Category Archives: EuroSun2008-9


In the network are two universities: Faculty of Architectures and Urbanism of Sao Paulo University (FAU-USP) and Federal University of Pernambuco, Recife.

The University of Sao Paulo undertook a study on the ambient comfort conditions and energetic efficiency in social flats [1]. After the survey, cooperation was established with the Company of Housing of Sao Paulo Municipality — COHAB, having been simulated, by request of COHAB, the replacement of fibro concrete tile by clay tile, wall of concrete blocks by brick walls, application of thermal insulation on the roofs and the increase of solar gain areas (window area). The research team

Подпись: Fig. 5. Apartment simulated and results.

image138simulated also the solar protection by adopting solar shading devices on the transparent areas. The increase of window areas was studied in terms of thermal-energetic aspects, also in terms of day lighting [2].

In Brazil, the electrical consumption reduction in social housing can be achieved by the reduction of energy consumption for bathing hot water, actually is around 30% of the Brazilian mean consumption. With the adaptation of solar collectors on the roofs is expected a reduction of 50% in this final use, which corresponds a 15% of final reduction in the electrical energy bill of each habitation.

The University of Pernambuco identified some buildings incorporating bioclimatic concepts:

Подпись: I 28,3 Подпись: 28,5 BR 101 image141 Подпись: 29,1 ZEIS Подпись: 27,8

Ministerio da Educa? ao e Cultura (Rio de Janeiro), Santo Antonio (Recife) Building, Superintendencia do Desenvolvimento do Nordeste, Centro de Tecnologia da Rede Sarah (Salvador e Fortaleza) e o Nhcleo de Pesquisa Multidisciplinar da UFAL [1]. Since 2006 that have been analyzing the bioclimatic design contribution and correlating urban planning and urban climate, Fig.6..

Fig. 6. Temperature profile in Recife.

Doctoral Program in Sustainable Energy Systems

The Doctoral Program in Sustainable Energy Systems of the Faculty of Sciences of the University of Lisbon (http://mit. fc. ul. pt) was developed in the context of the MIT-Portugal Program, in collaboration with the Massachusetts Institute of Technology (MIT), the Oporto University (FEUP), the Technical University of Lisbon (ISEG and IST) and the University of Coimbra. The first year of the doctoral program conjugates formal postgraduate teaching with development of individual research projects. Some of the courses of the 4th and 5th years of the Master Degree

program serve as optional disciplines for the Doctoral Program in Sustainable Energy Systems of the Faculty of Sciences of the University of Lisbon.

The actual PhD projects are integrated within national and international research projects that are conducted by certified research centres, in particular the SESUL and the CGUL.

Laboratory exercises on photovoltaics at Czech Technical. University in Prague

V. Benda and Z. Machacek

Department of Electrotechnology, Faculty of Electrical Engineering
Czech Technical University in Prague
Technicka 2, 166 27 Praha 6, CZECH REPUBLIC
E-mail: benda@fel. cvut. cz


At the Czech Technical University in Prague, a course in Photovoltaic Systems, dealing with PV system technology (28 hours of lectures, 28 hours of exercises) forms a part of the master study programme in Electrical Engineering and Information Technology. A course of similar length on Photovoltaic Systems has been included in the master study programme in Intelligent Buildings.

Exercises are a very important part of the course orienting the course in a particular direction. The developed laboratory exercises deal with photovoltaic system applications, and are adapted to the requirements of electrical engineers. This paper provides information about the course structure and laboratory exercises oriented towards photovoltaic system applications.

Keywords: photovoltaic system, solar cells, education

1. Introduction

Photovoltaics is one of the most dynamically growing industries at the present time [1]. Yearly growth rates in the period from 2000 to 2007 were on an average more than 40%, and in 2007 PV industrial production grew by almost 60%. In 2007 the production level reached 4.2 GWp. The most of PV systems has been installed in Europe due to introduction of a feed-in tariff for on-grid systems (starting in 2000 in Germany). A level of 6 GWp installed in Europe may be reached by 2010 [2]. The growth of photovoltaics is connected with an increased demand for specialists. Several tens of thousands of new jobs are likely to be created in the field of photovoltaics in the next five years.

At the Faculty of Electrical Engineering of the CTU in Prague a course on Solar Energy Exploitation Systems, mostly oriented in the field of photovoltaics, was introduced in 1995 as an optional course. The course was developed to give undergraduate students information about the full set of important problems connected with photovoltaics from photovoltaic effect, cell construction and technology to applications, including operating conditions and economical and ecological problems. Details about the course were published in [3]. Foreign students from the EU can attend the English version of this subject, that was introduces firstly in the year 2002/2003. Since the school year 2006/7, a course in Photovoltaic Systems, dealing

with PV system technology (28 hours of lectures, 28 hours of exercises) forms part of the master study programme in Electrical Engineering and Information Technology.

Input or output definition?

The selection of the input or the output method depends on the application of the data. Eurostat makes energy balances and therefore the energy input of a conversion process is seen as the energy production. This is in line with the method for e. g. biomass or coal. The output is useful if you want to know the amount of useful heat that is actually used. The final energy as it is used in the renewable energy directive [1] can be input or output. If a solar water heater is placed in a private home the final energy is the energy delivered to the house, which means the energy input to the solar water heater (the input method). If a large solar water heater delivers heat to a network, the final energy is the solar heat delivered to the end-user. In that case the final energy is the output of the solar system (minus distribution losses).

2. Conclusions and outstanding issues

The main conclusions of this paper are:

• Data on the installed collector area is available for most European countries.

• The quality of the statistics on collector area is reasonable, but a the average life-time for solar systems should be included.

• The energy production of the solar systems is still uncertain. The data from Eurostat shows an difference in production per square meter of collector which is not acceptable.

• A large difference is caused by mixing up the input and the output definition.

• To fit in the Eurostat method the input method should be used.

• For the output method the simple formula is an easy way to calculate the average output. The data vary still a lot between countries.

Outstanding issues

• Define the input method. The proposal is 50% of the solar radiation falling on the collector

(which is the insolation at the optimal angle).

• More monitoring data are needed to come to a reliable coefficient for the average output for the

collector. The data is needed for different applications and collector types.


[1] European Union, (2008), Proposal for a Directive of the European Parliament and of the Council on the Promotion of the Use of Energy from Renewable Sources, Com(2008) 19, 23-1-2008, Brussels.

[2] Eurostat Energy Yearly Statistic 2006, (2008), Eurstat, Luxembourg, http://ec. europa. eu/eurostat

[3] Solar Thermal vision 2030, (2006), European Solar Thermal Technology Platform (ESTTP), www. esttp. org

[4] Strategic solar thermal research agenda, (2008), to be published see www. esttp. org

[5] The ThERRA project, several reports see www. therra. info , EU-contract: EIE/05/129/SI2.420023

[6] ThERRA, Proposal for the definition and calculation principle for renewable heat, (2007)

[7] L. Bosselaar, The role of solar heating in the European heat demand, (2006), Eurosun 2006.

[8] R. Segers, (2007), based on the Eurostat data, private communication.

[9] W. Weiss, I. Bergmann, G. Faninger, (2008), Solar Heat World Wide, markets and the contribution to the energy supply 2006, www. iea-shc. org

[10] Technical note: Converting solar thermal collector area into installed capacity (m2 to kWth), (2004), IEA Solar Heating and Cooling programme, Estif e. a.

[11] R. Segers, (2008), ThERRA Benchmark: Test of a Method for Calculating Renewable Heat, CBS,

Therra, www. therra. info

[12] H. Tretter, (2008) WP4: monitoring report, www. therra. info


Despite the assumption that new product development is an activity developed in research centres and development laboratories, there are common product market users that, unsatisfied with the global market offer, pursue the unique solution that fit their specific needs, readapting, reinventing or presenting completely new solutions and products. Dealing with real market gaps, where no solution has yet been addressed by the industry, these users, users as innovators, can be seen as positioned at the top of the innovation process, identifying and solving future market needs. Users as innovators can also be identified as users that find unsolved problems where companies do not believe it is worthwhile investing. (Hienerth, 2004) Led by the need to fulfil their needs not filled by conventional products available on the market, user innovators do not comply with the traditional pre requisites of economic bases to start innovating. According to Von Hippel (2006) this trend, denominated as democratization of innovations, is the result of two related technical trends: improving design capabilities and increasing ability of individual users to combine and coordinate their innovations.

The Portuguese STO

As it is well known, the EPBD [6] imposes the establishment of minimum requirements for thermal performance of buildings, and, for new buildings with a total useful floor area over 1 000 m2, Member States shall ensure that the technical, environmental and economic feasibility of alternative systems such as decentralised energy supply systems based on renewable energy is considered and is taken into account before construction starts (Art. 5).

The new Portuguese thermal performance building regulations related with the EU Directive 2002/91/CE [6], were published in the Official Portuguese Journal (DR — Diario da Repbblica, http://dre. pt/), on the 4th of April 2006. The official documents are:

• Building Certification National System on Energy and Interior Air Quality (SCE [8]), which transposes, together with both RSECE [9] and RCCTE [7], to the Portuguese legislation the EPBD [6], related with energy performance of buildings, and which defines the requirements of the qualified experts that can manage the certification process;

• Air Conditioning Energy Systems Regulation (RSECE [9]), which defines hygienic and thermal comfort conditions, and imposes rules for the air conditioning systems efficiency, for its maintenance and for keeping the quality of interior air, to achieve a better global energy efficiency of buildings. It imposes as mandatory priority consideration in both new buildings and major renovations, with the exception of fault of technical availability demonstrated by the designer under a mandatory methodology, the usage of flat solar collector systems for hot sanitary water production (Clause 2.a) of RSECE, Article 32);

• The referred Thermal Performance Building Regulation (RCCTE) [7], which improves the already existing regulation, almost duplicating the thermal performance request in the new and renovated buildings and imposing the usage of solar thermal collectors for hot water production if there is favourable conditions for exposure (if the roof or cover runs between SE and SW without significant obstructions) in a base of 1m2 per person (the total can be reduced to 50% if space is necessary for other important usages of the building).

Other important requirements of the Portuguese STO defined within RCCTE [7] are the following:

— For performance calculation of such systems, the product certification according to the European Standards is needed.

— This performance calculation is done using a programme developed by INETI, the SolTerm code.

— The installers of these systems must also be certified installers.

— The solar system must be guaranteed by a six year maintenance contract, covering the whole solar thermal system..

• The implementation calendar and taxes of Building Certification National System on Energy and Interior Air Quality [10, 11], is being managed and supervised by the National Energy Agency, ADENE : it began in July 2007 for some type of new buildings, in July 2008 for all new buildings and in January 2009 is extended to existing buildings in the way of a commercial transaction.

Fiscal incentives are available at the moment in Portugal:

a) The annual income taxation of individual contributors can be reduced by 30% of the acquisition value of new equipments for renewable energy production, with a limit of €777 [13];

b) The annual income taxation of collective contributors can be reduced by the value invested in renewable energy equipment at the annual rate of 25% of the overall purchase [14].

c) The VAT incident on renewable energy equipment has the intermediate value of 12 % [15].

An incentive scheme is also available:

a) On SME Qualification and Internationalization Regulation [16], which permits to be eligible the cost of acquisition of the equipment used for both energy efficiency and renewable energy production, and their costs with technical assistance, audits and tests. The energy efficiency and renewable energy production is one of 13 components. The maximum incentive for an individual project (with all their components) is € 250,000.

b) In the Azores Islands there is a Regional Incentive Programme. It is a direct incentive to the acquisition of renewable energy systems up to 25% of the system cost and a maximum of 1000 €. For companies, the maximum value of the incentive is 250000€, also up to 25% of system cost

[17] .

c) Also in Madeira Island there was a Regional Incentive Programme [18] for solar thermal systems for hot water production for dwellings, between years 2002 and 2006. This has now stopped. The collector area installed with this incentive was 3200 m2. It was an incentive up to 1000€ per apartment or 10000€ per building of apartments and up to 70% of the total investment. The incentive was calculated as a function of the energy delivered by the system.

Evaluation of the identified heat and power plants

Open-circuit district heating nets exist only in Russia and in Central Asia. Other CIS or former USSR countries either had only closed-circuit systems (Belarus, Ukraine, Azerbaijan etc) or reconstructed open-circuit systems to closed-circuit ones (Baltic countries).

In Russia and in Central Asia 197 heat and power plants were identified and 163 of them were evaluated so far.

Roughly half of the identified heat and power plants have a closed-circuit system and were, thus, not further considered (cf. Figure 3). 38 of the open — and mix-systems are in operation in summer (cf. Figure 4) and are, therefore, in principle appropriate for solar water preheating. Since no information about the operation mode had been

Fig. 4. Number of identified heat and power plants with open (left) and mix (right) — circuit systems by

operation conditions

In this investigation only large heat and power plants with a possible potential for several thousand square meters of uncovered collector were identified and evaluated. Beside these, various small heat plants exist (without power generation). Some of them have cold water flow rates of 50..100 m3/h, which corresponds about 500 and 1000 m2 of collector. For example, the 6 largest heat plants out of 58 operating in Bishkek have a total potential of approx. 3000 m2 of uncovered collector.

Furthermore, large closed-circle district heating nets could benefit from solar preheating due to their water losses. E. g. the closed-circle in Moscow runs approximately 3 million m3 of water. Hourly water losses of 0.1 % of the net capacity correspond to 3000 m3/h in required feeding water, possibly offering an opportunity for solar preheating.

Estimation of annual heat gains is based on the local climate data as well as on the thermal performance of the uncovered collectors. For Bishkek, three sources of meteorological data are available [3]: the program “Meteonorm”, a local weather station “Frunze”, and measurements since 2004 on a pilot solar thermal system in Bishkek [2]. A commercial water preheating system will be working in the frost-free period, in Bishkek from May to September (5 months). Based on

simulation calculations with the program TRNSYS[3] with conservative climate data energy, solar heat gains of about 1000 kWh/m2a can be expected. The technical and economical potential for the heat and power plant TEZ in Bishkek is approx. 32 MWth (45000 m2 of uncovered collectors), which is more than two times larger than the currently largest solar thermal heat plant in the


A promising option is thereby the recognition of the solar thermal plant as a so-called CDM project in the framework of the Kyoto protocol, which can lead to additional financial gains by the generation and selling of emission certificates. An average emission factor for TEZ Bishkek equals 0.282 t CO2/MWhth when calculated with the specific emission factors of the Intergovernmental Panel on Climate Change (IPCC) and fuel mix of the TEZ Bishkek. This corresponds to an annual emission reduction of 0.31 t CO2 per m2 collector area[5]. An economic calculation of an uncovered collector located in Bishkek was carried out with following assumptions:

• investment (system costs)[6] = 44 € per m2 of uncovered collectors

• solar energy gains = 1 MWh/m2a

• interest rate = 13 %/a

• maintenance = 1 % of system costs

• certificate price (CER) = 6 €/t CO2

• system size = 45000 m2 (corresponds to 2 million € investment)

• operation time =14 a

• fossil price increase rate = 2 %/a

For fuel prices in 2007 (e. g. gas 0.98 ct/kWh) a solar heat price of 0.5 ct/kWh and a payback period of 9 years are calculated. Thus, the heat price for solar thermal heat generation lies significantly below the price for fossil fuels. Without recognition as a CDM project a solar heat price of 0.7 ct/kWh and a payback period of 12 years are expected. If the uncovered collector loop and the district heating net must be separated with a heat exchanger, the solar heat price will rise by another 0.1 ct/kWh.

Furthermore, an economic study[7] for different locations in the CIS was carried out (cf. Figure 6). Energy gains are based on simulation calculations using climate data of the program Meteonorm 5.1. Here, the simulation period is Mai to September instead of the frost-free period to have better comparability between the different sites. The water inlet temperature was set to 12°C for all locations. Some locations, however, were also simulated with the water inlet temperature of 15 and 20°C. The specific flow rate of uncovered collectors in the simulations is 100 l/m2h.


Fig. 6. Solar and conventional heat costs for different locations in the CIS. (15) and (20) represents the water inlet temperature of 15°C and 20°C respectively. Otherwise an inlet temperature of 12°C was assumed.

2. Conclusions

Uncovered collectors can be effectively applied to preheat water for open-circuit district heating nets in cities of the Commonwealth of Independent States. In Russia and in Central Asia in total 197 heat and power plants were identified and 163 of them were evaluated. 38 heat and power plants seem to be technically suitable for solar preheating. Solar heat costs of less than 0.01 €/kWhth can be expected for many sites of the CIS. Large solar heating systems can be recognized as a CDM project to receive additional financial gains.


The authors would like to express their gratitude to the Volkswagen Foundation, Germany and Rudolf and Ursula Lieberum Foundation, Germany for the financial support, as well as to the Power Plants Inc., Kyrgyzstan and to the Almaty Power Consolidated, Kazakhstan for the opportunity to visit their heat and power plants.


[1] K. Vajen, M. Kramer, R. Orths, E. K. Boronbaev (1999): Solar Absorber System for Preheating Feeding Water for District Heating Nets, Proc. ISES Solar World Congress 1999

[2] E. Frank, K. Vajen, A. Obozov, V. Borodin (2006): Preheating for a District Heating Net with a Multicomponent Solar Thermal System, Proc. EuroSun 2006, Glasgow

[3] R. Botpaev, A. Obozov, C. Budig, J. Orozaliev, K. Vajen (2008), Comparison of meteorological data from different sources for Bishkek, Kyrgyzstan, Proceedings EuroSun, Lisbon

[4] E. Frank (2007): Modellierung und Auslegungsoptimierung unabgedeckter Solarkollektoren fur die Vorerwarmung offener Fernwarmenetze, Dissertation, Universitat Kassel

Brazilian Solar Water Heating Systems Evaluation

E. M. D. Pereira[16]*, A. S. de Andrade1, E. M. Duarte1, L. P. Carvalho1, C. V. T. Cabral1, L.
E. M. de Vasconcellos[17]*, E. Salvador2, G. C. dos Santos2, J. T. V. Pereira[18]*, J. T. Fantinelli3,

J. T. Pallottino[19]* and N. C. Guimaraes4

1GREEN — Grupo de Estudos em Energia — PUC-MG, Belo Horizonte, Brasil
2Eletrobras — Centrais Eletricas Brasileiras — Departamento de Desenvolvimento de Eficiencia Energetica
3NIPE — Universidade Estadual de Campinas, Brasil
4CEFEN — Universidade Estadual do Rio de Janeiro, Brasil
*E. M. Pereira, green@pucminas. br
*L. E. M. de Vasconcellos, menandro@eletrobras. com


ELETROBRAS1 and GREEN2/PUC-MG3 are developing a project integrating actions with PROCEL4, to evaluate what is the real situation of the solar water heating systems in Brazil in the residential, service and industrial sectors. Therefore, 7 Brazilian cities were selected to be studied, then information will be collected and statistically treated leading to later field research. At that stage, the collected information are the real design conditions, installation, operation and life cycle of the systems and users’ satisfaction level. Technical questionnaires were developed to summarize all the required information, such as a website, designed to organize and manage the collected data, and a Matlab application that perform the dimensioning and F-chart systems evaluation. Quality indicators are being created through a full system monitoring, with thermographic analysis and evaluation of shading influence at the system’s efficiency, using the Ecotect software. Until now, more than 274 installations were visited of 800 intended to be studied. This article presents some results observed at 3 cities: Belo Horizonte, Campinas and Rio de Janeiro. This project, nationwide, is unprecedented and will get a list of recommendations geared to formulate a development plan for the sector, which could be used as a guideline for government policies.

Key words: Solar water heating, quality indicators for solar water heating systems, products quality, shading analysis.


In 1997, Brazil had created a quality certification program for solar collectors and thermal storage tanks, coordinated by the National Metrology Standardization and Industrial Quality Institute (INMETRO) and ELETROBRAS/PROCEL, counting on the support of Energy Studies Group GREEN/PUC-MG and the Technology Research Institute of Sao Paulo/IPT. Currently,

85 active companies have joined this program, testing in this period 316 models of solar collectors and 281 of thermal storage tanks, presenting nowadays 22% of assays demand annual growth. Solar collectors total area installed in the country is 3,6 millions of square meters, expressing an insertion factor of only 19,2 m2/1000 inhabitants.

In order to create government policies to incentive the usage of solar heating, it is needed to evaluate the real impact of this technology into the national energy matrix with Demand

Management actions, through an estimation of final energy savings and the periods of higher energy demand peak displacement. These are important factors in a country where electric heaters devices participate at about 73% of households’ hot water production for sanitary usage. In the South and Southeast regions, this number reaches 98,6% and 91,1%, respectively [1].

However, the energy production of a solar system depends not only on the component’s quality and thermal performance, but also on their correct insertion in building, appropriated project’s design and quality, besides correct installation and maintenance executions. Therefore, an evaluation of in situ solar water heating systems program has been created in October 2006 in Brazil. The main goal of the finished research, which belongs to this actions program PROCEL integrated, was to characterize and evaluate solar water heating systems in 3 Brazilian cities: Belo Horizonte, Campinas and Rio de Janeiro. These 3 Southeast cities were chosen, among others, because they represent the major penetration of solar water heating in small, medium and large size systems applications in the residential sector, with inherent particularities of usage in different economic groups of population. In Rio de Janeiro, the low income households studied in this project were contemplated with solar water heating, whose all project stages, acquisition and installation were responsibility of the local energy distribution company — LIGHT RIO.

The high income households’ studies were performed at Campinas and Belo Horizonte, in the last of which buildings with central solar water heating were studied.

This project aims the definition of incentive plans to the users and suppliers of solar water heating, training programs to the production and installation companies and designers, the creation of quality marks, besides a statistic filtering about the current overview of this type of system in Brazil.

Energy Institute for Girl

This was the paramount task in the project. Other activities described above were in away auxiliary to this activity. The reasons why women are left out of renewable energy and development projects include lack of culture and history. Lack of women in energy planning and in the engineering field in developing countries such as Mozambique find their root in the cultural barriers of those traditional societies. Unless purposefully engaged, rural women and girls will continue to be lost or alienated customers of energy and other products of science and engineering necessary for the development of their society. Girls’ education and women’s literacy are central to poverty alleviation, sustainable social and economic development, and nation building.

To ensure that women are part of future energy planning and engineering workforce in Mozambique, a program for generating the interest of young women and girls in SMET must be instituted in order to break the cultural barriers which have held them back from participating.

The REEMWaG project pursued this goal by holding an institute for girls in which hands on training were used to demonstrate the power of science in solving real life problems familiar to them. Secondary school girls were selected for the institute each year. Participants were encouraged and supported to pursue SMET education at the college level. In addition to involving the students in the outreach project (example, In the installation of a PV lighting system at the community center), they worked with PV kits to explore the concepts of energy transformation and electrical circuits, with resultant interest in the sciences and engineering.

EMU faculty and local secondary school teachers spearhead the energy institute.

Another means of reaching as many rural girls as possible was through the traveling renewable energy demonstration laboratory. This lab visited schools through out the country and engaged girls and some boys, and their teachers in renewable energy short courses and experiments.

Programme contents

1.1. Courses

ESES is currently a one-year master programme consisting of seven compulsory courses during aprroximately one and a half semester, and about a half semester of (full time) project work. The courses are:

• Renewable energy technology, 5 ECTS

• Solar electricity, 9 ECTS

• Solar thermal, 9 ECTS

• Solar thermal design, 4 ECTS

• Solar energy management, 3 ECTS

• PV/Hybrid system design, 6 ECTS

• Passive solar energy technology, 6 ECTS

• Thesis project, 18 ECTS

Two-three courses are run in parallel. ESES uses predominantly internationally well-known textbooks; presently Boyle (2) Duffie-Beckman (3), Garg-Kandpal (4), and Markvart (5). The main subjects in the courses are introduction to renewable energy sources technologies, solar thermal collectors, photovoltaic modules, and system technology for these techniques as well as hybrid systems. However, since one of the aims with the ESES education is to give a broad overview of solar technologies, subjects like solar architecture (energy performance as well as daylighting), solar economy and solar energy for tropical climates (e. g. desalination, solar cooking, drying and cooling) are treated. There are a number of practical exercises in the courses as well as study visits and computer simulations. Some exercises can be done using our solar simulator, and some of them require good solar conditions, which is why they are conducted towards the start of the academic year, before the long winter sets in.

The programme prepares students for positions in solar businesses or industries and for further studies such as a PhD. The curriculum was presented in some detail at ISREE-8 (6) and is available (along with other information) at the ESES home page www. eses. org.