SZENT ISTVÁN UNIVERSITY GÖDÖLLŐfft.szie.hu/EE 2014_Book printed.pdf · SZENT ISTVÁN UNIVERSITY...

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

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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


Institute for Environmental Engineering Systems

Szent István University

Gödöllő, Páter K. u. 1. H-2103 Hungary

E-mail: [email protected] Tel: +36 28 522055 Fax: +36 28 410804

http://fft.szie.hu/ee2014.html

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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


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

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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

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TOWARDS TO THE THIRD GENERATION PHOTOVOLTAIC TECHNOLOGIES

I. Farkas


Szent István University, Páter K. u. 1., Gödöllő, H-2103 Hungary

Tel.: +36 28 522055, Fax: + 36 28 410804, Email: [email protected]

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: [email protected] 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.

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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



Tel.: +36 28 522055 Fax: + 36 28 410804 Email: [email protected]

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.


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: [email protected] 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: [email protected]

2Department of Physics and Process Control, Szent István University,

Páter K. u. 1., Gödöllő, H-2103 Hungary


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: [email protected] 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: [email protected]

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




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.


15

SOLAR AIR CONDITIONING

M. Gaucher




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




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




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: [email protected]

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




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

[email protected]

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



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: [email protected]

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


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


Szent István University, Páter Károly u. 1, Gödöllő, Hungary


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




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:[email protected]

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


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




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: [email protected]

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




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: [email protected] 2Department of Physics and Process Control



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


Szent István University, Páter K. u. 1.,Gödöllő, H-2103 Hungary


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


Carrasquinho, T.



Carvalho Silva, V.



Cazarim, F.P.

Mechanical Engineering


Cemre Yesillik, B.



Farias, G.I.



Farkas, I.



Foletto, F.W.

Science Without Borders, CAPES Foundation,

Ministry of Education of Brazil

Gaucher, M.



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,


Kiss, F.



Kosztolányi, R. Department of Physics and Process Control


Krispel, S.

Smartminerals, GmbH,

Vienna, Austria

Lamb, L.



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.



Mellmann, J.



Mészáros, Cs.



Muhlis, N.I.

Department of Mechanical Engineering

Institut Teknologi Nasional (ITENAS)

Bandung - West Java , Indonesia

Mursch-Radlgruber, E.



Nagy, N.



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.



Scaar, H.



Seres, I.



Silveira Costa, D.

Federal Technological University of Paraná

Brasil

Sipos-Szabó, B. Department of Physics and Process Control


Suleimenov, D.



Szabó, I. Faculty of Mechanical Engineering


Szilágyi, A. Department of Vehicle and Agricultural

Engineering, College of Nyíregyháza, Hungary

Tóth, J. Department of Physics and Process Control


Trimmel, H.



Tsuchida, E.

Environmental Engineering


35

Ursu, V.

Research Institute for Electrical Engineering

ICPE - New Energy Sources Laboratory

Bucharest, Romania

Víg, P. Department of Physics and Process Control


Vizi, G.

Institute of Architecture

Szent István University, Budapest, Hungary

Vladár, P.



Weigler, F.



Weihs, P.



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