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SZENT ISTVÁN UNIVERSITY GÖDÖLLŐ
Department of Physics and Process Control
20th WORKSHOP ON
ENERGY AND ENVIRONMENT
BOOK OF ABSTRACTS
ISBN 978-963-269-450-4
December 4-5, 2014
Gödöllő, Hungary
2
3
PREFACE
Successful events in the series of the Seminar/Workshop on Energy and Environment (EE)
were organized yearly since 1995 under the auspices of the Department of Physics and
Process Control, Institute for Environmental Engineering Systems, Szent István University
Gödöllő, Hungary including active participation also from foreign institutions working in the
field of the application possibilities of renewable energy resources.
The aim of the Workshop is provide a forum for the presentation of new results in research,
development and applications in connection with the issues of energy and environment. In one
part of the Meeting the participants had presentations on the different aspects of energy and
environment, the abstracts of which are included in this booklet.
During the Workshop it was possible for the participants to visit the new developments of
solar installation at the Department of Physics and Process Control as meteorological station,
PV units, solar water collectors, PV/T hybrid collector, transparent insulation wall, solar
operated greenhouse, solar dryer, solar data logging/monitoring system, solar heated
swimming pool, mobile PV kit, and the 10 kWp grid connected photovoltaic system.
Beside the presentations a discussion was held on the future steps and further project
possibilities concerning energy and environment issues. The outcome of this session was that
the participants confirmed their willingness to set up projects which is beneficial for the co-
operating partners and also serves the development of the dissemination of appropriate
technologies to fulfil the requirement of energy and environment.
The organisers are highly appreciated for support of projects OTKA K 84150 and PV
Enlargement. Thanks also for the support of the Hungarian Solar Energy Society and the
Mechanical Engineering Doctoral School, Szent István University, Gödöllő, Hungary.
Prof. I. Farkas
Founding Chairman of the Workshop
Department of Physics and Process Control
Institute for Environmental Engineering Systems
Szent István University
Gödöllő, Páter K. u. 1. H-2103 Hungary
E-mail: Farkas.Istvan@gek.szie.hu Tel: +36 28 522055 Fax: +36 28 410804
http://fft.szie.hu/ee2014.html
4
20th
WORKSHOP ON ENERGY AND ENVIRONMENT
December 4-5, 2014, Gödöllő, Hungary
Program
December 4 (Thursday)
14.30-17.00 Registration
Visiting the Department of Physics and Process Control
Visiting the exhibition of the solar installations of the Department
December 5 (Friday)
09.00-09.15 Opening the Workshop by:
Prof. I. Farkas Director of Institute
Institute for Environmental Engineering Systems
Szent István University, Gödöllő, Hungary
Prof. I. Szabó Dean of Faculty
Faculty of Mechanical Engineering
Szent István University, Gödöllő, Hungary
Session 1 Chairman: Dr. J. Mellmann
09.15-09.30 I. Farkas: Towards to the third generation photovoltaic technologies
09.30-09.45 H. Scaar, F. H. Scaar, F. Weigler, J. Mellmann, K. Gottschalk, Á. Bálint, Cs. Mészáros, N. Nagy, R. Kosztolányi, I. Farkas: Numeric simulation of heat and mass transport in soil samples
09.45-10.00 Cs. Mészáros, Á. Bálint: Solitary wave type solutions of the convection-
diffusion processes through porous media and relevance of the coupled
diffusion processes
10.00-10.15 P. Vladár, P. Víg: Influence of the mass flow control on the performance of
solar collectors
10.15-10.30 S. Bartha, V. Ursu, L. Borotea: Environmental influence and impact of the new
developed solar parks
10.30-10.45 A. Szilágyi, I. Seres: Analysis the performance of absorption cooling system by solar energy
10.45-11.15 COFFEE BREAK
5
Session 2 Chairman: Prof. P. Weihs
11.15-11.30 P. Weihs, S. Hasel, E. Mursch-Radlgruber, C. Gützer, H. Trimmel, S. Krispel, M. Peyerl: Investigation of the effect of sealed surfaces on local climate
11.30-11.45 G. Vizi: Unused energy in our homes in the form of electromagnetic wave
11.45-12.00 I. Seres, F. Kiss, B. Sipos-Szabó: Spectral measurement in connection with
photovoltaic energy production
12.00-12.10 M. Gaucher: Solar air conditioning
12.10-12.20 T. Carrasquinho: Analysis of solar radiation components
12.20-12.30 B. Cemre Yesillik, I. Farkas: Integrated use of solar energy
12.30-12.40 F.P. Cazarim: Autonomous solar photovoltaic system
12.40-14.00 LUNCH BREAK
Session 3 Chairman: Dr. S. Bartha
14.00-14.10 G.L. Farias: Roof integrated solar collectors
14.10-14.20 T. Maltempi: Hybrid solar systems
14.20-14.30 E. Tsuchida: Concentrated solar collectors
14.30-14.40 F. Leonardo: General considerations on solar vacuum tube collectors
14.40-14.50 M. Okado: Solar heated greenhouses
14.50-15.00 S.E. Matsumoto: Passive solar applications
15.00-15-30 COFEE BREAK
15.30-15.40 V. de Carvalho Silva: Renevable energy scenario
15.40-15.50 D. Silveira Costa: Solar energy scenarios
15.50-16.00 F.W. Foletto: Enegy intensity between counties
16.00-16.10 L. Lamb, I. Farkas: Solar heating of open- air swimming pools
16.10-16.20 M. Marzec: Grid-connected photovoltaic systems
16.20-16.30 D. Suleimenov: Hybrid renewable energy systems
16.30-16.40 D. Rusirawan, N.I. Muhlis, I. Farkas: Characterization of two type photovoltaic
modules using Matlab Simulink
16.40-16.50 J. Tóth, J. Buzás: Reneval of a data loging, monitoring and control software in LabView in connection with a database server development
16.50-17.00 CLOSING
6
TOWARDS TO THE THIRD GENERATION PHOTOVOLTAIC TECHNOLOGIES
I. Farkas
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055, Fax: + 36 28 410804, Email: Farkas.Istvan@gek.szie.hu
This paper deals with the new priorities and application possibilities of the photovoltaic (PV)
technology. The photovoltaic technologies will show their significance for longer period. The
most important standpoints characterising the PV industry are to be discussed. The new
features of the PV technology and the applications are also studied in a great extent. It
includes new type of modules, especially the third generation ones, along with their colouring,
extra size and the fixation system. Examples are shown for such application possibilities.
Within the use of solar energy the solar thermal field identified at a lower innovation potential
however their application shows large varieties. Especially the production of electricity from
solar thermal is a preferred solution.
In spite of the recent economic situation all over the world a significant yearly increase of
photovoltaic module production and their installation were performed in last couple of year
period. However, it can be observed a sensitivity of the market change on the photovoltaic
industry, the PV technologies still show increasingly high priority.
At the same time, there are some very important features which are characterising and
influencing the PV manufacturing and applications industry as for example the new type of
fixation and the colouring the cells. It can also be observed a very strong competition between
the crystalline and the thin film technologies and also the third generation of PV technologies
developing rapidly. Among that it is enough to mention the organic PV. The environmental
impact of the use of PV systems is increasing, as well.
In return the roof is covered with a special plastic cover which causes some difficulty in the
fixation of the support for the modules. For such a purposes, for example, it can be used the
solution of Tectum flat roof system, which has a feature of quick installation, lightweight (~12
kg/m2) and high yields.
The attractiveness of the applications is increased with the use of the different colours of
modules. The possible colours of the planned semi-shade cells show high variability. The
main features of such modules are the standard framed unit with a tempered front glass and
the durable clear polymer substrate. The module has got 50% transparency, so it can be used
to increase natural light behind the module along with providing energy production and surely
some shading.
Concerning to the photovoltaic applications the roof integrated and the ground positioned
autonomous and grid-connected solutions are the most typical solutions. The solar
photovoltaic potential can be calculated on the basis of the available area all through a
country. Beside the energy saving opportunities the environmental impact of the use of
photovoltaic technology can also be significant effect. For the estimation of the total reduction
of the CO2 emission the relative value of 0,82 kg/kWh is to be applied.
Acknowledgement: This work was carried out within the project OTKA K 84150.
7
NUMERIC SIMULATION OF HEAT AND MASS TRANSPORT IN SOIL SAMPLES
H. Scaar1, F. Weigler
1, J. Mellmann
1, K. Gottschalk
1
Á. Bálint2, Cs. Mészáros2, N. Nagy
2, R. Kosztolányi2, I. Farkas
2
1Leibniz-Institut für Agrartechnik Potsdam-Bornim e.V. (ATB)
Department of Post Harvest Technology, Max-Eyth-Allee 100, 14469 Potsdam, Germany
Tel.: +49 331 5699 314, Fax: + 49 331 5699 849 Email: kgottschalk@atb-potsdam.de 2Dept. of Physics and Process Control, Szent István University, Gödöllő, H-2103, Hungary
Heat and mass transport in soil columns is investigated by using modelling techniques as
DEM (Discrete Element Method) and CFD (Computational Fluid Dynamics). Coupling of
both methods is one of the objectives. In a parallel project measurements of temperature and
moisture content distributions in soil samples are performed. Experimental and modelling
results are compared for validation. The objectives are to find the influences of soil structure
on convection and diffusion, and the influences of drying processes on changes of soil
structure.
Simulations of the dynamics of particle-based systems with basic geometry of spherical (2D
or 3D) particles are made with DEM (Fig. (a)). Solid and granular materials are composed of
basic geometry (bond, adhesive forces). Material properties and structures (arrangement of
particles with random size distribution) must be determined firstly (Fig. (b)). Simulation of the
movement and interaction of discrete structures is made. Automatic detection of contacts
throughout the calculation cycle can be done. For fully dynamic simulation the Newton's law
(F = m ∙ a) is solved with explicit finite difference method (FDM). The time step is automatically adapted to the local conditions.
Consecutive transient CFD simulation result in temperature (Fig. (c)) and moisture content
distributions in the soil. It can be demonstrated that coupling DEM (structure model) with
CFD (air flow model) is possible, but needs highly extended implementation to produce
sequences automatically. Air flow pattern in porous structure (soil) and change of structure
due to drying (shrinking / shifting / clumping) with consequences to formation of macropores
can be modeled.
The extension with reaction kinetics, microbial mass transfer, gas development in soil,
dependent on T, rH, c. (gas components), is the objective for further investigations.
(a) (b) (c)
Fig.: (a): Bulk material (DEM) - (b): Porosity (DEM) – (c) Temperature (CFD)
Acknowledgement: The project is funded (in 2014-2015) by DAAD 57061276 and MÖB 21 430 008.
8
SOLITARY WAVE TYPE SOLUTIONS OF THE CONVECTION-DIFFUSION
PROCESSES THROUGH POROUS MEDIA AND RELEVANCE OF THE COUPLED
DIFFUSION PROCESSES
Cs. Mészáros1, Á. Bálint2
1Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary 2Óbuda University, Institute of Environmental Engineering
Budapest, H-1034, Hungary
In this paper an attempt is given for reviewing of some of the most actively investigated
propagation processes taking place in dissipative macroscopic continua. It is assumed, that the
contemporary extended irreversible thermodynamics is the most natural frame for theoretical
investigation and mathematical modelling of such processes. It is also respected, that the
genuine structure (at mesoscopic level) of the porous matter is adequately described not
simply as a percolative system, but rather than a system of percolative-fractal character, and
that this latter fact must also be taken into account at accurate modelling procedures of all
types of transport processes taking place in porous media. In this sense, some pecularities
relevant for coupled transport processes in drying engineering problems and simulatenous
convection-diffusion processes through porous media in general sense are discussed in detail.
Particularly, the presence and crucial role of the Riccati-type differential equation is indicated
in the cases of the solitary wave-, and convection-diffusion processes. It is characteristic for
the Riccati-type ordinary differential equation (ODE), that it is present for decades in certain
well-elaborated areas of fluid dynamics, but some of its basic symmetry properties have not
been applied in detail. Then, completely novel-type solution formulae are proposed for
simultaneous convection and diffusion processes taking place in porous media.
Finally, since solutions of simple parabolic-type partial differential equations (PDEs) related
to uncoupled transport processes also mean existence of physically unacceptable infinitely
large propagation velocities, we intend to eliminate this problem in the present study from the
beginning, since we are well-avare of the fact, that the problem of infinite velocities may be
supressed not only by presence of the macroscopic mechanical convective flows, but also by
de facto always present thermodynamic cross-effects, too. It is also an intention of ours to
demonstrate, that application of the hyperbolic-type PDEs - emanating from the so-called
wave approach of thermodynamics - is not always necessary for succesful eliminating of the
infinitely large propagation velocity problem.
Accordingly, the simplest possible case of a two-component diffusion is discussed in detail,
where the final solution form is expressed by use of the Lommel-type special functions
(earlier widely used in plasma physics, only – within framework of mathematical modelling of
classic-type transport processes) on the base of a simple symmetry assumption about direct
flow-, and cross-flow diffusion coefficients. Finally, some possible future research activity
areas from the point of view the most general type convection-diffusion processes
supplemented by simultaneous chemical reactions are also indicated.
Acknowledgement: The authors acknowledge the support of the MÖB/DAAD Foundation No. 55731 (2014).
9
INFLUENCE OF MASS FLOW CONTROL ON THE PERFORMANCE OF SOLAR
COLLECTORS
P. Vladár, P. Víg
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: Vig.Piroska@gek.szie.hu
The reduction of the environmental pollution and the depletion of the fossil fuels require
increasing the use of renewable energy sources, including the solar energy. The significant
proportion of the domestic hot water consumption can be produced with using solar energy by
solar collectors. The effectiveness of a solar thermal system depends on many factors. Near
the geographical and meteorological conditions the system is greatly affected by the operation,
such as the hot water consumption and control.
In this work the effectiveness of a special control of solar water heating system was studied.
The principle of this control is to maintain flow rate of the solar loop based on the difference
between the temperatures of solar collector outlet fluid and the stored water remains a
required constant value.
For this study, the solar water heating system installed in the Department of Physics and
Process Control, Szent István University, Gödöllő was used. Four models were created using
the TRNSYS software. These models are: models with the current vacuum tube and flat plate
collectors operating with on/off control and also operating with flow rate control used PID
controller.
The systems were examined and compared during the operation under the identical initial and
boundary conditions (equal meteorological data, initial stored water temperature, water
consumptions).
The simulation results can be summarized as follows:
The operating time is practically independent of the control. The rate of the on-off switches is
significantly reduced with using PID controller.
Using the PID control the gathered energy was also larger. Additionally, it was observed that
the collected energy value is higher in case the vacuum tube system compared to the flat plate
collector system. Using the PID control the efficiency of the system and the thermal
stratification of the stored water was significantly improved along with the change of the
on/off control for PID. The energy consumption of the pump is less with using PID control.
The PID controller is the most effective compared to the normal control under the low solar
radiation. In case of PID control the stored water temperature at the end of the day went up to
5-7 degrees higher than case of ordinary control.
During the study the volume of storage tank was 300 l, and there was no hot water
consumption. At one year operation for Budapest weather data with using mass flow control
may be save even 15000-20000 HUF yearly.
The presentation shows the details of the modelling, and summarizes the results of the
simulations.
Acknowledgement: This work was carried out within the project OTKA K 84150.
10
ENVIRONMENTAL INFLUENCE AND IMPACT OF THE NEW DEVELOPED SOLAR
PARKS
S. Bartha1, V. Ursu
1, L. Borotea
2
1ICPE-Institute for Electrical Research, NESL- Department,
Splaiul Unirii 313. Bucuresti, Ro- Romania
Tel.: +40 28 522055 Fax: + 40 28 410804 Email: sbartha@freemail.hu 2Universitatea Babeş Bolyai, Cluj- Napoca, Faculty of Environmental Science and
Engineering, Extension Sf. Gheorghe
In the last period the Romanian Energy market has been enriched with a new energy form,
with the energy provided by solar PV parks. Based on ANERE - Regulatory Authority for
Energy the total installed PV plant capacity today is above 1300 GWp. The Romanian energy
market intends to arrive in 2015 to produce 30 % of the electrical energy by renewable energy
sources. In this way we can enounced that the solar PV energy is on base primary energy
source and in 2013 year in structure of the primary energy sources arrived the 0.85 %. In this
year the total amount of electricity delivered by the producer into national grid was 54.44
TWh, so that PV energy contribution in this energy mix is 0.462 TWh, and the wind energy
4.86 TWh. Base on this ANRE report the Structure of total installed power capacity by type of
technology was as follows:
2594 MW installed power in wind farms;
531 MW installed power in hydro power plants;
66 MW installed power in power plants using biomass, including power plants using
waste and power plants using waste and sludge digester gas from wastewater
treatment plants;
1158 MW installed power in photovoltaic plants.
Base on this date Romania is in a first place in East Europe in the energy production used with
renewable energy sources.
The PV plants can influence the environment, including the land aspects and the land usage
but they have an important role in reducing the CO2 emission.
All of these aspects are presented in this article. The paper also indicates the recycling
procedures of the photovoltaic modules and shows the legal aspects for this process.
In the second part of the study, the actual electricity production is presented by real solar
parks.
The paper indicated the national trends of PV conversion systems in Romania and it compares
this trend with the local investment market.
Finally, the study indicates the environmental impact of the target value from the perspective
of the energy mix established by certain EU directives.
The paper also will be focused to indicate the impact of these solar parks to the biodiversity
present in solar park areas, that will start with one initially evaluation of the biodiversity in
case of these large scale solar parks.
11
ANALYSIS THE PERFORMANCE OF ABSORPTION COOLING SYSTEM
BY SOLAR ENEGY
A. Szilágyi1, I. Seres
2
1Department of Vehicle and Agricultural Engineering, College of Nyíregyháza,
Sóstói u. 31/B., Nyíregyháza, H-4400 Hungary
Tel.: +36 42 599400 /2482 Email: szilagyia@nyf.hu
2Department of Physics and Process Control, Szent István University,
Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: Seres.Istvan@gek.szie.hu
The average temperature in Earth is increased year by year. The summers are very hot and
very strongly for the human body. We are using in this period mainly air-conditioning
systems, which are working with electrical energy (power). This energy comes from the power
plants, especially from heat power plants. In summer this plants give more power and more
emissions. So this emissions generate several environmentally effects, for example global
warming, air pollution, etc.
We can reduce the emissions with the utilization of renewable energy sources. The utilization
of the solar energy is given a good possibility for us, that we can use this energy for cooling.
There are two forms of the solar energy utilization, which are the heat production with solar
collectors and power production with solar photovoltaic cells. By the solar cooling we do not
need energy storage mainly, because the consumption and the heat wave appear in the same
time.
By the solar cooling we are using an absorption system. In this case we are heating the cooler
with solar cells. On the output of the cooler there is a heat exchanger with a fan for the air
conditioning. The studied experimental cooling system was installed at the Department of
Physics and Process Control, Szent István University, Gödöllő, Hungary.
The transfer fluid was water, and propylene glycol. The heating and the cooling performance
depends on following main parameters: the fluid flow rate, the difference of temperatures and
the specific heat of the cooled medium. The cooling system’s performance was better with propylene glycol than water. In the first case the working period was longer and more stable.
According to our measuring the solar cells and collectors are able to ensure the energy needed
directly in the necessary time for the cooler and for the other air conditioning devices, for
example fan and water pump. With this application we can save costs, energy, because we do
not use fossil fuels, and reduce our environmental pollutions and the human effects of global
warming.
Acknowledgement: This work was carried out with the support of the Mechanical Engineering
Doctoral School, Szent István University, Gödöllő, Hungary.
12
INVESTIGATION OF THE EFFECT OF SEALED SURFACES ON LOCAL CLIMATE
P. Weihs1, S. Hasel
1, E. Mursch-Radlgruber
1, C. Gützer1, H. Trimmel
1,
S. Krispel2, M. Peyerl
2
1Institut für Meteorologie, Department für Wasser, Atmosphäre, Umwelt, Universität für
Bodenkultur, Wien, Österreich, Peter Jordan Strasse 82, A-1190 Vienna, Austria
Tel. +43 1 47654 5624 Fax: +43 1 47654 5610 Email: Weihs@mail.boku.ac.at 2Smartminerals, GmbH, Vienna, Austria
Local climate is driven by the interaction between energy balance and energy transported by
advected air. Short-wave and long-wave radiation are major components in this interaction.
Huge differences in temperature (~10°C) between sunlit and shadowed surfaces may result
from the radiation balance. Hence adjusting the grade of reflection of surfaces is an efficient
way to influence this range of temperature. While reflectivity is growing with the amount of
reflected radiation the absorbed radiation is transformed into thermal energy heating the
affected body and giving off heat to the air.
In urban areas the specific geometry of the building structure leads to a larger surface area,
thus the absorbable amount of solar radiation is higher. On the contrary undeveloped areas do
not heat up like urban areas because of the higher amount of shadow and the higher capacity
of evapotranspiration from vegetation. On hot summer days when the heat exchange is on a
low level, buildings begin to heat up and act as a thermal storage system, leading to the well-
known “heat island” effect.
Climate warming at global- and urban-scale enhance this effect, therefore using different
materials for buildings or streets can be considered as an effective method to influence urban
microclimate. Santamouris et al. investigated the influence of albedo of asphalt materials on
air temperature. They found a decrease of surface temperature of 12 °C and of air temperature of 1.9°C - compared to a conventional asphalt surface - above an asphalt surface with a
reflection of 47% in the visible and 71% in the infrared spectral range.
The goal of the present study is the comparison of two urban energy balance models (TEB and
EnviMet) and their output with respect to different building and road surfaces. The models are
used to simulate the air temperature of the local climate for an urban canyon in Vienna. In a
next step thermal stress indices (UTCI, PMV) are calculated based on the simulations. Input
parameters are taken from routine measurements of the radiation balance, of the ground and of
the air temperature and humidity at different heights above the ground and from
measurements of the SW and LW optical properties (albedo, emissivity) from/above 6
different types of sealed surfaces. During this measurement campaign the above mentioned
components were measured over a duration of 4 months above 2 conventional asphalt
surfaces, one conventional concrete and three newly developed concrete surface with
increased reflectances. Measured albedo values amounted to 0.12±0.02 for the asphalt surfaces and to maximum values of 0.56 for concrete.
13
UNUSED ENERGY IN OUR HOMES IN THE FORM OF ELECTROMAGNETIC WAVE
G. Vizi
Institute of Architecture
Szent István University, Thököly út 74., Budapest, H-1143 Hungary
Tel.: +36 1 252 1270 Email: Vizi.Gergely-Norbert@ybl.szie.hu
The main goal of energy production is energy consumption, but energy can also exist in an
unused electric-, magnetic-, and electromagnetic form. According to building biology health
standards regulations that are taking different areas into consideration we must examine our
living space, and new test methods should be developed for new areas.
For measuring electric, magnetic and electromagnetic fields there are sophisticated tools
available. The used manual measurement tools are the following at low frequency: Gigahertz
Solutions NFA 1000, and at high frequency: Gigahertz Solutions HF59B devices. The
computer software used for simulation is CST Microwave Studio.
From the on-site measurements it was found that the majority of homes exceeded the
recommended values of the building biology guidelines and about 50% of them were in the
weak and 50% were in the high anomaly category. Measurements were taken at several points
in every room, following a helical path and were recorded in the floor plan. Areas of extended
stay (e.g. bed) were examined separately. The height of investigation was 1.30 m (except for
beds where it was 0.5 m)
Radiation sources inside of a building can be controlled, outside sources can be shielded by
architectural design and conductive nets. To predict the electromagnetic fields inside a new
building or to calculate shielding the use of a computer software is advised.
CST Microwave Studio was used to examine the effects of the openings in walls and the
shielding of building materials. A small reference building with the outer dimensions of 5.0 m
x 3.6 m x 3.3 m was created in the program. The walls, the roof and the floor consist of brick
and concrete slabs/panels of 30 cm thickness. The characteristics used for these materials in
the simulations are taken from the material library of the above mentioned electromagnetic
simulation software. For simplifying the simulation an electromagnetic plane wave was
chosen. The directions of arrival chosen are all horizontal, which is very common in real
situations, and the angles are 90°, 45°, and -45°. The frequency considered is 1 GHz. Later a door and windows were placed into this reference building and the effects of their size and
positioning were studied.
Measurements in the anechoic chamber at the Electrical Engineering Department of the KU
Leuven University in Belgium are in agreement with the calculated shielding values of the
simulation. The setup involved a 30 cm thick brick wall with the dimensions of 100 cm x 75
cm with a 5 cm x 5 cm or 1.27 cm x 1.27 cm copper net on the back side. The transmitting
Hyperlog antenna was put 140 cm away from the receiving antenna which was 1 cm behind
the wall. In order to decrease the effect of unavoidable diffractions at the edges of the wall a
special technique was used to smoothen the curve of shielding values of raw measurements.
Extra shielding was achieved by mounting copper nets with different grid sizes on the back
side of the brick. An 8 dB attenuation was achieved with a 5 by 5 cm net in case of 1 GHz
radiation, and with a 1.27 by 1.27 cm net in case of 2.4 GHz radiation. The 8 dB attenuation
lowered the level of the electromagnetic fields to the desired building biology level.
14
SPECTRAL MEASUREMENTS IN CONNECTION WITH PHOTOVOLTAIC ENERGY
PRODUCTION
I. Seres, F. Kiss, B. Sipos-Szabó
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: Seres.Istvan@gek.szie.hu
On the campus of the Szent István University, Gödöllő, Hungary a 10 kWp photovoltaic system was constructed, from two different PV technologies, two subsystems of 3,1 kWp from amorphous silicon
DS40 modules (Dunasolar), and a 3,5 kW part of ASE100 modules from polycrystalline (RWE Solar)
technology. The long-time analysis of the energy production of the system showed an interesting
effect, the rate of the power of the different technology subsystems shows a seasonal periodicity, in
the winter time the rate polycrystalline module’s production is higher than in the summer period.
This fact induced a research about the reason of the effect. From the literature two main reasons were
identified, the different temperature dependence and the different spectral behaviour of the modules.
To examine the spectral properties a spectrometer was set up and measurements were started parallel
with the power measurements. In this paper the first results of the spectral measurements are
presented.
The spectral measurements were performed by the USB2000+ VIS-NIR-ES spectrometer, made by
the Ocean Optics company. The system collects the light in an outer dome and transfer the light to the
spectrometer unit through an optical cable. The spectrometer (a single-slit unit where the incoming
light is separated to different wavelength by diffraction on a 50 mm diameter optical slit) is connected
to a computer through an USB port.
Spectrogram of the incident light with the No of incoming photons
The optical slit separates the incoming light by wavelength, and a serial of light sensitive sensors
detects the number of the photons hitting the sensor element during an adjustable time period. For
measuring and analyzing the data, the Overture software (Ocean Optics) were used. To get the power
distribution as a function of the wavelength from the number of photons, the energy carried by a
photon has to be used which is known from the Planck theory.
In the paper the first result of the comparison of the spectral and power data is introduced together
with a small demonstration. In this demonstrational measurement the spectra of the incident light is
changed by colour filters, while the electromotive force of a PV module is measured. It is shown, that
even if the visible part of the incident light is blocked by the filters, the PV module has almost the
same EF as during the total illumination, which demonstrate the infrared sensitivity of the module.
Acknowledgement: This work was carried out within the project OTKA K 84150.
15
SOLAR AIR CONDITIONING
M. Gaucher
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: matthias.gaucher@gmail.com
The term "Solar air conditioning" refers to any air conditioning (cooling) system that uses
solar radiation. This method of air conditioning that can replace the use of fossil fuels has the
main advantage of being able to provide cold when it is hottest, which generally corresponds
to periods when the sun is available. There are several types of air conditioning system such
as solar thermal compression technology, solar open-loop air conditioning using desiccants
and solar closed-loop absorption/adsorption cooling.
The solar thermal compression technology is a passive cooling. Its principle is the installation
of a long length of stovepipe. The air in the pipe is heated creating a suction phenomenon on
the basis of the pipe. By a blade system, the air is forced to form a vortex. Finally, a small
tube is recovering cold air in the centre of the vortex, in that case, the centre of the stove pipe.
Desiccant cooling systems are basically open cycle systems, using water as refrigerant in
direct contact with air. The thermally driven cooling cycle is a combination of evaporative
cooling with air dehumidification by a desiccant, a hygroscopic material. For this purpose,
liquid or solid materials can be employed. The term ‘open’ is used to indicate that the refrigerant is discarded from the system after providing the cooling effect and new refrigerant
is supplied in its place in an open-ended loop. Therefore only water is possible as refrigerant
with direct contact to the surrounding air. The common technology applied today uses rotating
desiccant wheels, equipped either with silica gel or lithium-chloride as sorption material.
Solar closed-loop absorption/adsorption cooling uses solar thermal collectors to provide solar
energy to thermally driven chillers (usually adsorption or absorption chillers). Solar energy
heats a fluid that provides heat to the generator of an absorption chiller, and it is recirculated
back to the collectors. The heat provided to the generator drives a cooling cycle that produces
chilled water. The chilled water produced is used for large commercial and industrial cooling.
The common technologies used for solar closed-loop absorption/adsorption cooling are
ammonia and water, water and lithium bromide and water and lithium chloride for the
absorption. For the adsorption it is water and Silica Gel or methanol and activated carbon.
There are many advantages for the solar air conditioning such as the cold production with
endless energy: solar energy, perfect synchronization between the cooling demand and solar
radiation, very low power consumption compared with those due to a chiller and no polluting
refrigerant, degrading the ozone layer or greenhouse. There are also some disadvantages as the
solar air conditioning dependent on the radiation of the sun, the system only works in day. It is
more suited for companies, local or machines operating only during the day. However it is
possible to store the heat stored during the day in tanks or solar ponds to use the system for
non-sunny periods.
16
ANALYSIS OF SOLAR RADIATION COMPONENTS
T. Carrasquinho
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: tcarrasquinho@gmail.com
The sun is the star in the middle of the Solar System where the Earth is. It is composed mainly
by hydrogen and helium. As it is warm and dense, the heat travels from the inside to the
outside of the star. This heat is transmitted under the form of convection inside the sun and,
when it gets to the surface, it is transformed into radiation.
When the radiation gets to the earth it is attenuated by the atmosphere passing from a potency
of 1368 W/m2 to approximately 1000 W/m
2 in a bright sky. As it has to cross the atmosphere,
the total irradiation can be calculated by adding the direct radiation with the diffused radiation
(where the reflected radiation can be also included). The direct radiation is, as it name says,
the radiation that crosses the atmosphere without suffering any alteration from its original
direction and the diffused radiation is the radiation that, when crossing the atmosphere, hits
molecules. This process is elastic, which means that the light is deviated without any change
in its wavelength. The diffuse radiation depends on how much dust and haze there is in the
atmosphere and is responsible for the different colours the sky can have during the day.
The sun can be approximated to a black body. A black body is an object that absorbs all the
electromagnetic radiation that falls on it and that is why it is called a black body. If it’s in equilibrium, than the black body irradiates as much as it absorbs. According to Stefan-
Boltzmann law, the irradiation per unit of area in a black body depends exclusively on the
temperature of the black body and, as the sun has a temperature of about 5800 K, its peak
stand near the green, yellow and orange colours (between 500 and 600 nm) giving it the
yellowish colour that we can see.
Despite its peak being in the visible light part of the electromagnetic spectrum, the sun also
irradiates infrared and ultraviolet waves, the second ones being much more powerful than the
infrared ones.
17
INTEGRATED USE OF SOLAR ENERGY
B. Cemre Yesillik and I. Farkas
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: bugucemreyesillik@gmail.com
Increase in world population, industrialization, intensive urbanization, the need for human
comfort energy consumption is increasing exponentially. Today the world, their energy needs
from fossil fuels or nuclear power plants and hydroelectric power are met. However, two
problems encountered in the use of these fuels are to go. The first problem that fuels the
possibility of extinction in the near future, and the other in certain areas of industrialization is
largely a result of concentration of environmental pollution resulting from the use of fossil
fuels is increasing. All these reasons research for more efficient use of alternative energy
resources is intensifying.
Among renewable energy resources, solar energy is by far the largest exploitable resource,
providing more energy in 1 hour to the earth than all of the energy consumed by humans in an
entire year. In view of the intermittency of insulation, if solar energy is to be a major primary
energy source, it must be stored and dispatched on demand to the end user. An especially
attractive approach is to store solar-converted energy in the form of chemical bonds, i.e., in a
photosynthetic process at a year-round average efficiency significantly higher than current
plants or algae, to reduce land-area requirements. Scientific challenges involved with this
process include schemes to capture and convert solar energy and then store the energy in the
form of chemical bonds, producing oxygen from water and a reduced fuel such as hydrogen,
methane, methanol, or other hydrocarbon species.
People want to use solar equipment because it is cost effective, resource saving, simple to use
and understand, and there is a logical, direct and unencumbered energy resource in the sun as
it moves across the sky.
18
AUTONOMOUS SOLAR PHOTOVOLTAIC SYSTEM
F.P. Cazarim
Mechanical Engineering
Szent István University, Páter K. u. 1.,Gödöllő, H-2103 Hungary
Email: fred_cazarim@outlook.com
Autonomous systems are production and power consumption systems without connection to
the public grid. They are the ideal solution for locations where, for various reasons, it is not
possible to connect to the network, for systems in motor homes or for boats. Thus, all energy
is produced locally in an environmentally friendly way.
The system is composed of one or more power generators, which are typically photovoltaic
panels that capture the sun's energy. Through a charging regulator electrical power is charged
to the battery, where it is stored until needed. In order to be consumed, the battery power is
removed and converted to direct current (DC) to alternating current (AC). In this way is
possible to use conventional appliances, similarly to the electric energy from the public power
grid.
An autonomous PV system should be designed to the point where it is installed. You should
take into account the solar potential and periods without heat stroke. In addition, a study must
be made possible in the shading photovoltaic panel plane. They are not recommended for
heating water. The power of an electric shower demand a system of generation and storage
that are not viable
Compared with the systems connected to the network, to produce the energy equivalent to the
total annual consumption, the power to be installed is approximately two to three times
higher. In short, the cost of an autonomous system are at least twice higher than the costs of a
system connected to the network. Thus, an independent system must be installed only in the
situation where there is a complete impossibility of connection to the public power grid.
19
ROOF INTEGRATED SOLAR COLLECTORS
G.L. Farias
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Email: gabrielefarias1992@gmail.com
The roof integrated solar panels has been an option to the great demand for the so called
‘green’ homes, which have a need for a great energy-efficiency with the use of a renewable
energy source. The solar energy has such great potential resource but it still is very ignored
when it comes to converting it to different types of energy, such as heat or electricity, mainly
because of the cost of the systems.
The new design of the solar collector integrated with the roof, shows a great potential of
reducing the costs by making tiles already prepared for its porpoise of being an energy
accumulator, this way maximizing the benefits of the free energy it’s generating. For an example I will use the SHARP collector, which is comprised of 18 multicrystaline cells with
one bypass diode per module and are wired together with Onamba C3 quick connect, this
module is designed to replace five standard flat cement tiles. It has a power warranty of 25
years. The design of the integrated systems has also called attention not only for its ‘clean’ energy appeal, but also for its discreet and better looking array, because until recently, most of
the solar panels were rigid modules that were attached to a roof-mounted rack. Using an
integrated roof collector you can also benefit from using your entire roof space for the solely
purpose of being an energy collector, or also have the option of using just a part of it.
Called BIPV (building-integrated photovoltaic), they have several forms of display and that
effects on how much energy it will collect and what will be its payback time. The position it
should be displayed is the angle of the panels and its orientation (south, north), the
environment that the collector is suggested, for an example; a city that has four months of
intense sun is more likely to storage more energy than a city that receives only two months
and is cloudier. For the integrated solar collectors the more common is the display on a
pitched roof, with the sun rays incidence having a great role in the efficiency of the collector.
The photovoltaic panels convert the light directly into electricity, which can be used right the
way in the building or, sometimes when the energy is excessive, exported to the electricity
grid.
20
HYBRID SOLAR SYSTEMS
T. Maltempi
Graduating in Biosystems Engineering Faculty of Animal Science and Food Engineering
University of São Paulo
Av. Duque de Caxias Norte, 225 - CEP 13635-900 - Pirassununga/SP – Brazil
thiago.maltempi@usp.br
The use of renewable forms of energy is growing substantially for years mainly due to concern
with the gradual warming of the planet caused by the release of greenhouse gases. In this
reason, many researchers seek over the years developing and improving renewable energy
production. A good part of these studies were carried out for improvement of photovoltaic
cells and solar collectors.
Nowadays, both solar collectors as photovoltaic cells reached a satisfactory level of evolution
when we think of efficiency values, still being the most efficient the solar collectors, since
they are simpler and have been studied for a longer period. The photovoltaic modules have
efficiency between 10% and 20% depending on their quality. One of the main factors against
the increase in efficiency is precisely the high temperatures which the modules are exposed,
the higher the temperature is lower the efficiency of the system. So, one of the ways to
increase the efficiency of a PV module is by cooling through the use of a hybrid system
combining photovoltaic panels and solar thermal collectors. It is resulting in production of
electricity and heating a liquid or a gas responsible by decreasing temperatures in PV
modules, and consequent utilization for heating. The PV/T solar systems can be used in
domestic and industrial sectors with high efficiency.
The hybrid systems can be of three types: PVT air-cooled, water-cooled and PV/T
concentrator. Each is constructed of different ways in to seek the best design for better
efficiency energetic. PV/T water-cooled systems are the most efficient, while PV/T air-cooled
can be integrated in the constructions and PV/T concentrator require a constant radiation flux
across the photovoltaic cells. Studies reveal that the total efficiency of a Hybrid PV/T systems
can range from 50% -80%.(e.g. Bergene and Lovvik, 1995).
21
CONCENTRATED SOLAR COLLECTORS
E. Tsuchida
Environmental Engineering
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Email: eltontsuchida@gmail.com
Modern society has undergone several changes, we observe intense discussion and uncertainty
in the future energy world. In this context, renewable energy use has expanded, and solar
energy is presented as an excellent alternative energy.
The changes and environmental impacts have driven research, so that there is a growing
search for new technologies to enable the adoption of renewable and less impactful on the
environment. The example of these alternatives, solar energy, a clean and renewable source
has gained increasing prominence in the world energy market. An important technology for
the use of this source is the Concentrated Solar Power whose basic foundation using reflective
surfaces to capture solar energy incident over a larger area so as to focus it on a smaller area, it
can raise the temperature, allowing the generation of thermal energy and electric.
Among the different concentrated solar technologies, we can highlight: the parabolic
cylindrical, the Fresnel concentrator, the solar dish and the solar tower.
The cylindrical parabolic is constituted by concave mirrors and absorber tube, in which a
thermal fluid circulates. The parabolic concentrators are the most mature technology solar heat
generation and allow the heating fluid temperatures up to 400 °C.
The Fresnel concentrator has an action similar to the cylindrical concentrator, though the
former have a fixed absorber tube and are formed with flat dishes. The Fresnel designs are
still not a mature technology and most of the plants in the world are pilot plants, with a few
commercial low power plants (1 to 5 MW) in operation in the USA and Spain.
The solar dish consists of a structure that receives the mirrors, a Stirling engine and generator.
The heat directs sunlight to the receiver, which transfers heat to the working fluid and can
reach 1500 °C temperature range, triggering a Stirling-cycle engine coupled to a generator.
The solar tower, also known as central receiver systems, these are formed by mirrors called
heliostats. These systems use thermal energy to produce electricity from steam to high
pressure.
Each concentration method is capable of producing high temperatures and thermodynamic
energy efficiencies also high, but will vary in order to track the sun and focus the light. Due to
new innovations in technology, solar thermal concentration is becoming more and more cost-
efficient level.
22
GENERAL CONSIDERATIONS ON SOLAR VACUUM TUBE COLLECTORS
F. Leonardo
Department of Environmental Engineering
Federal University of Sergipe, Av. Marechal Rondon, Jardim Rosa Elze- 49100-000, Brazil
Tel.: +36 30 7351643 Email: leonardufonseca@gmail.com
Evacuated tube collectors have been spreading more intensely on the solar energy market. Its
advantages over the common flat plate collectors and its larger range of applications have
been resulting in this growing.
The evacuated tube collectors based generally on a vacuum sealed tube with a solar absorber
coating inside. The tubes, which are made of special glass, permit the entrance of solar
radiation and its conversion in heat through an absorber surface. The vacuum envelope in the
system reduces convection and conduction losses. The combination of the highly efficient
absorber coating and the vacuum insulation provides the coating can be well over 200°C,
proper temperature to use in solar heating.
Its geometry permits the exposure of most of the absorber area for a long period of the day,
increasing its efficiency in low angles as early and late in the day. Moreover, during cold days
they also continue receiving solar radiation even with cold temperatures outside the glass
tubes. However, some cares must be taken where heavy snowfall happens often to permit melt
of snow and heavy frost.
Following the general principle of vacuum tubes, several different systems have been
designing by researchers and manufacturers. The heat pipe vacuum tubes uses liquid-vapour
phase change to transfer heat at high efficiency. In this case, the pipes are sealed by copper
and are attached to a black copper absorber plate and with a heat exchanger on the top of each
tube. These heat pipes contain a small amount of fluid that follow a cycle of evaporation and
condensation that is responsible for heat the fluid that flows in the manifold.
Another kind of vacuum tube collector is the direct flow tubes. In this configuration, a single
ended metal absorber pipe is assembled in the glass vacuum tube through a glass-to-metal
seal. A central tube is used to transport the main fluid to the bottom of the metal absorber
tube. So, the fluid flows up the space between the central tube and the larger metal absorber
tube. An alternative configuration of this design is to use a U-shaped tube. The tubes of these
kinds of configurations are connected in series.
Other variations are commercialised by some manufacturers like the all-glass and the
integrated compound parabolic collectors that provides better efficiency than the others.
In relation to the costs, the acquisition of vacuum tube collectors can be more expensive than
flat plate collectors. On the other hand, installation and maintenance costs might be cheaper.
In general, this collector have several advantages such as its benefits mainly in cloudy and
cold conditions nevertheless the costs still influence the market. Its application in uses that
need high temperatures like solar heating is an important consideration and with the new
researches in new configurations and consequently higher efficiency, they can increasingly
establish on the market.
23
SOLAR HEATED GREENHOUSES
M. Okado
Environmental Engineering Course
CAPES – Science Without Borders
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
For a long time, man depended of seasonality for producing their food. In purpose of
extending the crop season, many techniques were developed intending to simulate an adequate
weather condition for growing plants. In this context emerged the first greenhouses. New
technical developments allowed growing crops even during the hardest winters, by gas heating
systems and insulation techniques. However, as a result of increasing fossil fuels prices and
environmental problems caused by carbon dioxide emissions and other pollutants, different
solutions were created intending to be sustainable and rentable, producing food with a good
price in a clean way. For this reason, the passive solar heated greenhouses were developed.
The main objective of this paper is to present a definition of solar heated greenhouses,
showing the building basic principles, its main components and its applicability as a
sustainable solution for cultivating crops during the winter.
Solar heated greenhouses have to be installed to receive the higher amount of solar energy
available. The conventional greenhouses have its axis running from south to north. This
orientation allows plants to receive a uniform solar energy. SHG is oriented with its roof
running west-east, allowing higher radiation entrance with a poor distribution. In this kind, the
south face of the building, including the roof, is glazed in order to get a great amount of
radiation while the other walls are insulated to prevent heat losses
Glazed materials used in the greenhouse have to allow the highest light penetration as possible
and, at the same time, minimize the heat losses. Furthermore, vegetable growth requires that
these materials should allow the entrance of natural spectrum of light. Glasses with rough
surface, double layer plastics and fiberglass are materials that allows a diffuse light
penetration, while clear glass transmits a direct light.
Intending to maintain the greenhouses warmed during the night or cloud days, the thermal
energy coming from sunny days must be stored. The common methods utilized to store
thermal energy include the disposition in line of concrete or gallons filled with water in the
north wall of the greenhouse so that this wall receive solar energy during the day and disperse
this energy slowly during the night.
The demand for sustainable solutions has been increasing year after year. The solar heated
greenhouses emerged as a perfect example of rentable and sustainable alternative for cultivate
food during all the year
Use these greenhouses for growing crops can result in a greater food offer during the winter,
when the availability is low because of climate adversities. Greater availability of food can
also reduce importations amount and, consequently, a reduction in the food prices, since the
food is a national product.
24
PASSIVE SOLAR APPLICATIONS
S.E. Matsumoto
Department of Physics and Process Control
Szent István University, Páter Károly u. 1, Gödöllő, Hungary
Email: susan.emi.matsumoto@gmail.com
Recent years, many countries and organizations have paid more attention in environmental
protection. Ozone depletion, greenhouse effect, global climate changes and global warming
are the main issues. Environmental protection laws are being implemented in a great number
of countries. In this scenario, creative, cheap and efficient ways to use energy to our advantage
are being created and the passive solar design is one of them.
As a cheap and easy system to be applied, passive solar design is the oldest technology
implemented to utilize solar energy as a way to take as much energy as possible, make life
more comfortable and spend less electricity and artificial heating. Therefore, it has become
very popular and the development of the passive solar applications is continuous.
After the implementation, passive solar system use only natural process. The distribution of
the heated air is done by radiation, conduction and convection. Not using any mechanical
devices during the operation – those make any system more expensive and complicated – is
one of the main advantages of passive solar application. Also, it is important to say that
related with this benefit, we have another one, which means there are no moving parts in
whole system.
Currently, some companies are using the system in a very clever way. Besides reducing the
electricity and heating bills, they are offering more comfortable and friendly environment and
as a result the productivity of all employees increases substantially. However the main point is
that they use this advantage as a marketing of the company. They show up a “green” outlook and this attracts many looks of those who have interests in environmental perspectives.
With all these advantages and five relevant items - site location, orientation, thermal mass,
seasonal shading and distribution- it is possible to do a good passive solar implementation.
25
RENEWABLE ENERGY SCENARIO
V. de Carvalho Silva
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 70 2406058 Email: viniciuscs1992@gmail.com
Nowadays, in all the world the demand for energy is increasing and also its price are always
very high and unstable. The high level of Greenhouse gas emission became a big problem in a
few decades and one of the main emitters is the energy sector.
Beside, the natural reserves of fossil fuels are concentred in a few suppliers countries, many
times causing conflicts and wars. In 2012, the consumption of fossil fuels was 87%, showing
the need to change energy sources. Considering all these problems, renewable energy became
a great alternative to change this panorama.
Renewable energy offers a lot of options for the growing demand of energy, mainly in the
context of economic development which takes account the social and environmental issues, as
well.
Brazil has a big range of options of natural sources for renewable energy, for example, solar
power, hydraulic energy, ethanol, biodiesel and wind power. Because of this, Brazil has a
strategy aiming to satisfy the demand for energy. Brazil is located in a favourable
geographically position, between the tropics, which means that Brazil has a high level of UV
rays incident and a wet climate which is favourable to the big rivers and crops of sugar cane
and for biodiesel raw materials.
Although Brazil has a big potential in production of renewable sources in comparison to the
rest of world, it is a little late, for instead, Brazil is the 3rd
in capacity of production of solar
energy, but it is just the 22nd
in generation of solar energy.
Considering that, this study I will show you the scenario of renewable energy in Brazil in
comparison to the rest of the world.
26
SOLAR ENERGY SCENARIOS
D. Silveira Costa
Federal Technological University of Paraná
Brasil Avenue, n° 4232, CEP 85884-000 - Postal Code 271 - Medianeira - PR - Brazil
Tel: +55 (45) 3240-8000 - Fax : +55 (45) 3240-8101 Email:diogocosta16@hotmail.com
Developing countries are responsible for the large increase in energy demand, because to
continue growing they require energy for their industries, transport systems and services.
However both developed countries and developing countries are still very dependent on non-
renewable energy sources such as coal, oil and gas. In this scenario, renewable energy such as
solar energy, wind energy, thermal energy, biofuels emerge as a very interesting option and
can fully become economically attractive.
Some studies show that developing countries, such as Brazil, investment in renewable
energies, including solar energy, may become an important part in the energetic matrix within
a few years. According to Pereira et al. (2006) the use of solar energy in Brazil could bring
benefits in the long term: to bring energy to remote regions where conventional modes of
energy are expensive to get there and minimize energy production problems during drought
periods. But today Brazil faces some problems to implement a greater number of solar power
plants, this is mainly because of the lack of technological knowledge, leading to a high cost of
implementation and generation of energy from the sun. However some projections show that
within 15 years Brazil has the potential to grow its energy production through solar power
plants. Investments in local technologies and support from government may cause the costs
are lower and so the solar energy becomes competitive in the Brazilian energy market.
In the world scenario solar energy has been increasingly important for the energetic matrix.
The continents that have more invested in this sector are Europe, Asia and North America.
The European continent nowadays has the highest energy production capacity from the sun,
but some research shows that within a few years this could change and Asia can become the
first continent in solar power generation, mainly by high invested from China and Japan in
recent years.
According to Renewable Energy Policy Network for the 21th century Asia added 22.7 GW to
end 2013 with almost 42 GW of solar PV in operation. China alone accounted for almost one-
third of global installations, adding a record 12.9 GW to nearly triple its capacity to
approximately 20 GW. According to World Energy Outlook 2014 the investment sum in
solar PV only in Asia will reach more than 400 billion dollars by 2035.
27
ENERGY INTENSITY BETWEEN COUNTRIES
W.F. Foletto
Science Without Borders, CAPES Foundation, Ministry of Education of Brazil
Brasilia-DF, Zip Code 70 040-020
Universidade Federal de Santa Maria
Av. Roraima, 1000 - Camobi, Santa Maria - RS, 97105-900, Brazil
Tel.: +36 70 5084613 Email: wagner.farret@gmail.com
Energy intensity is a measure of energy efficiency associated with the economy of a country. It
is calculated by the total amount of energy consumed in that country divided by its gross
domestic product and can be represented, for example, in megajoules per dollar.
Over the past 30 years energy intensity has been declining since the countries are aware that
they should increase the GDP without increasing power consumption with the help of uses of
technologies with low power consumption. But in 2010 the energy intensity increased by 1.35
percent.
Between 1981 and 2010, global energy intensity decreased by about 20.5 percent, or 0.8
percent per year. During this period of decline, most developed countries restructured their
economies and energy-intensive heavy industries accounted for a shrinking share of
production
The report notes that energy efficiency throughout the world had been increasing steadily until
recently. Between 2004 and 2008, global energy intensity experienced its biggest drop in 30
years, with an average annual rate of decline of 1.87 percent.
In addition to technological advances, price developments play a key role in determining
overall energy usage. The world oil prices more than tripled between 2004 and 2008, the
fastest increase since the oil crisis of the 1970s that contributed to the sharp decline in energy
intensity during this period. But after the second half of 2008, when international oil prices
fell 75 percent, the overall energy intensity began to rise.
Energy intensity is declining in many developed countries, including the United States,
Germany and Japan. The most drastic declines in industrial countries have occurred in the
United States and Germany. Overall, China may have made the most progress worldwide,
with a decline of 65 percent in energy intensity in the past 30 years.
For example China has developed various alternatives for the production of energy, such as
solar panels fields, hydro construction. What are cleaner energy sources and thus reduce its
energy intensity. China has the plan reduce 20% of its energy intensity by 5 years.
28
SOLAR HEATING OF OPEN-AIR SWIMMING POOLS
L. Lamb, I. Farkas
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: luizaslamb@gmail.com
All over the world swimming pools have been used for recreation, practical of sports and
medical uses. The swimming season coincides with the time of the highest solar radiation.
Commonly at latitudes in central Europe open-air pools are operated from the beginning or
middle of May until the middle of September. During this period approximately 65-75% of
the annual solar radiation occurs. Use of solar heating extends the swimming season and
reduces monthly fuel bills from conventional heating without depleting non-renewable fossil
fuels. In the present work the utilization of solar unglazed collectors for heating open air
swimming pools are studied.
Temperature level required is relatively low, at 18-25 °C, permitting the use of unglazed collectors. Unglazed collectors are generally made of less expensive polypropylene absorbers
and do not have insulate collector box. The area needed for collectors should equal at least
one half of the pool’s surface area. The absorber is suitable for a diversity of roof forms and
can easily be adapted to slight curves.
Plastic absorbers can be designed in two different ways. The tube absorber is the simplest
design and consists of small tubes arranged in parallel and connected together either with
intermediate webs or by retainers at a given spacing. It can easily circumvent obstructions
such as chimneys or roof lights. In the case of flat absorber, the channels are linked together
structurally. This produces plates of different dimensions with a smooth surface. It has the
advantage that there are no grooves in which dirt or leaves can accumulate and solidify.
The pool water circulates directly from the collector to the swimming pool by a pump made
from corrosion resistant materials. Therefore, no storage tank neither heat exchanger are
needed. The solar system is part of the circuit used to filter the pool water.
Another important component of the system is the control unit. It consists of a pool return
temperature sensor, impeller flow meter, absorber temperature sensor, solar radiation sensor,
pool supply temperature sensor and pool return temperature sensor. A swimming pool
absorber system uses principle of temperature difference control. For switching on the
absorber circuit pump, the absorber temperature is compared with the pool return temperature.
For switching of the system, the supply temperature is compared with the pool temperature.
To decrease evaporation losses, which accounts for 30 to 50 percent of all heat lost from a
swimming pool, a swimming pool cover must be used. Other factors affect the collector
efficient, such as wind on the collector and shadow on the collector. These factors can be
easily removed during the installation, taking care to not put the collectors in a shadow area
and use a wind protector if the area is susceptible to strong wind.
Solar heated swimming pool systems are a mature and established technology. Manufacturers
have produced and sold solar heated swimming pool systems for decades already and due to
continuous innovation products that work effectively are supplied.
29
GRID-CONNECTED PHOTOVOLTAIC SYSTEMS
M. Marzec
Faculty of Mechanical Engineering and Computer Science
Częstochowa University of Technology, al. Armii Krajowej 21, 42-201 Częstochowa, Poland
Tel.: +48 73 0000 975 E-mail: marzecm93@gmail.com
Photovoltaics (PV) or solar cells as they are often called, are semiconductor devices that
convert sunlight into direct current (DC) electricity. Groups of photovoltaic cells are
electrically configured into modules and arrays. With the appropriate power conversion
equipment, photovoltaic systems can produce alternating current (AC) compatible with any
conventional appliances.
Grid-connected photovoltaic systems range from small residential and commercial rooftop
systems to large utility-scale solar power stations. A rooftop photovoltaic power station, or
rooftop photovoltaic system, is a photovoltaic system that has its electricity generating solar
panels mounted on the rooftop of a residential or commercial building. Rooftop mounted
systems are small compared to gound-mounted photovoltaic power stations with capacities in
the range of megawatts. Rooftop photovoltaic systems on residential buildings typically
feature a capacity of about 5 to 20 kilowatts, while those mounted on commercial buildings
often reach 100 kilowatts or more. A photovoltaic power station, also known as a solar park,
is a large scale photovoltaic system designed for the supply of power into the electricity grid.
They are differentiated from most building-mounted and other decentralised solar power
applications because they supply power at the utility level, rather than to local users. They are
sometimes also referred to as solar farms or solar ranches, especially when sited in agricultural
areas.
Residential grid-connected photovoltaic power systems which have a capacity less than 10
kilowatts can meet the load of most consumers. They can feed excess power to the grid where
it is consumed by other users. The feedback is done through a meter to monitor power
transferred. Photovoltaic wattage may be less than average consumption, in which case the
consumer will continue to purchase grid energy, but a lesser amount than previously. If
photovoltaic wattage substantially exceeds average consumption, the energy produced by the
panels will be in excess of the demand. In this case, the excess power can yield revenue by
selling it to the grid.
Maintenance of a grid-connected photovoltaic system is generally limited to ensuring that
shade from trees or other obstacles does not become a problem and occasionally checking the
panels for dirt and, when necessary, cleaning them with water.
There are photovoltaic panels delivering power today that were installed more than 30 years
ago. Photovoltaic is an established technology and with no moving parts it offers reliable,
long-term energy production. Most of the photovoltaic panels are guaranteed to produce at
least 80% of their rated power after the warranty time, which is usually 20-25 years.
30
HYBRID RENEWABLE ENERGY SYSTEMS
D. Suleimenov
Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: daniyar34@mail.ru
The rapid industrialization over the past three decades due to globalization, inventions in new
technologies and increased household energy consumption of the urban population has
resulted in the unprecedented increase in the demand for energy and in particular electricity.
This has led to a huge supply–demand gap in the power sector. The scarcity of conventional
energy resources, rise in the fuel prices and harmful emissions from the burning of fossil fuels
has made power generation from conventional energy sources unsustainable and unviable. It is
envisaged that this supply–demand gap will continue to rise exponentially unless it is met by
some other means of power generation. Inaccessibility of the grid power to the remote places
and the lack of rural electrification have prompted for alternative sources of energy.
Hybrid Renewable Energy Systems (HRES) is composed of one renewable and one
conventional energy source or more than one renewable with or without conventional energy
sources, that works in stand-alone or grid connected mode. HRES is becoming popular for
stand-alone power generation in isolated sites due to the advances in renewable energy
technologies and power electronic converters which are used to convert the unregulated power
generated from renewable sources into useful power at the load end. The important feature of
HRES is to combine two or more renewable power generation technologies to make best use
of their operating characteristics and to obtain efficiencies higher than that could be obtained
from a single power source. Hybrid systems can address limitations in terms of fuel flexibility,
efficiency, reliability, emissions and economics. Types of HRES: Geothermal + Solar PV;
Biomass + Solar CSP; Solar PV + Fuel Cell; Wind + Solar PV; Biodiesel + Wind; Wind +
Pumped Hydro + Solar PV.
Hybrid renewable systems can provide a steady community-level electricity service, such as
village electrification, offering also the possibility to be upgraded through grid connection in
the future. Furthermore, due to their high levels of efficiency, reliability and long term
performance, these systems can also be used as an effective backup solution to the public grid
in case of blackouts or weak grids, and for professional energy solutions, such as
telecommunication stations or emergency rooms at hospitals.
Nowadays we have the main HRES problems: the poor efficiency of solar PV; high
manufacturing cost leads to an increased payback time; energy losses involved in power
electronic; the low life-cycle of storage devices and etc. Thus the researchers and engineers
need to find solutions to address the above mentioned problems. Future research and
development efforts can enhance the use of renewable energy sources. Improved technology
and demand for renewable energy can help in reducing the cost to an extent comparable with
conventional energy. Effective and optimum use of the energy sources in stand-alone systems
can help in meeting the energy demands of remote, inaccessible areas and make them self -
sufficient. Government can provide carbon tax benefits to promote the use of renewable
energy. More incentive based policies promoting the establishment of renewable power plants
should be rolled out by the Government.
31
CHARACTERIZATION OF TWO TYPE PHOTOVOLAIC MODULES
USING MATLAB-SIMULINK
D. Rusirawan 1, N.I. Muhlis
1 and I. Farkas
2
1Department of Mechanical Engineering, Institut Teknologi Nasional (ITENAS) Bandung
Jl. PKHH Mustapa No. 23 Bandung 40124 Indonesia
Tel.: +62 22 7272215 Fax: +62 22 7202892 Email: danir@itenas.ac.id 2Department of Physics and Process Control
Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: Farkas.Istvan@gek.szie.hu
One of the promising renewable energy resources is solar energy, which can be converted into
the electrical energy through the photovoltaic system (direct) or through the concentrated solar
thermal (indirect).
In the photovoltaic system, relations between current, voltage and power generated by system
can be illustrated by photovoltaic characteristics, and it can be developed through
experimentally and theoretically by the simulation.
In this research, software based MATLAB-Simulink in order to characterize of the
photovoltaic modules at different of irradiation and temperature have been created, using
single diode model. By using this software, beside need of the PV module specification at
Standard Test Condition (STC), which issued by PV producer, we only need data of
irradiations and temperatures, as an input parameters. Two types of photovoltaic technologies
i.e. crystalline technology and thin film have been used as an object of simulation.
The simulation results showed that the characteristic based on this software have similar
tendency with simulation results with PV*Sol software package, which has investigated in
previous research, thus it can be concluded that the model used by PV*Sol was the same with
model used in this research, i.e. the single diode model.
Acknowledgement: This work was supported by the project OTKA K 84150.
32
RENEWAL OF A DATA LOGING, MONTORING AND CONTROL SOFTWARE IN
LABVIEW IN CONNECTION WITH A DATABASE SERVER DEVELOPMENT
J. Tóth and J. Buzás
Department of Physics and Process Control
Szent István University, Páter K. u. 1.,Gödöllő, H-2103 Hungary
Tel.: +36 28 522055 Fax: + 36 28 410804 Email: Buzas.Janos@gek.szie.hu
In the Department of Physics and Process Control several solar energy equipment were
developed for different use of solar energy. This application relates to a data acquisition,
monitoring and control system.
The used data acquisition (DatAcq, Bíró, 1996) software framework is a real 32-bit
application it was developed in C for Windows 95 OS in the second half of nineties.
As mentioned the old software was made for, at least, 5-generation old operating system, so it
uses out-of-date libraries which means it’s nearly impossible to recompile the source code, consequently it cannot be modified. In contrast the LabVIEW is widely supported, ergo the
upcoming updates on the operating system won’t take an effect. The source code is easier to
read, even for a not-programmer person, so, in the future the arising changes can be made with
ease. The program is working, but it has not got all the features of the old one. It can:
- read the output of the sensors,
- save the data to a database server,
- draw chart from the measured data.
The old method of saving the data was to store it in local files that were shared over the
network. The problem occurred when multiple users tried to read the same file from the
measuring PC or from the network. To resolve this problem we use SQL server to complete
this task. The benefits are:
- multiple users can read the data, simultaneously,
- the data can be exported arbitrary file formats,
- no need for local access,
- adjustable data access for the users,
- possibility to connect it to the internet.
The software of the server is cross-platform, which means it can be run in other operating
systems (Linux, MacOS) without changes. We planning to add a computer to the system
(driven by Linux), that runs only the server, this way the measuring PC can be disencumbered.
The user side of the system is a PHP-driven webpage, it uses standard HTML elements for the
basic operations, and some JavaScript code, that allows the dynamical ones. In this interface,
users and devices can be added, and data can be exported.
In the future we plan to add several functionalities to the system, which are:
- initialization step at the start of the measurement,
- real-time chart drawing on the webpage,
- system-state indicators in the webpage,
- user friendly design.
Acknowledgements:This work is carried out with the support of OTKA K 84150 project.
33
20th
WORKSHOP ON ENERGY AND ENVIRONMENT
December 4-5, 2014, Gödöllő, Hungary
List of participants
Bálint, Á. Óbuda University, Institute of Environmental Engineering
Budapest, Hungary
Bartha, S.
Research Institute for Electrical Engineering
ICPE - New Energy Sources Laboratory
Bucharest, Romania
Borotea, L.
Universitatea Babeş Bolyai, Cluj- Napoca,
Faculty of Environmental Science and
Engineering, Ext. Sf. Gheorghe, Romania
Buzás, J. Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Carrasquinho, T.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Carvalho Silva, V.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Cazarim, F.P.
Mechanical Engineering
Szent István University, Gödöllő, Hungary
Cemre Yesillik, B.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Farias, G.I.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Farkas, I.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Foletto, F.W.
Science Without Borders, CAPES Foundation,
Ministry of Education of Brazil
Gaucher, M.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Gottschalk, K.
Leibniz-Institut für Agrartechnik Potsdam-
Bornim (ATB), Potsdam, Germany
Gützer, C. University of Applied life sciences,
Inst. of Meteorology, Vienna, Austria
Hasel, S.
University of Applied life sciences,
Inst. of Meteorology, Vienna, Austria
Kiss, F.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Kosztolányi, R. Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Krispel, S.
Smartminerals, GmbH,
Vienna, Austria
Lamb, L.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Leonardo, F.
Department of Environmental Engineering
Federal University of Sergipe, Brasil
34
Maltempi, T.
Graduating in Biosystems Engineering Faculty
of Animal Science and Food Engineering
University of São Paulo, Brasil
Marzec, M.
Faculty of Mechanical Engineering and
Computer Science
Częstochowa University of Techn., Poland
Matsumoto, S.E.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Mellmann, J.
Leibniz-Institut für Agrartechnik Potsdam-
Bornim (ATB), Potsdam, Germany
Mészáros, Cs.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Muhlis, N.I.
Department of Mechanical Engineering
Institut Teknologi Nasional (ITENAS)
Bandung - West Java , Indonesia
Mursch-Radlgruber, E.
University of Applied life sciences,
Inst. of Meteorology, Vienna, Austria
Nagy, N.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Okado, M.
Environmental Engineering Course
CAPES – Science Without Borders
Szent Istvan University, Gödöllő, Hungary
Peyerl, M.
Smartminerals, GmbH,
Vienna, Austria
Rusirawan, D.
Department of Mechanical Engineering
Institut Teknologi Nasional (ITENAS)
Bandung - West Java , Indonesia
Scaar, F.H.
Leibniz-Institut für Agrartechnik Potsdam-
Bornim (ATB), Potsdam, Germany
Scaar, H.
Leibniz-Institut für Agrartechnik Potsdam-
Bornim (ATB), Potsdam, Germany
Seres, I.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Silveira Costa, D.
Federal Technological University of Paraná
Brasil
Sipos-Szabó, B. Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Suleimenov, D.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Szabó, I. Faculty of Mechanical Engineering
Szent István University, Gödöllő, Hungary
Szilágyi, A. Department of Vehicle and Agricultural
Engineering, College of Nyíregyháza, Hungary
Tóth, J. Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Trimmel, H.
University of Applied life sciences,
Inst. of Meteorology, Vienna, Austria
Tsuchida, E.
Environmental Engineering
Szent István University, Gödöllő, Hungary
35
Ursu, V.
Research Institute for Electrical Engineering
ICPE - New Energy Sources Laboratory
Bucharest, Romania
Víg, P. Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Vizi, G.
Institute of Architecture
Szent István University, Budapest, Hungary
Vladár, P.
Department of Physics and Process Control
Szent István University, Gödöllő, Hungary
Weigler, F.
Leibniz-Institut für Agrartechnik Potsdam-
Bornim (ATB), Potsdam, Germany
Weihs, P.
University of Applied life sciences,
Inst. of Meteorology, Vienna, Austria
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