-use tariff considered would imply heating costs up to 40% lower than the static gas tariff. The results are strongly conditioned by climate conditions and national energy market evolutions. Day-ahead information on the actual heating costs might lead to domestic end-users to adapt their behavior and consumption patterns for more cost-effective use of the energy.Item Encapsulated high temperature PCM as active filler material in a thermocline-based thermal storage system(2015-05-01) Muñoz-Sánchez, B.; Iparraguirre-Torres, Iñigo; Madina, Virginia; Izagirre, Usoa; Unzurrunzaga-Iturbe, A.; García-Romero, A.; Madina-Arrese, V.; Izagirre-Etxeberria, U.; Tecnalia Research & Innovation; MATERIALES PARA CONDICIONES EXTREMAS; INGENIERÍA DE SUPERFICIES; VALORIZACIÓN DE RESIDUOSA great concern in Concentrated Solar Power (CSP) is to boost energy harvesting systems, by finding materials with enhanced thermal performance. Phase Change Materials (PCM) have emerged as a promising option, due to their high thermal storage density compared to sensible storage materials currently used in CSP. A thermal storage system for solar power plants is proposed, a thermocline tank with PCM capsules together with filler materials, based on multi-layered solid-PCM (MLSPCM) thermocline-like storage tank concept [1,2]. A detailed selection of the most suitable high temperature PCM, their containment materials and encapsulation methods are shown.Item Energy and economic analysis of domestic heating costs based on distributed energy resources: A case study in Spain: A case study in Spain(2022-12) Eguiarte, Olaia; de Agustín-Camacho, Pablo; del Portillo-Valdés, Luis; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVA; LABORATORIO DE TRANSFORMACIÓN URBANAEnergy electrification is part of the European strategy for the decarbonization of the building sector and energy transition in cities. The present paper compares the heating costs of covering the heating demand by different systems: (i) domestic gas boiler and an air-to-air heat-pump, (ii) without and (iii) with local PV backup; in order to analyze the effects of the electric price volatility along with the weather condition dependency of the renewable systems. The study presents a heat pump model and a PV generation model to estimate the hourly performance of both systems. These models are then applied in an average dwelling in Bilbao, Spain, in November 2020, and November 2021. Results show that in November 2020 the combined use of a heat pump with PV generation to cover the heat demand was 66% cheaper than covering the same demand with a natural gas boiler. By contrast, the combined use of the PV and heat pump resulted in a 15% higher energy bill compared to the natural gas in 2021 due to the increase of the electricity prices (3 times higher), the lower temperatures (25%) and less solar radiation (70%).Item Energy demand prediction for the implementation of an energy tariff emulator to trigger demand response in buildings(2019-08-13) Noyé, Sarah; Saralegui, Unai; Rey, Raphael; Anton, Miguel Angel; Romero, Ander; Tecnalia Research & Innovation; DIGITALIZACIÓN Y AUTOMATIZACIÓN DE LA CONSTRUCCIÓN; EDIFICACIÓN DE ENERGÍA POSITIVABuildings are key actors of the electrical gird. As such they have an important role to play in grid stabilization, especially in a context where renewable energies are mandated to become an increasingly important part of the energy mix. Demand response provides a mechanism to reduce or displace electrical demand to better match electrical production. Buildings can be a pool of flexibility for the grid to operate more efficiently. One of the ways to obtain flexibility from building managers and building users is the introduction of variable energy prices which evolve depending on the expected load and energy generation. In the proposed scenario, the wholesale energy price of electricity, a load prediction, and the elasticity of consumers are used by an energy tariff emulator to predict prices to trigger end user flexibility. In this paper, a cluster analysis to classify users is performed and an aggregated energy prediction is realised using Random Forest machine learning algorithm.Item Energy efficiency achievements in 5 years through experimental research in KUBIK(2015-06) Garay, Roberto; Chica, José Antonio; Apraiz, Inés; Campos, José María; Tellado, Borja; Uriarte, Amaia; Sánchez, V.; Tecnalia Research & Innovation; SG; DIGITAL ENERGY; EDIFICACIÓN DE ENERGÍA POSITIVAThe European construction sector (a fragmented SMEs dominated business with high economic and environmental impact and high technological inertia) faces a major challenge to reduce the emissions by almost 90% in 2050. This requires new innovative solutions and services to be rapidly implemented in the market. Research Infrastructures that give support for later-stage developments (high Technology Readiness Levels) can play a relevant role in both the technological development and market introduction of construction products for energy efficient buildings. The following paper describes such an infrastructure (KUBIKby (Tecnalia)) located in Bilbao (Spain) and its major outcomes in the period 2011-2015.Item Engaging domestic users on demand response for heating cost reduction with a recommendation tool: Case study in Belgrade: Case study in Belgrade(2022-06) Eguiarte, O.; de Agustín-Camacho, P.; Garrido-Marijuan, A.; Vukovic, M.; del Portillo, L.; Romero-Amorrortu, A.; EDIFICACIÓN DE ENERGÍA POSITIVA; LABORATORIO DE TRANSFORMACIÓN URBANAThe European Union has established a legislative framework that aims to enable consumers and businesses to take information-based decisions to save energy and money. Additionally, the increase of Distributed Energy Resources (both on generation and consumption) requires additional efforts to maintain the reliability and stability of the electric grid and the need of flexibility from residential buildings. The present study introduces a domestic decision support tool for reducing heating costs. This app provides detailed recommendations to end-users based on the day-ahead hourly weather forecast, electric and district heating tariffs predictions, heating demand, and heating systems dynamic performance. The tool was tested in 6 dwellings of a neighborhood of Belgrade during the last months of 2021 heating season (March–May). Energetic results suggest that 40% of participants followed the given recommendations and changed their heating pattern. Additionally, survey results show that end-users found the lack of information and knowledge as the main barrier to actively participate in the energy market, also preferring to have automatic control in their heating system. Authors conclude that recommendation tools are key elements in user-engagement, but they should be supported by additional information and training.Item Experimentation under real performing conditions of a highly integrable unglazed solar collector into a building façade(2017-09) Elguezabal, P.; Garay, Roberto; Martin, K.; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓN; Tecnalia Research & InnovationIn the current context of moving towards more sustainable construction, advanced façade systems that integrate solar collecting devices represent a commitment with future trends that combine renewable technologies with building skins. This paper describes a real experience when combining a novel unglazed solar collector based on sandwich panel technology, a heat pump and a controller that manages the different operation modes. Installed in the Kubik by Tecnalia testing building in northern Spain, the system has been monitored for several months in 2016, under an energy efficiency scope. The study will present measured values regarding the yield of the collector, performance of the heat pump and general efficiencies.Item Full scale experimental performance assessment of a prefabricated timber panel for the energy retrofitting of multi-rise buildings(2017-09) Garay, Roberto; Benito Ayucar, Josu; Arregi Goikolea, Beñat; Garay Martinez, Roberto; Tecnalia Research & Innovation; Materiales Construcción Azpeitia; EDIFICACIÓN DE ENERGÍA POSITIVAA prefabricated timber façade system is presented for the energy retrofitting of buildings. Large panel dimensions facilitate the installation of this system, with reduced disturbance to building users and increased overall quality in terms of thermal bridge mitigation and air tightness of architectural junctions. A full scale proof of concept test is performed, where several prefabricated timber panels were installed over a pre-existing brick façade, their junctions tested, and the differential thermal performance of the system is evaluated. It is concluded that the overall thermal performance of the system is satisfactory in terms of overall U-value, thermal bridge coefficient and, temperature factor. Furthermore, and based on experimentally obtained data, a dynamic characterization of the harmonic thermal response of the system is performed.Item A high-temperature heat pump for compressed heat energy storage applications: Design, modeling, and performance: Design, modeling, and performance(2022-11) Hassan, Abdelrahman H.; Corberán, José M.; Ramirez, Miguel; Trebilcock-Kelly, Felipe; Payá, Jorge; Tecnalia Research & Innovation; SISTEMAS TÉRMICOS EFICIENTESThe current paper presents the design and performance of a high-temperature heat pump (HTHP) integrated in an innovative, sensible, and latent heat storage system. The HTHP has been designed to work between a heat source from 40 to 100 °C and a heat sink above 130 °C. An initial refrigerant analysis has revealed that R-1233zd(E) is the best candidate to meet the required performance and environmental considerations. The first part of this paper deals with the sizing and selection of the main components while discussing the challenges and working limits. A numerical model is also presented and validated. The second part of the paper is dedicated to develop parametric studies and performance maps under different operating conditions. The results show that the current HTHP, at a source temperature of 80 °C, consumes from 3.23 to 9.88 kW by varying the compressor’s speed from 500 to 1500 rpm. Heat production is achieved in the form of latent heat (7.40 to 21.59 kW) and sensible heat (from 6.35 to 17.94 kW). The heating coefficient of performance (COPHTHP) is around 4.Item Influence of climate change externalities on the sustainability-oriented prioritisation of prospective energy scenarios(2020-04-01) Iribarren, Diego; Martín-Gamboa, Mario; Navas-Anguita, Zaira; García-Gusano, Diego; Dufour, Javier; Tecnalia Research & Innovation; PLANIFICACIÓN ENERGÉTICAThe implementation of externalities in energy policies is a potential measure for sustainability-oriented energy planning. Furthermore, decisions on energy policies and plans should be based on the analysis of a number of potential energy scenarios, considering the evolution of key techno-economic and life-cycle sustainability indicators. The joint interpretation of these multiple criteria should drive the choice of appropriate decisions for energy planning. Within this context, this work proposes –for the first time– the combined use of Life Cycle Assessment, externalities calculation, Energy Systems Modelling and dynamic Data Envelopment Analysis to prioritise prospective energy scenarios. For demonstration and illustrative purposes, the application of this methodological framework to the case study of electricity production in Spain leads to quantitatively discriminate between 15 prospective energy scenarios by taking into account the life-cycle profile of the transformation path of the power generation system with time horizon 2050. When compared to the application of the framework without implementation of external costs, the internalisation of climate change externalities is found to affect the ranking of energy scenarios but still showing the rejection of those scenarios based on the lifetime extension of coal power plants, as well as the preference for those scenarios leading to a high penetration of renewable technologies.Item Innovative pre-fabricated components including different waste construction materials reducing building energy and minimising environmental impacts (InnoWEE)(2019-08-13) Fodor, Loredana; Ducman, Vilma; Ferrarini, Giovanni; Tamburini, Sergio; Tsoutis, Constantinos; Becherini, Francesca; Garrido-Marijuán, Antonio; Mezzasalma, Giulia; Rossi, Leonardo; Lezak, Emil; Bernardi, Adriana; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAInnoWEE is a four-year project (from 2016 to 2020) financed by the European Community that involves ten partners from different European countries, as Greece, Italy, Belgium, Romania, Slovenia, Spain and Poland. The aim is to use the waste materials coming from construction and demolition processes of buildings and include them into a geopolymeric matrix with the purpose of producing prefabricated panels for different applications. Construction and demolition waste (CDW) materials with suitable characteristics have been selected to develop high performance geopolymeric panels for building walls envelopes and radiant panels for indoor walls and ceilings with low environmental impact. Field tests will be carried out in different sites in Europe characterized by different climatic conditions to check the simplicity of the installation procedure and the performance of the panels in terms of energy efficiency and environmental impact.Item Interconnection between scales for friendly and affordable sustainable urban districts retrofitting(2015-11-01) Barbano, Giulia; Egusquiza, Aitziber; LABORATORIO DE TRANSFORMACIÓN URBANAThe EU FP7 project FASUDIR (Friendly and Affordable Sustainable Urban Districts Retrofitting) supports the mobilization of the building retrofitting market towards 2020-2050 EU-targets through an Integrated Decision Support Tool (IDST), a software based on a new methodology that will help decision makers identify the best energy retrofitting strategy to increase the sustainability of the whole district. Improving the sustainability of urban environments is a interscalar problem, addressed through a multiscalar and multidirectional approach. A comprehensive urban scale strategy considers the working scale, but the measures at building scale have to be coherent with the global objectives at district and city scale. The FASUDIR IDST and methodology interconnect and visualize information across scales, ensuring comprehensive diagnoses and proper implementation of strategies. Due to the complexity of urban sustainability, interscalarity and multiscalarity, first it has been necessary to identify the possible scales of analysis, to capture various themes and to highlight the horizontal and vertical interconnections between different components. Multiscalarity and Interscalarity affect the three phases of the sustainable retrofitting cycle: diagnosis, decision making and management. The identification of the impact of district solutions on buildings (and vice versa) and their compatibility across scales has been addressed through interconnected building and district Key Performance Iindicators (KPIs). The intervention phases at building level generate new information about specific buildings, enabling more accurate decision making at district level. The methodology articulates the structure of the new information and the feedback generated during the process. To allow information interconnection a strategic information management is key. A multiscale information model based on CityGML, a standard data model issued by the OGC (Open Geospatial Consortium), will be the baseline structure for all the district-scale information (geometric and semantic) that is necessary for decision making and management, organized into a single interoperable data model that will integrate information from different fields and at different levels of detail.Item The membrane-assisted chemical looping reforming concept for efficient H2 production with inherent CO2 capture: Experimental demonstration and model validation: Experimental demonstration and model validation(2018-04-01) Medrano, J.A.; Potdar, I.; Melendez, J.; Spallina, V.; Pacheco Tanaka, David A.; van Sint Annaland, M.; Gallucci, F.; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSIn this work a novel reactor concept referred to as Membrane-Assisted Chemical Looping Reforming (MA-CLR) has been demonstrated at lab scale under different operating conditions for a total working time of about 100 h. This reactor combines the advantages of Chemical Looping, such as CO2 capture and good thermal integration, with membrane technology for a better process integration and direct product separation in a single unit, which in its turn leads to increased efficiencies and important benefits compared to conventional technologies for H2 production. The effect of different operating conditions (i.e. temperature, steam-to-carbon ratio or oxygen feed in the reactor) has been evaluated in a continuous chemical looping reactor, and methane conversions above 90% have been measured with (ultra-pure) hydrogen recovery from the membranes. For all the cases a maximum recovery factor of around 30% has been measured, which could be increased by operating the concept at higher pressures and with more membranes. The optimum conditions have been found at temperatures around 600 °C for a steam-to-carbon ratio of 3 and diluted air in the air reactor (5% O2). The complete demonstration has been carried out feeding up to 1 L/min of CH4 (corresponding to 0.6 kW of thermal input) while up to 1.15 L/min of H2 was recovered. Simultaneously, a phenomenological model has been developed and validated with the experimental results. In general, good agreement is observed, with overall deviations below 10% in terms of methane conversion, H2 recovery and separation factor. The model allows better understanding of the behavior of the MA-CLR concept and the optimization and design of scaled-up versions of the concept.