Solar Energy Conversion in Communities

Implementing the solar energy conversion systems has currently overpass the statement level. For a broad scale implementation, the pre-requisites has to be carefully formulated and fulfilled, according to the implementation site. The built environment represents a particularly challenging option, considering that besides functionality (and efficiency) the solar energy conversion systems have to fulfill various other conditions related to architectural acceptance and are facing, during operation, particular restrictions as e.g. shadowing. These aspects are discussed for the mostly used solar energy conversion systems implemented in the built environment (photovoltaic and solar-thermal systems) and emergent solutions are presented and analyzed.

The study presents a preliminary numerical investigation on the thermal behavior of a ground buried cylindrical solar thermal energy storage tank, operating in a solar district heating network. The proposed analytical model is based on energy balance and on the finite difference method. Due to the symmetry of the system, the model was considered one dimensional. A thermal solar field and an auxiliary gas boiler were considered as the thermal energy sources of the investigated system. The system serves a residential area situated in Zaragoza, Spain, with 1000 dwelling considered as heat consumer. The hourly variation of the operating conditions with different solar radiation and different ambient temperature were taken into account. The mathematical model was validated by comparison with results available in the literature and was further used in a case study, to prove the capability of this simple mathematical model to correctly describe the thermal behavior of a real solar district heating system with seasonal storage and to correctly adjust the storage tank volume with the solar field size and with the heating load. The solar fraction of the investigated system was determined in the range of (55.66–64.5%) depending on the size of the storage tank.

Since the first types of housing appeared in history, they were built in such matter that benefit from the Sun. Further in history, in Ancient Greece, the right to Sun was specified in the Civil Law, which gave each house the right to have direct sunlight. Today, in the context of environment protection for lowering the emissions of CO2, new ways are being searched for consuming less energy by living in a building and for producing renewable energy. We find the Sun once again as an infinite resource. By benefiting of its light, during the day we can obtain electricity and heat that we can use in our homes. The manufacturing industry for the active solutions offers a large variety of products that can be applied on building. The technological support being assured, the architects have the final task of finding new ways of integrating the solutions in the architecture of the building. Due its limitations of material and colours, the active solutions require special architectural approaches for obtaining a final coherent image of the building where the products blend in with the construction materials. While the active solutions are integrated in the building’s façade, the passive solutions have to be integrated in the volume of the building in a more unitary way. This paper analyses the newest active and passive solar systems and modern architectural solutions of integrating them in the building’s architecture.

The European Commission presented the European Green Deal in December 2019, aiming at making Europe the first climate-neutral continent by 2050. An Investment Plan was released in January 2020, mobilizing at least €1 trillion of sustainable investments over the next decade, to reach the ambitious climate and energy targets. The need for clean, secure and affordable energy supply is recognized as one of the main policy areas. Following this international context, one of the key research objectives in the Renewable Energy Systems and Recycling R&D Centre of the Transilvania University of Brasov focuses on the increase of the solar energy share in meeting the thermal energy demand of the buildings. Thus, novel solar thermal collectors were developed, with nonrectangular shapes (trapeze and triangle) and non-traditional colours (green, red, orange), to increase the architectural acceptance of the facade integrated solar thermal collectors. After indoor testing, four triangle solar thermal collectors have been installed on the southern facade of an outdoor testing rig for a long-term testing procedure. The collectors are parallelly interconnected and equipped with temperature sensors at each inlet and outlet and with digital flow meters that allow evaluating the thermal power output of each collector. The conversion efficiencies for each solar thermal collector are discussed in this paper for four representative clear sky days during the monitoring period. These efficiencies are compared with the values previously obtained on the indoor testing rig, outlining the behaviour of the novel solar thermal collectors in the outdoor working conditions.

In an oil market with prices per barrel less than half than few years ago, the use of classic fuels remains the economically viable and affordable solution. This aspect has a negative impact on the design, development and implementation of solutions based on the use of alternative energy sources in all sectors of activity. The present paper reviews the efforts made and the results obtained in order to provide energy to warships from sources other than the classical ones. Implementation of alternative sources of energy on warships is even more difficult, because on such a vessel there is generally no free space needed to place the systems. In this context, an analysis of the installation of solar thermal systems on military support vessels, which are not directly involved in combat and which are built like a merchant vessel, is presented. Also, three solar thermal systems are proposed for the preparation of DHW onboard vessels.

In this paper, an innovative mobile and sustainable robot for precision agriculture, named “Agri.q”, is presented. Characterized by a peculiar mechanical architecture and provided with specific sensors and tools, the Agri.q is able to operate in unstructured agricultural environments in order to fulfill several tasks as mapping, monitoring, and manipulating or collecting small soil and leaf samples. In addition, the rover is equipped with a top platform covered with solar panels, whose orientation can be exploited both to maximize the sunrays collection during the auto-charging phase and to permit a drone landing over a horizontal surface, regardless of the ground inclination. A particular attention to energy consumptions and sustainability has driven the mechanical design of the Agri.q powertrain: the weight reduction results into a limited number of small size locomotion motors, enhancing the importance of the harvested solar energy on the energy balance of the whole system. In this paper, all these characteristics are described and analyzed in detail. Moreover, some preliminary tests aimed at evaluating the energetic behaviour of the rover under different working and weather conditions are presented.

This paper presents a comparative study of the share of direct solar radiation received by flat solar converters (photovoltaic modules, solar thermal collectors) using four tracking systems of equatorial, azimuth, pseudo-equatorial, and pseudo-azimuth type. The study is developed for the Brașov, Romania location (45.65° N, 25.60° N), but its results can be extended for most mid-latitude regions. The effect of dual-axis vs. single-axis tracking is studied in the first part, highlighting high shares of received solar energy using single-axis diurnal tracking with an optimum fixed tilt angle. The four tracking systems with unequal steps tracking algorithms are compared with a fixed tilted system as reference. The paper outlines the ability of single-axis tracking in receiving high shares of direct solar radiation. This methodology allows the designers to rank the four tracking system types, for mid-latitudes, according to the criteria of solar energy receiving share and tracking angular strokes.

Degradation and reliability evaluation of solar photovoltaic (PV) modules is very critical to enhance the durability and lifespan of PV systems in operation. This study assesses the reliability and rate of degradation of a twelve-year-old ground-mount monocrystalline silicon (c-Si) solar PV modules exposed to the tropical climate of the sub-Saharan. The methods used for the assessment are visual inspection, current–voltage (I–V) curve characterization and thermal imaging. The process of partial shading was applied to determine the state of the bypass diodes. Results revealed a decrease in short circuit current (Isc) ranging from 7% to 16.4% whiles the reduction in open-circuit voltage (Voc) was between 11.4 and 17.1%. The decline in Fill Factor (FF) and maximum power were respectively between 11.3% to 24.2% and 34.5% to 41.4% with 3.19% per year decline in power output. It was found that Voc had the most significant impact on the decrease in the performance of the modules.

The paper analyses four of the mostly used photovoltaic (PV) simulation software tools (PVsyst, PV*SOL online, PV-Watts and PVGIS) from the produced electrical energy point of view. Based on the monthly and yearly estimated performances that are compared with the 6-years-long experimental values recorded from a PV system, recommendations are formulated on the accuracy and setup flexibility of each tool in order to replicate the infield PV application. The experimental data are recorded using a fixed tilted 2 kWp PV platform installed in Brasov, Romania (a mountain temperate climate location), containing two types of PV modules (m-Si and p-Si). The obtained results are useful for the prefeasibility studies of PV systems installed in similar conditions.

The research focus was to develop an off-grid hybrid RES mobile containerized system, combining the energy from the photovoltaic and micro-wind turbine source in order to directly providing the energy via DC-DC power supply. The applicability of the system was intended for irrigation and fertigation, in semi-dry and dry-sub-humid arid climates. The project tackled the most common technologies used in solar photovoltaic and small wind turbine applications combining them in an autonomous hybrid RES system that can be used in agriculture to power directly DC power supply (without the need of DC–AC conversion). During the development of the project an experimental model of the hybrid RES mobile system was deployed using a 2.16 kWp photovoltaic and 600 Wp wind turbine power source combined with a 5.3 kWh battery pack for extended use period. For the photovoltaic panels a mobile mechanical system of the photovoltaic source was developed and patented (no. A00730/12-11-2019) in order to increase the flexibility and maximize power production in real life conditions. Further testing in real file conditions is planned for a yearlong irrigation period in order to validate and further improve the energy management algorithm for the for irrigation and fertigation periods.

The characteristics of solar-generated electricity, including intermittency, uncertainty, and non-synchronous power generation, lead to some technical challenges to large-scale power grid integration. Each of those characteristics causes an economic challenge as well as reverse power flow, power quality issues, dynamic stability, and big data challenges. This paper aims to comprehensively investigate the existing challenges with the integration of high-penetration solar power plants, particularly Photovoltaic (PV) power plants, into power systems and corresponding solutions to improve the security, reliability, and resiliency of power systems.

Having in mind that European Union (EU) has committed to Paris agreement goal of keeping temperature at less than 1.5 ℃ above preindustrial level, has made decision to reach climate neutrality reached by 2050, and have greenhouse gas (GHG) emissions reduced by 50–55% by 2030, the issue of avoiding stranded costs should be immediately considered. Since natural gas boilers have life of 20+ years, and infrastructure even more, it is time to start preparing the exit strategy, in order to avoid stranded costs being loaded on consumers and market players.

Cyprus covers 93% of the energy demand using fossil fuels which are fully covered from imports. This does not only stand as a barrier to the various European Directives and measures which apply for all EU members, but it is also a drawback for the economy of Cyprus. Around 1000 tons of heavy fuel oil is required every year by the Electricity Authority of Cyprus to cover the energy demand. The household electricity prices including taxes paid in Cyprus are the 7th highest in Europe. From 2009, renewable energy systems have started to be used, but due to the price of the systems they were limited. However, price was not the main problem of the systems to explain why they didn’t expand more. Many other parameters are still affecting the use of RES in Cyprus; the public acceptance, the education of people, the environmental consciousness, but the most important is the motivation and ease of the applications and licensing from the government parties. Here in this study, an overview of the current energy situation is discussed and suggestions to increase the use of RES are mentioned as well. These include the use of electricity production RES for the domestic needs and measures for the improvement of energy efficiency of the building sector in general, which is the second biggest energy consumer in Cyprus after the commercial sector.

The blade is the most important element of a wind turbine, as it is the component that largely governs the productivity and it is the main source of efficiency optimization. A blade is defined by the airfoil type. This paper addresses three different airfoil types tested for different wind conditions. The versions considered are: the symmetrical NACA 0018 airfoil, the asymmetrical FX 63-137 airfoil—both of lift type and one drag type of scoop shape. Based on these versions, three sets of blades were obtained and used to form three vertical axis wind turbines which were tested in a wind tunnel. Except for the blade’s airfoil, all rotors had the same key parameters which refer to: rotor’s swept area, number of blades, height, diameter, aspect ratio, blade length, chord length, solidity and pitch angle. As expected for low wind speeds, the scoop bladed turbine showed significantly higher efficiency than the other two versions. It was also noticed that the performance is not influenced by the curvature position that can be oriented either radially inward or outward in relation to the rotor’s axis. For higher wind speeds the FX 63-137 turbine’s efficiency increased dramatically while NACA 0018 turbine displayed weak performance in all cases.

Many Vertical Axis Wind Turbines (VAWTs) have blades defined by asymmetrical (cambered) airfoils. There can be two possibilities regarding the orientation of their camber in relation to the rotor’s axis: radially inward or outward. The objective of this study was to experimentally determine the relevance of this aspect and the version that comes with higher efficiency. The asymmetrical FX 63-137 airfoil was considered. On the same turbine, the blades were first attached with the camber oriented inward and then oriented outward, for both cases the pitch angle being set to zero. The outward mode proved to be much more efficient. The optimization of the pitch angle was pursued for the camber inward version so besides 0° a few more values were tested: 8°, −8°, −16°. Even though the performance was significantly improved due to this step, the efficiency was still much lower than that for the camber outward mode for which the pitch angle was not optimized at all.

The use of energy mixes in communities giving value to the renewable energy sources available within or nearby the implementation location became one of the first research and innovation priorities. This trend particularly occurred in the context in which there is a local and regional (European) legislative support for the use of renewable energies, energy performance and energy efficiency that regulates the strategic objectives, the deadlines assumed and the methods of implementation thereof. This paper presents a general method of sizing a hybrid solar-biomass system for a community, starting from the location coordinates, the typical features of the built environment and the specific meteorological profile. The method integrates these data in the sizing process of the systems, based on the existence of district heating networks and available spaces for the individual or districtual installation(s) of hybrid solar-biomass systems and it selects the installation possibilities. In the end, the method is validated using a case study, the community in Taberei District of the Odorheiu Secuiesc City, using meteorological data to create the climatic profile using the Meteonorm software and operation simulations developed using the TRNSYS software.

Power generation sector worldwide accounts for high water withdrawal and consumption due to the hydropower generation and cooling of thermal power plants. Hence, the operation of the power generation sector is constrained by the availability of the water resources, as well as the addition of constrains on water resources used for other purposes, such as irrigation, flood control, water supply, agriculture, etc. The optimal utilization of water resources between the water and energy sector is defined under the term water-energy (or water-power) nexus. This study describes the implementation of hydrological LISFLOOD, Medium-Term Hydrothermal Coordination (MTHC) and Unit Commitment and Dispatch (Dispa-SET UCD) models for detailed analysis of impacts on the SEE regional power system for three different hydrological years. Results were validated based on the available ENTSO-E data for the average hydrological (2015) year. Results show increase in hydropower generation from 53.06 TWh for dry year, to 65.24 and 85.13 TWh for average and wet year, respectively, while the average electricity cost falls from 17.79 EUR/MWh for dry year, to 16.36 and 14.05 EUR/MWh for average and wet year, respectively. This analysis successfully replicates the methodology under the WATERFLEX project, with the novelty in run-of-river hydropower generation calculations in MTHC model.

According to the report provided by REN 21 (Renewable Energy Network for the 21st Century), over 73.8% of the amount of energy produced in Europe comes from non-renewable energy sources. However, the energy produced by fossil sources leads to an increase in the greenhouse gases emissions and to global warming. To reduce these effects, more and more countries have decided to increase the use of renewable energy sources. Sun, wind, water, biomass and geothermal energies are the main sources of renewable energy, but part of them are unpredictable and are not available all the time. Therefore, to meet the required energy, the hybrid systems, based on a combination of renewable energies, are preferred. These systems are often used in remote areas, but, due to the variability of the renewable sources, their design and analysis is difficult to be performed. An algorithm for the selection and design of a hybrid energy system based on solar, wind and/or hydro energy is presented in this paper depending on the renewable resources onsite available. The algorithm is applied to a case study that enables to select the appropriate hybrid system that provides the required energy for a guesthouse located in a remote area. Conclusions and recommendations are formulated on the design of hybrid systems.

Minimizing the energy inputs and decentralized energy production by using renewable sources are high priorities for the future of sustainable cities. Also, rehabilitation and reusing of decommissioned power plant sites are specific objectives of urban design when public decision is concerned. The paper presents an original solution aiming at the revival of five former industrial sites: Baia Mare, Braşov, Piteşti, Targu Jiu and Copşa Mică where tall industrial chimneys and available space is still existing. For each site, a solar park is proposed, where two different solar applications provide electricity: a solar chimney with upward air flow and a solar photovoltaic farm. After technical evaluations, the average installed power for each solar park is 5 MW. An economic assessment is provided based on energy production and other activities such as a charging system for electric vehicles and electrical buses used by the local transportation company and rental services to public/private consumers operating in the park. An analysis of the basic investment of approx. 19.5 M Euro—65% for the solar park and 35% for the architectural conversion works—revealed that the project is financially viable only if the revenue from the proposed activities is over 2.6–2.8 M Euro/year.

The Romanian coastline of the Black Sea has abundant seaweed resources, which create in summer period discomfort when the coastal area is flowed by thick lever seaweeds and that has a negative impact on the touristic area. That process reaches its maximum during the end of July and August. Usually, these seaweeds are collected when they reach the coast and are then stored in regional landfill waste deposits. Statistical data show that more than 9000 tons of seaweeds were collected during the last year. These were naturally degraded, causing an important environment impact. This paper focuses on the presentation of the results obtained at lab scale for the conversion of the Black Sea coast seaweeds. The first part of this work presents the state of art and the assessment of the chemical and physical composition of this feedstock. In the second part is presented the optimal technological scheme for developing one bioenergy model to produce biogas by the anaerobic digestion process of the pre-treated and untreated biomass. This digester aims to be used by the owners of the fish farms and the owners of the local costal touristic units that are affected by this algae blooming. The digester model also integrates one cogeneration unit designed to use the resulting biogas to produce bioenergy (electricity and heat) for the local use.

The work advances an original mechanism for the internal frontier (Lowest Unoccupied/LU and Highest Occupied/HO) molecular orbitals (MO), i.e., LUMO > HOMO versus HOMO(i) > HOMO(i + 1) versus LUMO(j) < LUMO(j + 1), for the electronic intra-conversion within molecular machine (MM) systems, here applied on a rotaxane with ring translational movements; the working structure of the present MM system [2]rotaxane 1H3+ is as follows: dibenzo[24]crown-8 ether macro-cycle, combined with the dumbbell type component containing a center of secondary ammonium (-NH2+-) and a 4,4′-bipyridine unit (bpy2+), while having the functional group of anthracene at one end, and a 3,5-di-tert-butylphenyl group at the other end, as stoppers. Accordingly, the MM system [2]rotaxane 1H3+ is considered to work under shuttle movement for which the special activation parameters of the ring shuttle processes for the basic induced process (A → B) and for the acid-induced one (AH ← BH) are identified. As a result, the quantum-orbitalic mechanism facilitates the Hydrogen activating gates (on/off MM) while driving the machine of the molecular complex within a fundamental acid–base process, i.e., within the “Hard and Soft Acids and Bases” (HSAB) paradigm; it leads to sustainable controlling and eventually to reusing and redirecting in mixed/integrated macromolecular systems the molecular activated energies involved in the individual MM (here I-to-IV) processes.

In this work ZnO/GO (Graphene Oxide) deposited materials in 3Qubit configurations with the arrangement of matrix-junctions are discussed, aiming to establish quantum transistor configurations for the quantum renewable energy mixes applications. The graphentronic integrated circuits are developed under applied voltage on the AND, OR, XOR input logical signals of the metal-oxide depositions, resulting in quantum transistors with 3-qubit outputs. Firs results of the output for the logical gates is performed; they can be further processed by using laws of Boolean Algebra and Virial theorem, following the electronic and also quantum tunneling activation resulted data of ZnO/GO depositions influenced by the diversity of metal oxide-graphene oxide placements. By activating quantum Hamiltonian gates it is possible to deliberate the quantum level repulsion effect taking place when valence-conduction graphenic band gap is stretched, including the synergic tunneling transport as a consequence of quantum interferences, resulting in increasing energy over earlier staking heterojunctions.

Aiming to obtain low-cost adsorbents for dyes and metallic ions from wastewaters, this study proposed cheap techniques such as carbonization of pine cones, coming from Romanian forests, using low temperature (500 ℃) in an auto-generated atmosphere and then, activation by using three types of chemicals: NaOH, KOH and H3PO4, respectively and low temperature for thermal treatment (700 ℃). The resulted adsorbents were characterized (by AFM, SEM, EDX, XRD, BET specific surface, porosity, FTIR and surface charge) and tested for removal of crystal violet dye (CV) and cadmium ions (Cd2+) from synthetic mono- or di-solute aqueous solutions. The effects of independent variables such as contact time, adsorbent dosage (0.1–0.2 g/L), initial dye concentration (2.5–20.0 mg/L) on the adsorption capacity of the proposed adsorbents were investigated and discussed correlated with the surface properties. The highest adsorption capacity was evidenced by the sorbent activated with NaOH (71.94 mg . g−1 CV adsorbed from single solute solution). In solutions with (Cd2+: CV)w ratio = 1:1, the presence of Cd2+ ions strongly diminished the CV adsorption with aprox. 28%. Cd2+ seems to be a redoubtable competitor for CV in the adsorption process. In case of adsorption from di-solute systems with (Cd2+: CV)w ratio = 540:5, the qmax for CV was 24.8 mg . g−1, while for Cd2+ cations, was 370.37 mg . g−1, for the same adsorbent, activated with NaOH. The adsorption processes follow the Langmuir model for all the tested species and the process kinetic is well described by the pseudo-second-order reaction model. Considerations on the sorption mechanism were made based on the experimental data.

Photocatalytic materials are intensively studied in environmental applications as self-cleaning coatings or for advanced oxidation processes for pollutants removal from wastewaters or from air. In the last decade, heterogeneous photocatalysis was largely reported as a viable path for removing pollutants from wastewater, targeting water re-use. For scaling up, the photocatalysts have to be efficient and affordable in usual working conditions, this is why VIS-active thin films gained particular attention. This paper presents the first results obtained in developing VIS-active composite thin-films, aqueously stable, based on graphene oxide dispersed in a TiO2 matrix. To get a stable film, a stepwise deposition process was employed, involving a first TiO2 layer developed by spray pyrolysis deposition over an FTO substrate, over which a composite TiO2–GO layer is deposited. A coherent temperature control over the deposition allows obtaining thin films with good crystallinity and photocatalytic response in the decomposition of methylene blue. The thin film was tested in a demonstrator photo-reactor and the factors influencing the process efficiency are detailed discuss.

Self-cleaning thin films are applied as top coatings (usually deposited during the manufacturing stage) on the solar glass of photovoltaic (PV) modules. This prevents dust and grime accumulation on the glazing and maintains a good solar radiation transmittance to the PV cells. Due to weathering, the self-cleaning coating can be partially destroyed over time and in-situ re-application on the already installed PV modules may be a viable option. The requirements for the self-cleaning coating are: low-cost materials, easy deposition at ambient temperature, high transparency in the UV–VIS range, high photocatalytic efficiency to degrade organic pollutants using the solar radiation and low contact angle to wash off possible by-products of the photocatalytic process and/or various other pollutants stacked on the surface. These requirements were reached at laboratory level on 1.5 × 1.5 cm2 solar glass substrates, using a TiO2–WO3–rGO composite thin film obtained using a stable dispersion of sol–gel powder. When scaling up to 20 × 30 cm2 surface, thin film homogeneity becomes difficult to maintain. The deposition conditions (spraying area, duration) were re-optimized to support the uniformity of the chemical, morphological, optical, photocatalytic and wetting properties.

Novel photocatalytic materials are currently required for advanced wastewater treatment or for self-cleaning applications. For these applications, (super)hydrophilic surfaces must be developed and UV photo-induced hydrophilicity can be a viable path to obtain such materials. This paper reports on the hydrophilicity variation of the novel TiO2/TiO2 GO composite thin films obtained by spray pyrolysis deposition (SPD) followed by the deposition of a diluted sol by spraying at 100℃. The thin films were kept in dark (in normal atmospheric conditions) and under UV irradiation, at different exposure periods (up to 72 h) and the variation in the contact angle of water were analysed along with the morphology, surface composition and roughness (RMS) to correlate the hydrophilicity with the materials properties. The results show an increase in the contact angle values over time for the samples kept in dark and a decrease of it when the films were UV irradiated mainly as results of the roughness variation, due to slight changes in the thin film (surface) composition. The thin films were further tested in methylene blue decomposition and the effect of the hydrophilicity on the photocatalytic efficiency was investigated. The results show that, in the experimental conditions, a pre-conditioning treatment of the thin films can lead to more efficient processes.

This study aims to better correlate the properties of nanocrystalline graphite/graphene thin films with the individual deposition parameters, such as RF power, substrate temperature, chamber pressure and other influential factors. The carbonic films were grown using methane as gas precursor by capacitively coupled radiofrequency plasma enhanced chemical vapor deposition. The morphology, structure and electrical properties of the thin films deposited on both Si and SiO2 substrates at different process parameters were investigated through scanning electron microscopy, Raman spectroscopy, atomic force microscopy and four-point probing.

The integral transform technique, merging the Anisimov-Nolte Two Temperature Model with the Cattaneo—Vernotte equation, is used in the present paper. Using the integral transform technique, relatively simple expressions for the electrons and phonon temperatures can be obtained, which can provide great help for the experimentalists especially for laser flash experiment on graphene. The obtained expressions are easy to handle in the software package MATHEMATICA 9.0.

Composite materials have many obvious advantages, as they can be made to be lightweight, strong, corrosion and heat resistant, flexible, transparent and more according to specific needs. Composites are already used in many industries, like aerospace, automotive components, wind turbine blades, building materials, medical utilities and others. Composite materials’ merits and potential assures ample research in the field which is hoped to bring future developments and implementations in additional markets. The presence of graphene can enhance the conductivity and strength of bulk materials and help create composites with superior qualities. Graphene can also be added to metals, polymers and ceramics to create composites that are conductive and resistant to heat and pressure. From GO and a boron-phosphate glass a mix raw material with several % GO was made. The mix was pressed and thermally treated in order to obtain a GO—glass composite. Lithium-zinc-boron-lead-phosphate glass with 3% GO was melted-quenched at 700 ℃ melting temperature and (Tg + 10 ℃) annealing temperature, for 2 h. GO-glass composites were characterized by atomic force microscopy (AFM), Raman and FTIR Spectroscopy.

Responding to the increasing concern for preserving a clean environment, the development of self-cleaning coatings attracts growing interest, since they already demonstrated efficiency in pollutants removal. Considering the fundamental materials’ properties, the target is to develop materials demonstrating enhanced photoactivity under visible light irradiation, corroborated with controlled hydrophilic character. Two major conditions attract the research interest to provide promising, viable solutions: the material should be earth-abundant, non-toxic for humans and environment and the deposition technology should be affordable in terms of costs and energy, and does not lead to environmental risks. This paper presents the development of two types of materials: ZnO, obtained by spray pyrolysis and the ZnO–GO composite, deposited by combined sol–gel and spraying technique. The as-prepared samples proved promising self-cleaning properties. Both hydrophilicity and photodegradation efficiencies were enhanced by a surface pre-activation, consisting of samples’ exposure in dark and UV irradiation.

This keynote presentation examines the current status of renewables in the world. The presentation starts with some facts about the climate change, global warming and the effects of human activities such as the burning of fossil fuels on the climate problem. It then examines shortly the current status of conventional resources of energy, followed by a general outline of the status of renewables in the world, which includes the shares with respect to conventional fuel use for electricity and power and jobs created. Then the basic forms of renewables are examined in some detail, which include solar thermal, both for low and high temperature applications, photovoltaics, hydro power, onshore and offshore wind energy systems and biomass/biofuels. In all these the basic technology is presented followed by the current status as well as the prospects of the technology and new research findings.

The European Union is committed to becoming the first climate neutral continent by 2050. Transitioning to clean energy is key to combating climate change and it plays a central role in the new European Green Deal.

Research on waste recycling and developing environmentally friendly materials having good performances and low costs as alternatives to those currently used, in particular in construction and architecture, attempts to minimize the unsustainable use or harmful materials, which also incorporates large amounts of energy. A number of studies demonstrate the use of cardboard waste with sufficient compressive strength offering an alternative for traditional building materials (concrete and steel). In this work the most feasible methods for eco-design and construction of a residential house were analyzed, using corrugated cardboard waste as building material, in the form of old corrugated cardboard panels made without adhesives, by including them between the elements of the supporting structure, made of wood. The analysis shows that the resulted environmental performances recommend the use of recycled corrugated cardboard waste as a construction material with good performance in thermal insulation.

The paper aims to explain details related on the innovative potential of mechatronics as environment for smart education, organizational learning and sustainable development, to enhance the pillars of a Smart and Sustainable Society. At the EU level these pillars are defined as smart governance, smart economy, smart mobility, smart environment and sustainable development, smart living and smart people. Mechatronic platforms as complex technical systems integrating elements of mechanical engineering, electrical-electronic engineering and computer science engineering are the basic infrastructure of these environments. The National Mechatronic Platform (NMP) is conceived as a national mechanism of a network structure to activate the human and material resources at all the levels and to ensure the systemic approach of the complex problems regarding smart education, organizational learning and sustainable development in Romania. Based on this technical and scientific support, the Platform for Smart Education, Organizational Learning and Sustainable Development will be developed. Specific details are also presented in the paper. The proposed solutions are useful to get the main goals of the UN 2030 Project too. As it is known, Mechatronics (the backbone), Cyber Physical Systems (CPS) and Internet of Things (IoT), are the triangle of the twenty-first century technologies, the foundation of the 4.0 industry

Using renewable resources nowadays is not only a reality but also a necessity. However, when designing architectural spaces we are still rather considering a sole main function or related functions, thus making the building easier to manage. In this paper we wish to present a vision for adapting representative buildings in a community in order to respond to sustainability issues (from social sustainability to economic and environmental sustainability), highlighting ways of producing and better using solar energy. In this context the building itself can also become a promoter by informing about (while also making use of) renewable energy systems and principles. From sports grounds to museums, we shall see how different functions can be accommodated and integrated in a single area, leading to using resources locally produced in real time and in that space instead of producing, storing, sharing energy on longer distances. In this scenario the consumer is drawn towards the place of production and consumption, having his needs met while also having something to gain at various levels—from chances for personal development to chances of social interaction.

“The Sun does not realize how wonderful it is until after a room is made.”—Louis Kahn. The sun is also a building material; not by itself but in the architectural concept, the sun—light gives value to the space. Encapsulated in some building products, the light and energy of the sun are used to provide active or/and passive gain; sun control is a field of architectural approaches and there are products that provide protection against sun glare and heat. Professional education develops the knowledge to use the sun or protect against it, from the concept to the detail. At least in theory. In practice, a poor or incomplete design generates a chain-reaction: problems that are difficult to repair and that generate other problems that can be sometimes solved only with huge costs. As in the case of all building products, if the specifications are not respected, the product will fail in practice. In any activity in life, the better the “story”/the “script” is analyzed, planned and carried out considering as many angles as possible and integrating specialists from other connected fields, the less bad surprises may occur. A building will never be perfect. It is an art to identify the smallest compromise (however, the compromise is always there). Teaching on how to do things right is fine but the dimension of what is the meaning of “to do right”, can also be understood while tackling failed systems. A failure, analyzed and understood, brings light not only into the specific system but also in the broader field of knowledge and emphasizes and strengthens the theory. The paper presents several examples, including cases of failures, in relation with the sun and light and draws conclusions about the importance of tackling the design of the building considering the biunivocal relation between the architectural object and the natural and anthropic environment.

All debates on the Romanian educational system should consider the need to create a sustainable built environment. However, as long as educating our younger generations is one of society’s core purposes, building new schools remains one of our essential challenges. Over 80% of the existing Romanian school buildings were built before 1970. Box type buildings, designed to restrain learning experiences to indoor environments hardly meet the needs of today’s generations, already compromising the needs of future ones. Almost every rehabilitation or extension project of a school building aims minimal safety or comfort, while restricting to a minimal budget. Schools’ users are completely absent from any dialogue with the design teams and educational architecture practice in Romania is not grounded on research. Research is a dynamic phenomenon, providing complex and sometimes contradictory data, which encourages the continuous testing of new ideas. Beside healthcare, education is the most important architectural program that should be approached through Evidence-based Design (EBD). This paper emphasizes the necessity of adapting our building legislation based on systematic Post-Occupancy Evaluations (POE). The primary objective is creating evidence: what works, what should be avoided, what and how could be improved in planning and designing sustainable educational facilities. One of the main results consists in proposing a framework for implementing the POE method in Romanian schools. School should not be a capsule where education takes place. Our public school buildings should transform into community landmarks, which can provide significant learning experiences and promote sustainable ways of understanding education.