- ItemOpen AccessModelling the building-related photovoltaic power production potential in the light of the EU's Solar Rooftop Initiative(Elsevier, 2024) Molnar, Gergely; Cabeza, Luisa F.; Chatterjee, Souran; Ürge-Vorzatz, DianaDecarbonizing the building sector is key to meet the EU climate goals by 2050. Although the recent policies recognized the importance of on-site solar energy production in the energy transition, there are only a few modelling studies analyzing how much the gap between the technically possible and policy-driven power generation of rooftop photovoltaic (PV) panels can be reduced. This study, therefore, uses geospatial techniques and the high-resolution Building Integrated Solar Energy (BISE) supply model to estimate the main spatial and temporal characteristics of the rooftop PV energy production potential. To support decision-making, important implications of the Solar Rooftop Initiative action plan of the European Commission on the future dimension of the PV electricity supply are also assessed in the context of the achievable potential. The modelling results indicate that the current rooftop PV technical potential could be about 2.7 PWh, being in similar extent with the EU power consumption. The largest country-level PV potentials can be found in Germany, France, Italy and Poland, with an increase of 30% by 2060. Our findings also underline that by following the latest policies, major improvement could be achieved in the EU's rooftop solar energy production by around 2040, depending greatly on the structure and energy efficiency niveau of the future building stock.
- ItemOpen AccessMolten salts tanks thermal energy storage: aspects to consider during design(MDPI, 2024) Prieto, Cristina; Blindu, Adrian; Cabeza, Luisa F.; Valverde, Juan; García, GuillermoConcentrating solar power plants use sensible thermal energy storage, a mature technology based on molten salts, due to the high storage efficiency (up to 99%). Both parabolic trough collectors and the central receiver system for concentrating solar power technologies use molten salts tanks, either in direct storage systems or in indirect ones. But even though this is a mature technology, it still shows challenges in its implementation and operation. This paper underscores the critical importance of stringent design criteria for molten salt tanks in thermal storage technology. Focusing on the potential ramifications of design failures, the study explores various dimensions where an inadequate design can lead to severe consequences, even jeopardizing the viability of the entire technology. Key areas discussed include structural integrity, corrosion, thermal shock, thermal expansions, and others. By elucidating the multifaceted risks associated with design shortcomings, this paper aims to emphasize the necessity of thorough reviews and adherence to robust design principles for ensuring the success, safety, and sustainability of thermal storage technology.
- ItemOpen AccessSustainability of international research: evidence from an H2020 European project(Springer, 2023) Fabiani, Claudia; De Albuquerque Landi, Fabiana Frota; Cabeza, Luisa F.; Pisello, Anna LauraGreenhouse gas emissions reduction is a critical topic in the scientific community, as researchers strive to produce knowledge for the betterment of society. However, it is important to acknowledge that researchers themselves engage in activities that have a significant environmental impact. Group meetings and conferences are under the spot due to their extensive contribution to emissions through travel, catering, hosting, and other event-related activities. To address this issue, our work aims to conduct an environmental diagnosis of an ongoing H2020 European project, focusing on the impacts associated with the periodical group meetings organized in each country involved. We also sought to evaluate researchers' stance on online meetings and collected environmental and personal opinions through dedicated online forms. Results show that while travel is the primary contributor to emissions, catering, meeting structures, and hosting support should not be overlooked. Conference location and availability of public transportation also play a crucial role in the final impact of the event, as they affect directly the 87% share of emissions due to travels. Besides, using local distributors and reducing hotel stays (representing about 5% of the final impact) may reduce the potential environmental burden of these events. On the other side, besides the obtained positive feedback from online meetings, in-person activities are still more effective for reinforcing human bonds and collaborations.
- ItemEmbargoCharacterisation of the COMFORTBOARD gypsum board for thermal energy storage in buildings(Elsevier, 2024) Marín, Paula E.; Ushak, Svetlana; Gracia Cuesta, Alvaro de; Cabeza, Luisa F.Currently, the construction sector contributes considerably to the total energy consumption and greenhouse gas emissions into the atmosphere. Thermal energy storage (TES) systems are alternatives to increase the thermal inertia of buildings, aiming to use less energy, improve thermal comfort and reduce temperature fluctuations of interior spaces. One of the possible applications in buildings is to increase their thermal mass by impregnating phase change materials (PCM) in porous construction materials, e.g., gypsum boards. In this investigation, a commercial gypsum board impregnated with PCM (Knauf Comfortboard - BASF) was investigated by carrying out a structural and thermal characterisation. The thermal response obtained agrees with the product's technical data sheet provided by the supplier. The results of the thermal characterisation show that the inclusion of PCM in the gypsum board decreased the U-value by 2 % compared to the control sample (no PCM), increased the heat storage capacity by around 45 %, improved the thermal dynamic characteristics of the material by decreasing the thermal stability coefficient from 0.92 to 0.76 and increasing the thermal lag from 0.27 to 0.49 h. Our results sustain the potential application of commercial gypsum boards with PCM under environmental conditions across a wide range of daily temperature fluctuations (e.g., The North of Chile).
- ItemOpen AccessOptimizing the discharge process of a seasonal sorption storage system by means of design and control approach(Elsevier, 2023) Crespo, Alicia; Frazzica, Andrea; Fernàndez Camon, César; Gracia Cuesta, Alvaro deSorption thermal energy storage systems have higher energy densities and low long-term thermal losses compared to traditional energy storage technologies, which makes them very attractive for seasonal heat storage application. Although they have a lot of potential at material level, its operation and system implementation for residential application requires further study. The performance of a seasonal sorption thermal energy storage system strongly depends on the discharging process during the cold season. The present study analysed through numerical simulations different scenarios to enhance the thermal performance of a solar-driven seasonal water-based sorption storage, which supplied space heating and domestic hot water to a single-family house in a cold climate region. All studied scenarios were analysed under optimal control policy. The results indicated that the sorption storage could increase by 9 % its energy density if conservative and constant discharging temperature set points are considered, due to fewer interruptions during the discharge. The energy density of the sorption storage driven by solar energy was highly impacted by the weather conditions, and by the type and availability of low-temperature heat source. Indeed, the energy density of the sorption storage increased by 22 % using a water tank to assist the evaporator of the sorption storage, instead of a latent storage tank. The use of a dry-heater to assist the evaporator with environmental heat was not suitable for the climate studied due to the low hours of operation. The sorption storage system composed of 20 modules of LiCl-silica gel could obtain an energy density and a COP of 139 kWh/m3 and 0.39, respectively, if a constant low-temperature heat source (i.e, geothermal or waste energy) was available.