Macedon Moldovan

Universitatea Transilvania Brasov | unitbv · Department of Product Design, Mechatronics and Environment

Many study programmes on Engineering of Renewable Energy Systems appear worldwide as a consequence of the rising demand for specialists in this field, starting from research and development of materials, products and technologies to the renewable energy systems design, implementation, operation, maintenance and recycling. Such a study program has b...

A novel pseudo 3D design of solar thermal facades is presented in the paper based on triangle- and trapeze- solar thermal collectors developed in the Renewable Energy Systems and Recycling R&D Centre of the Transylvania University of Brasov, Romania aiming to improve their architectural acceptance and to provide affordable and clean energy, accordi...

Starting with January 2021, all new buildings and those undergoing major renovation must comply with the nearly Zero Energy Building standard imposed by the European Directive 31/2010. Besides specific indicators related to the energy performance and to the renewable energy share, the renewable energy systems must be implemented on or near the buil...

A solution to increase the electrical output of the photovoltaic systems relies on solar tracking mechanisms that increase the amount of received solar energy. The experimental results obtained during a monitoring period of one year are comparatively presented in the paper for five types of photovoltaic modules installed on a fixed platform (as ref...

Papers in this Special Issue should be related to the built environment and may discuss (but are not limited to) the following: Solar energy potential; Design of solar energy conversion systems; Estimation/forecasting of electrical/thermal energy; Electrical/thermal energy storage; Shading; Smart self-consumption of PV energy in local micro-grid; H...

Papers in this Special Issue should be related to the built environment and may discuss (but are not limited to) the following: Solar energy potential; Design of solar energy conversion systems; Estimation/forecasting of electrical/thermal energy; Electrical/thermal energy storage; Shading; Smart self-consumption of PV energy in local micro-grid; H...

The European Unions' ambition for the construction sector is to be carbon neutral by 2030 for new construction. Since 2021, all new buildings in the EU should have been constructed as nearly zero-energy buildings (nZEB). However, Eastern European countries struggle to implement the 2018 Energy Performance of Building Directive recast requirements....

Education plays a decisive role in achieving the 17 United Nations Sustainable Development Goals, by developing human resources and raising awareness at community level in promoting and implementing the concept of Sustainable Development and Sustainable Energy. In this context, Higher Education Institutions are responsible for both the training of...

Romania introduced in 2018 an amendment to the national law 220/2008 by including the Prosumer concept that allows investors in grid-connected photovoltaic systems with a capacity up to 27 kWp to receive a feed in tariff for the electricity delivered to the grid representing approximatively one third of the price paid when the electricity is consum...

New materials are obtained by transforming fly ash wastes into a valuable composite, with tandem adsorption and photodegradation properties. Mild hydrothermal synthesis, from titanium dioxide, platinum nanoparticles and zeolite materials obtained from a waste, fly ash, as support, was involved in the composite preparation. The platinum nanoparticle...

Novel triangle solar thermal collectors with colored absorbers were developed to improve the solar thermal facades architectural acceptance. Besides their nonconventional shape and colors, the collectors have an internal cavity instead of pipes to support the water flow. After indoor testing in standard conditions (water, 0.001kg/s, 1000W/m²) the c...

New materials are obtained by transforming fly ash wastes into a valuable composite, with tandem adsorption and photodegradation properties. Mild hydrothermal synthesis, from titanium dioxide, Platinum nanoparticles and zeolite materials obtained from a waste, fly ash, as support, was involved in the composite preparation. The Platinum nanoparticle...

To fulfil the requirements of the European Directive 31/2010, by January 2021, all new buildings and those undergoing major renovation must have renewable energy systems implemented on or near the building targeting the nearly Zero Energy Building standard. In areas with high density of buildings the available surfaces to install solar energy conve...

Solar thermal collectors are usually installed at a fixed tilt angle. In the design stage of the solar thermal systems, the optimal value of the tilt angle is numerically evaluated according to the latitude and the climate of the location, aiming to maximize the yearly received solar energy and thus the yearly thermal energy output. To experimental...

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, secu...

Space heating represents the largest share in the energy demand of the built environment, in temperate and cold climates. Therefore, the use of solar thermal systems to convert solar into thermal energy for space heating, along with domestic hot water production, represents a challenge in these climates where the number of sunshine hours is rather...

The chapter starts defining the built environment and its main features, following the international standards and codes. The trends in the development of the built environment are analysed, and the community concept is defined considering these trends and the specifics observed in the urban and rural areas. The energy demand in the built environme...

The chapter describes renewable energy sources, focusing on solar radiation and also addressing geothermal energy, bioenergy, wind energy and hydroenergy. Details on the solar radiation components, on monitoring procedures and equipment and on numerical modelling are discussed as tools for the assessment of the solar energy potential and the availa...

Sustainable communities are defined in direct relation with the nearly Zero Energy Community concept, where the energy is mainly produced using renewables and its consumption considers energy-saving measures implemented at residential, public and commercial building levels. The main steps in implementing renewable energy systems to meet the energy...

The chapter describes solar thermal systems implemented in the built environment to produce thermal energy for domestic hot water, heating and cooling. A design algorithm of the solar thermal systems is discussed, starting with the assessment of the thermal energy demand and of the solar energy potential used in sizing the main components. The opti...

The chapter describes photovoltaic thermal (PVT) systems, starting with their functionalities, types, advantages, disadvantages and the general functional scheme, outlining the electrical and thermal components and circuits. These systems represent good candidates when a higher solar fraction is targeted in covering the electrical and thermal energ...

The chapter describes the photovoltaic systems and the implementation solutions, along with the legal frame supporting their integration in the built environment in various regions all over the world, considering the access of the solar radiation to the PV modules along with the influence of meteorological parameters (e.g. humidity) on the PV outpu...

This book focuses on solar energy conversion systems that can be implemented in the built environment, at building or at community level. The quest for developing a sustainable built environment asks for specific solutions to provide clean energy based on renewable sources, and solar energy is considered one of the cleanest available energy on Eart...

One key component of the energy demand in the built environment is the thermal energy required for domestic hot water preparation. Currently, fossil fuels are mostly used to meet the thermal energy demand in the built environment, lately, solar thermal systems have been increasingly implemented, mainly for domestic hot water preparation, enhancing...

To be installed at any latitude from Northern and Southern Hemisphere, a solar tracking mechanism must perform the necessary angular strokes according to the latitude. For a dual-axis solar tracking system azimuthal type, the angular stroke limits depend on the latitude φ and Earth declination angle δ. In the paper, the analytical and graphical dep...

In the paper, a planar 2 DOF RSSR solar tracking linkage applicable for all latitudes is analyzed. The mechanism is contained in the vertical North-South plane of the observer. The coupler angle relative to horizontal plane defines the tilt angle χ of the active conversion surface and depends on the latitude and Earth’s declination. It can be modif...

One key component of the energy demand in the built environment is the thermal energy required for domestic hot water preparation. Currently, fossil fuels are mostly used to meet the thermal energy demand in the built environment; lately, solar thermal systems have been increasingly implemented, mainly for domestic hot water preparation, enhancing...

Buildings' facades usually have small sized and variously shaped opaque surfaces to integrate traditional (2 m ² , rectangular shaped)solar thermal collectors, thus resulting a reduced coverage factor (and thermal output)with rather low architectural acceptance. To tackle these issues, a novel type of flat plate, small sized (0.083 m ² )solar therm...

New solar thermal collectors with triangular and trapezoidal shapes and different colours (red, blue, green etc.) were developed in the Renewable Energy Systems and Recycling Research Centre, R&D Institute of the Transilvania University of Brasov, Romania to increase their architectural acceptance when integrated in buildings façades. An indoor tes...

The energy demand is increasing at global level and also does the related greenhouse gas emissions. Solutions to mitigate their effects on the climate are intensively investigated and among the studies, the implementation of Renewable Energy Systems (RES) at the building level to harvest the renewable energy sources as solar, wind and geothermal ar...

One of the greatest concerns nowadays is the growth of the world population. This is the main reason for the continuously increase of the electrical and thermal energy demand and consumption. It is a fact that the reserves of fossil fuels are limited and the exponentially pollution expansion imposes the development and the implementation of renewab...

Increasing the share of solar energy convertors installed on buildings asks for using all the suitably positioned places, including facades. However, facades integration asks for collectors with various colours and/or shapes to increase the architectural acceptance. Following these constraints, a new solar thermal flat plate collector was designed...

The sustainability challenges involve the built environment responsible for a large share in the total energy consumption. Steps toward a sustainable path were formulated and started to be implemented all over the world and, it is important to notice that the technical focus is mainly set on the energy production and consumption. Thus starting from...

In the near future, buildings will have to meet strict energy consumption standards in order to get as close as possible to the concept of nZEB (nearly Zero Energy Building), which means that buildings need to produce to a very large extent (10% for Romania) of their energy demand using renewable systems (RES) mounted on or near them. These standar...

In the paper a new concept of a pseudo-equatorial type 2DOF solar tracking mechanism is described. The mechanism is of parallel linkage type based on two kinematic constraints revolute-sphere (RS) which determine an 1 DOF planar loop RSSR with a passive rotation of the coupler. Two translational actuators directly linked to the frame are used to dr...

Geared linkage structure is defined in literature considering the type of linkage, usually four-bar or five-bar, and different versions are obtained by changing the input/output, the fixed link and the gears connections with linkage links. The paper proposes the structural synthesis of the planar geared linkage mechanisms with one pair of gears, as...

Developing efficient, sustainable, and affordable buildings requires combinations of passive and active measures that exploit specific onsite features. However, in temperate climates, reducing the heating demand (by south-oriented, triple-glazed curtain walls) has as a direct consequence an increased cooling demand. Using data collected over three...

The Solar Heating and Cooling Roadmap (2014) set a main focus “on increasing the share of solar thermal energy for the domestic hot water and space heating demand per building, from about 25% to about 60%” with installed systems on or near the buildings. The suitable implementation area at building level is limited, and optimally oriented facades h...

. Environmental challenges imposed by greenhouse gases are currently well recognized and a worldwide commitment tends to be reached, to replace fossil fuels (mainly responsible for global warming and climatic changes) with renewables. Concepts were formulated, as the Net Zero Energy Building (NZEB), although the current building stock mainly consis...

Increased energy demand and associated greenhouse gas emissions at the global level are directly related to population growth and economic development. To reduce the impact on climate change of the energy consumption in the built environment (responsible for up to 40% in developed countries) sustained efforts are being made to reduce demand through...

Five types of photovoltaic (PV) modules were comparatively analyzed considering the electrical output, efficiency and relative loss in efficiency, based on infield data collected in a temperate mountain climate, over 14 months. The mono-, poly-crystalline silicon, CdTe, CIS and CIGS modules were mounted on two identical platforms, installed close t...

International trade of goods largely uses maritime/transoceanic ships driven by engines using fossil fuels. This two centuries tradition is technologically mature but significantly adds to the CO2 emissions; therefore, recent trends focus on on-board implementation of systems converting the solar energy into power (photovoltaic systems) or heat (so...

Transportation is responsible at global level for one third of the total energy consumption. Solutions to reduce conventional fuel consumption are under research, to improve the systems' efficiency and to replace the current fossil fuels. There already are several applications, usually onsmall maritime vehicles, using photovoltaic systems to cover...

In the paper, performance assessment of the flat plate solar thermal collectors installed on the merchant vessels is analyzed. Performance evaluation of the collectors is made by taking into account solar radiance and two significant motions of the vessel: roll and pitch.The amplitude of the roll and pitch angles of a general cargo ship was identif...

For developing solar–thermal facades, new efficient flat plate solar thermal collectors are required, fulfilling the prerequisites of efficiency and architectural acceptance, with new shapes and/or new colours. A new flat plate solar–thermal collector, with isosceles trapeze shape was developed and stepwise optimised focussing on the insulation, th...

Nearly Zero Energy Building will be a mandatory status for all new buildings constructed after 31st December 2020 for European member states. This implies that, beside energy efficiency at the level of Low Energy Buildings, systems based on renewable energy sources must be implemented to provide energy savings and environmental benefits for space c...

The energy output of solar-thermal systems using flat plate collectors can be improved by tracking. Tracking is well known as a path for increasing the amount of solar radiation received by the collector; additionally the paper proposes a new concept that considers the inverse tracking as a viable option for protecting the collectors against overhe...

The concentrated solar energy convertors (e.g. solar-thermal dish, concentrated photovoltaic) require high tracking accuracy to maintain low incidence angles of the solar ray in relation with the concentrator optical axis (e.g. tracking accuracy of 0.05°…0.1°). This functional requirement is currently ensured by the high performance dual-axis solar...

A large variety of methods are mentioned in literature for the structural analysis and conception of parallel linkages, applicable to planar and/or spatial mechanisms developed for various applications as manipulators-robots, guiding mechanisms for car wheels and axle, solar tracking systems. Modern design requires today a unitary description of al...

The paper presents a detailed analysis on four-bar linkages, driven by linear actuators, used in solar tracking systems with large diurnal strokes. Based on the analysis of representative solutions in literature, a dimensional synthesis algorithm is proposed for a four-bar linkage, actuated by a linear actuator, linked with the connecting rod and w...

The transition towards Nearly Zero Energy Buildings (nZEB) requires the implementation of clean, efficient and affordable energy mixes in buildings. While the first two pre-requisites are related to a technical breakthrough that is expected for increasing the efficiency and sustainability of the renewable-based energy mixes implemented in the built...

This paper discusses relevant issue related to the architectural integration of active solar technologies (e.g. solar collectors) in the facades. In respect with the criteria which defines an optimal integration of solar technologies at the buildings level, the paper proposes a multifunctional solar facade concept that has the flexibility to be imp...

Photovoltaic (PV) systems implemented in the built environment must fulfill supplementary design restrictions related to the limited available space and to architectural integration, thus the need for increased output is a must and tracking, whenever possible, represents a feasible solution. Tracking significantly enhances the amount of solar radia...

Developing Nearly Zero Energy Buildings (NyZEB) represents a path toward sustainable communities and is required by international regulations, starting with 2018. Combined measures for reducing the energy demand and increasing the share of renewable energy systems in buildings are very much investigated for different types of buildings. One specifi...

Energy mix used in "Solar House" is currently composed of about 50% renewable energy sources (geothermal energy) and 50% conventional sources of energy (mainly electricity from national grid and less than 10% natural gas). The geothermal energy is extracted by the mean of a ground coupled heat pump which assures the heating load of the "Solar House...

A first aim of this paper is to present the comparative tracking efficiency analysis of bi-axial and mono-axial pseudo-equatorial tracking systems for the small photovoltaic (PV) platforms, implemented in Toronto, Canada (43°42′59″ lat. N). For comparative reasons some results were also simulated considering another location situated approximately...

Into the European Energy Performance of Buildings Directive context the "Solar House" is one of the first building in Braşov area intended to rich the status of net zero energy building. Once the building erected and Heating, Ventilation and Air Conditioning (HVAC) system completed a monitoring period was establish. A set of adjustments was perform...

Even if heat pump systems tend to be considered an efficient issue from the energy point of view, when considering the annual COP the building heat losses due to the envelope insulation is determinant for its capacity choice. As the flow rate of the groundwater influences the performance of the system, an analysis is presented to emphasise the impo...