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This case study shows the performance of a solar installation providing space heating and domestic hot water to a single-family house. Experimental thermal analogy was used to dimension the equipment, thus taking into account the building's high thermal inertia. © 1994. Peer Reviewed

8 pages, 10 figures, 2 tables Chemical-Looping Combustion (CLC) is a combustion technology with inherent CO2 separation and, therefore, without energy losses. CLC is based on the transfer of oxygen from the air to the fuel by means of an oxygen carrier (OC) in the form of a metal oxide. The OC circulates between two interconnected reactors, the fuel (FR) and the air reactor (AR). To scale up the CLC process for industrial application OCs materials suitable to work at high temperatures are needed. So far, Cu-based OCs had been proved to fulfil the requirements for an OC material, although operating temperatures lower than 1073 K are recommended. In this work, the behaviour of an impregnated Cu-based oxygen carrier (CuO-Al2O3) was studied in a continuous CLC unit of 500 Wth during long-term tests using methane as fuel gas and FR temperatures up to 1173 K and AR temperatures up to 1223 K. The behaviour of the oxygen carrier on the process performance was evaluated taking into account important aspects such as combustion efficiency, resistance to attrition, fluidization behaviour and preservation of the oxygen transport capacity and reactivity. It was found that both TFR and TAR had a great influence on the resistance to attrition of the particles. Stable operation for more than 60 h was only feasible at TFR =1073 K and TAR = 1173 K. However agglomeration or deactivation of the particles was never detected in any of the temperatures used. This is the first time that a CuO-Al2O3 OC, prepared by a commercial manufacturing method, and used at 1073K in the FR and 1173 K in the AR exhibits such a good properties: high reactivity together with high mechanical durability and absence of agglomeration. This result opens new possibilities for the application of Cu-based materials in industrial-scale CLC processes. This research was conducted with financial support from the Spanish Ministry of Science and Innovation (MICINN, Project CTQ2007-64400) and C.S.I.C. (200480E619). Peer reviewed

Higher education institutions play an important role in the transition processes to sustainable development through developing critical thinking (CT) in their students. The case of the Research Methodology course of the International Cooperation Master’s degree at the Universitat Politècnica de València is a paradigmatic case of experiential learning, where students face their own realities related to sustainable topics through an action research project with the Agroecological Market (AM). The learning methodology is project-based learning and helps the participants to deeply analyze problems related to the transition of socio-technical systems, such as sustainable food. The objective of this research was to analyze the contribution of project-based learning to students’ critical thinking through a qualitative analysis of the pedagogical outputs obtained during the course. The analysis and results are structured in three dimensions of critical thinking: (i) students’ critical attitude towards reality; (ii) students’ ability to reason and analyze in order to form their own rigorous judgments; and (iii) students’ capacity to construct and deconstruct their own experiences and meanings. The results show that project-based learning using a real-life scenario helped students reflect on their critical thinking and the challenges that our societies face for a transition to sustainability.

The electricity consumption of non-residential productive sectors represents a significant share of the overall energy consumption in the Member States of the European Union. Therefore, determining the main factors affecting the intensity of such consumption (defined as the ratio of the electricity consumed by the productive system of a given country to gross value added) is a research effort worth undertaking. The aim of this paper is to identify the main factors which affect such intensity with the help of a static panel data model, which is estimated with three different methods. Our results show that a higher degree of technological progress in the production systems and higher retail prices of electricity for non-residential consumers reduce such intensity. Other variables, which are statistically significant, lead to an increase of electricity intensity, including the accumulated stock of physical capital and the lagged gross fixed capital formation. The accumulated capital stock per unit of GDP is the variable with the highest influence on electricity intensity. Whereas the influence of price changes is limited, these results indicate that there is some rigidity to change energy intensity through demand-side policy measures, suggesting that they will need to be complemented with supply-side measures aimed at increasing low-carbon electricity generation capacity. Peer reviewed

In this paper we follow the tradition of applied general equilibrium modelling of the Walrasian static variety to study the empirical viability of a double dividend (green, welfare, and employment) in the Spanish economy. We consider a counterfactual scenario in which an ecotax is levied on the intermediate and final use of energy goods. Under a revenue neutral assumption, we evaluate the real income and employment impact of lowering payroll taxes. To appraise to what extent the model structure and behavioural assumptions may influence the results, we perform simulations under a range of alternative model and policy scenarios. We conclude that a double dividend –better environmental quality, as measured by reduced CO2 emissions, and improved levels of employment– may be an achievable goal of economic policy.

Passive performance of buildings is nowadays one of the key points, not only for reducing energy consumption of buildings, but also for decreasing >fuel poverty>. Among the constructive systems in buildings, façades are the ones having higher influence on thermal performance in urban spaces. Lime renders are specialized systems which can improve not only the durability of the support but also the thermal properties. According to previous researches, a modification of their radiative properties can reduce thermal fluxes between 24% and 89%. In this paper, the influences of the aggregate content in lime pastes, as well as the nature of the aggregates, colour and roughness, on the visible near and medium infrared reflectance are analyzed. Ten types of aerial lime mortars were prepared and two methods of reflectance determination were performed. Finally, the effect of the resulted reflectance on the constructive systems of façades was analyzed using pseudotime-dependent software, for which an annulation of the thermal fluxes or significant reduction of them can be observed, when modifying the aggregate nature. © 2014 Elsevier B.V. Peer Reviewed

Three pyrolysis biochars (B1: wood, B2: paper-sludge, B3: sewage-sludge) and one kiln-biochar (B4: grapevine wood) were characterized by determining different chemical and physical properties which were related to the germination rates and to the plant biomass production during a pot experiment of 79 days in which a Calcic Cambisol from SW Spain was amended with 10, 20 and 40 t ha(-1) of the four biochars. Biochar 1, B2 and B4 revealed comparable elemental composition, pH, water holding capacity and ash content. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by (13)C solid-state NMR spectroscopy. The FT-IR spectra confirmed the aromaticity of all the biochars as well as several specific differences in their composition. The FESEM-EDS distinguished compositional and structural differences of the studied biochars such as macropores on the surface of B1, collapsed structures in B2, high amount of mineral deposits (rich in Al, Si, Ca and Fe) and organic phases in B3 and vessel structures for B4. Biochar amendment improved germination rates and soil fertility (excepting for B4), and had no negative pH impact on the already alkaline soil. Application of B3, the richest in minerals and nitrogen, resulted in the highest soil fertility. In this case, increase of the dose went along with an enhancement of plant production. Considering costs due to production and transport of biochar, for all used chars with the exception of B3, the application of 10 t ha(-1) turned out as the most efficient for the crop and soil used in the present incubation experiment.