ElsevierFerrer Gisbert, CM.; Ferran Gozalvez, JJ.; Redón Santafé, M.; Ferrer-Gisbert, P.; Sánchez-Romero, F.; Torregrosa Soler, JB. (2013) AbstractThis paper describes a new photovoltaic floating cover system for water reservoirs developed jointly by the company CELEMIN ENERGY and the Universidad Politécnica de Valencia. The system consists of polyethylene floating modules which, with the use of tension producing elements and elastic fasteners, are able to adapt to varying reservoir water levels.A full-scale plant located near Alicante (Spain) was built in an agriculture reservoir to study the behaviour of the system. The top of the reservoir has a surface area of 4700 m 2 but only 7% of such area has been covered with the fixed solar system.The system also minimizes evaporation losses from water reservoirs.

Universities play an important role among public institutions because they initiate huge purchasing and contracting activities and contribute to sustainable development through education, research, and day-to-day operations. Existing studies on green public procurement (GPP) practices at Spanish universities focus on products and services. For this study, a total of 316 procedures were collected and analysed from the calls for tenders made by Spanish public universities between 2016 and 2017. The environmental criteria involved in the tenders and their weights were classified by subsector, geographical scope, and project budget. The results of this study show the use of environmental criteria in the works tendered by Spanish public universities is low (19.2%) in comparison with the results of other studies. It is therefore necessary to encourage GPP practices in the contracting process to comply with the environmental policies that universities have defined as part of their institutional policies.

ElsevierAparicio Fernandez, CS.; Vivancos, J.; Ferrer Gisbert, P.; Royo Pastor, R. (2014) AbstractA model for a building with ventilated façade was created using the software tool TRNSYS, version 17, and air flow parameters were simulated using TRNFlow. The results obtained with the model are compared and validated with experimental data. The temperature distribution along the air cavity was analyzed and a chimney effect was observed, which produced the highest temperature gradient on the first floor. The heat flux of the external wall was analyzed, and greater temperatures were observed on the external layer and inside the cavity. The model allows to calculate the energy demand of the building façade proposing and evaluating passive strategies.The corresponding office building for computer laboratories located in Valencia (Spain), was monitored for a year. The thermal behaviour of the floating external sheet was analyzed using an electronic panel designed for the reading and storage of data. A feasibility study of the recovery of hot air inside the façade into the building was performed. The results obtained showed a lower heating demand when hot air is introduced inside the building, increasing the efficiency of heat recovery equipment.

Research on current practices and the state of green public procurement enables the identification of areas that can be improved, as well as opportunities to improve the tendering procedures from an environmental point of view. To understand the behaviour of local, provincial, and regional administrations concerning green public procurement, a case study on the Valencia region of Spain is made. The Valencian region is one of the most important communities in terms of population, number of contracting authorities, and weight in the Spanish Gross Domestic Product. In this study, a total of 967 procedures were analysed from calls for tenders made by municipal, provincial, and regional administrations in2016 and 2017.The results of this study show that the use of environmental criteria is 19.7% and the average weight is 4.1 out of 100. The civil engineering subsector, more than the building subsector, employs environmental criteria, particularly in projects tendered by regional administrations, whereas for projects with large budgets the level of use is similar for both subsectors. It is necessary to encourage plans to improve Green Public Procurement (GPP) practices in the Valencian administrations, especially those with a local scope such as municipalities.

a b s t r a c tHydroelectric power is obtained by harnessing the potential energy of a mass of water flowing along a river bed to convert it first into mechanical and then into electrical energy. The system is therefore both clean and autonomous and has a high potential for development.A small hydropower plant has an installed power capacity of below 10 MW and is considered run-ofriver when it diverts part of a river flow to generate its electricity.The use of multicriteria techniques in environmental decision making, including selecting between various alternatives, is important when it involves complex decisions in a number of disciplinary fields. The most widely used of these techniques is the analytic hierarchy process (AHP).This work proposes an application of the AHP method to select the best alternative for the installation of a small run-of-river hydropower plant. The systemization of the process, together with its mathematical rigor, means the best project will be selected from the available technical, economic and environmental alternatives.The main criteria identified in this study for the selection of RoR plant are: protected fauna, fish population, water quality, landscape quality, flow regime and vegetation. Finally, the best alternative was the project of the company Energia of Galicia.

Construction is one of the most important sectors in terms of economic volume and number of employees. It represents approximately 10% of the Gross Domestic Product of the European Union and employs 7% of its total labour force. In a construction project, procurement is employed in many of the stages, so it can constitute an adequate mechanism to integrate sustainability initiatives. Research concerning economic aspects in procurement has always been present in the construction sector, whereas research related to environmental aspects has been gaining attention in the last years. Nevertheless, social aspects are still not very present in the literature on public procurement. The main objective of this research is to analyse the use of social criteria in public tendering processes of public works in the Valencian region of Spain. The results show that Valencian public entities include social criteria for the 11.7% of adjudicated public works. This value is very low when compared with other studies developed in different countries worldwide. Social criteria, just like in other cases, are used more frequently the larger the budget of the project and the longer the execution time. The average weight of social criteria for the tendering process is low (7.0 out of 100), although entities that usually consider these criteria are aware of their importance and give them a higher weight, in global terms.

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The design of near zero energy offices is a priority, which involves looking to achieve designs which minimise energy consumption and balance energy requirements with an increase in the installation and consumption of renewable energy. In light of this, some authors have used computer software to achieve simulations of the energy behaviour of buildings. Other studies based on regulatory systems which classify and label energy use also generally make their assessments through the use of software. In Spain, there is an authorised procedure for certifying the energy performance of buildings, and software (LIDER-CALENER unified tool) which is used to demonstrate compliance of the performance of buildings both from the point of view of energy demand and energy consumption. The aim of this study is to analyse the energy behaviour of an office building and the variability of the same using the software in terms of the following variables: climate zone, building orientation and certain surrounding wall types and encasements typical of this type of construction.