Marco Calderoni, Riccardo Battisti

Ambiente Italia srl

marco. calderoni@ambienteitalia. it — riccardo. battisti@ambienteitalia. it

Abstract

On January, 23rd 2008, the European Commission delivered the first draft of the Directive, where renewable heating was recognised to play a key role in the sustainable and secure energy supply in the EU.

In this scenario, the EU funded “ProSTO” project (“Best practice implementation of solar thermal obligations”), developed within the Intelligent Energy Europe programme, has the ambitious but challenging goal of acting as a reference in this process, with a special focus on solar thermal in buildings.

The project partnership, which includes Germany, Italy, Portugal, Spain and Romania, comprises research institutes and Local Authorities, which are the main stakeholders, having the task of developing optimised “Solar Thermal Obligations” (STOs). STOs are legal provisions obligating owners of buildings to install a solar thermal system on new/renovated buildings.

First of all, ProSTO will perform a base line assessment, in order to sum up the existing experiences on STOs, together with the needs of the participating local authorities.

A STO developer toolbox will be created for both the implementation by the local authorities and the dissemination at European level.

The core activity of the project will be carried out by 20 local governments of the Region of Lazio (IT), the Cities of Lisbon (PT), Murcia (SP), Stuttgart (DE) and Giurgiu (RO). They will create show cases of best practice implementations of STOs.

1.1. Elaborating lab equipment at UNESCO Chair

The mission of the UNESCO Chair “Renewable energy and electrification of agriculture” is to help people to use renewable energy and environmental building technologies through education. The UNESCO Chair teaches students (who visits VIESH for practical work from universities),

postgraduate students, teachers to understand fundamentals and basic principles of solar engineering, GIS, how to design, install and maintain solar energy systems, and how to design and build efficient, sustainable homes. The UNESCO Chair offers training and retraining to different level specialists of adjacent specializations from around the world.

A number of lab kits were developed at the UNESCO Chair: for studying: parameters and characteristics of solar cells (Fig. 1), ray tracing in models of different concentrators (Fig. 2), operational principle and characteristics of solar module with demonstration load (Fig. 3), characteristics of model solar hydrogen-storage system with reversible fuel cell (Fig. 4), simulating of Sun’s path on the sky and shading of solar systems on models [1] (Fig. 5), characteristics of solar air thermal collector with different absorbing elements and glazing (Fig. 6, left), which includes PV/T receiver (Fig. 6, right).

The systematic development of lab equipment for teaching solar energy and scientific research skills has started at the Chair from 2004 [2, 3]. One of the main tasks of the Chair is integrating educational and research activity of students during the practical work with lab equipment and preparing a research project. VIESH has quite busy test field at the roof on a building which is very suitable for research and teaching activity. Unfortunately sometimes bad or just not sunny weather does allow carrying out proper experiments outdoors in framework of students’ time schedule.

To avoid the dependence on weather described lab equipment was created during last several years. Lab equipment demonstrates principles behind solar energy technologies and is very suitable for using at universities, colleges, technical schools, and secondary schools. The equipment is useful for understanding solar energy, non-traditional and renewable energy, and also some aspects of physics, solid state physics and semiconductors, applied optics.

Fig..6. Lab set for study of solar thermal collector (left), PV/T receiving element of hybrid collector module (right)

Also a special satellite receiver and software was elaborated for demonstrating how GIS systems can be used for solar engineering projects and for study at sciences’ lessons. Lab equipment «Receiving and processing of satellite images of the Earth in real time operation mode» is a new stage of using modern technology. Complex consists of satellite antenna, receiver of satellite signal, software of processing aerospace image of the Earth (Fig.7). Software of the receiving complex «Kosmos — M2» is able to determine the temperature of underlying surface at any point of the image obtained; to measure distance from one point to another with regards the Earth’s geometry; to determine surface area; selection of map layer and so on, to have real time images within interval 2-4 hours. With help of this complex it is possible to study climatic aspects of solar energy.

Fig.7. Satellite receiver of space images of the Earth Satellite with antenna at the VIESH roof

More than 200 students and pupils during the last three years visit our lab for excursion and for practical works and have understood the main principles of solar energy conversion (Fig.8).

At the same time, the total sample’s definition requires surveys and confirmation of the existent number of solar water heating systems. Therefore, a field research has taken place at the 3 cities, where specific questionnaires were used along with fabric and installation companies, commercial stores and customers. The statistic analysis is discussed later.

“Questionnaire A” was developed to raise the technical information, such as collector area sizing estimation, storage tank volume, collectors’ array and insertion in field, general conditions of operation and installation, and equipment maintenance and life cycle. Questions related to sociological and behavioral topics about the use of solar water heating generated “Questionnaire B”. With the creation of a website, dedicated to this project, it was possible to provide secrecy and appropriate ways to transfer and store the collected information.

To develop these questionnaires, important factors — as appropriate language and interest for all the social and economic classes — were included. The inquiry blocks used are illustrated in Figure 2.

The maintenance of this inquiry method in all questionnaires allows the comparative evaluation of the main problems detected. Through this strategy, economic, social, cultural, climatic and technological factors associated to solar water heating had become clearer and easier to understand.

One of the college buildings of the Technical Colleges at Butzbach is a low energy building, demon­strating various building construction technologies in order to reduce the thermal loads of the building. However, demand for active cooling and air-conditioning arises from high internal loads, caused through occupation and computer training courses. The building is used throughout the summer. At present, air-conditioning of the 335 m2 seminar area is performed with two supply/return air systems with heat recovery, providing the required hygienic air change rate. The supply air is moderately pre­cooled by means of ground heat exchangers. The additional solar cooling system, which is currently in the planning phase, will consist of 60 m2 vacuum tube collectors, providing driving heat for two ab­sorption chillers of 10 kW chilling capacity each (type: suninverse of the company Sonnenklima, Berlin). In this application, the collector fluid again is pure water, the collectors are supplied by Para- digma. A heat exchanger for pressure decoupling in the hot water circuit is not foreseen. In periods of high demand for air-conditioning and cooling, the concept allows for a separate operation of the chil­lers: while one operates at low chilled water temperatures for supply air cooling and dehumidification, the second chiller operates the chilled ceilings in the seminar rooms at higher chilled water tempera­tures. For this reason, 130 m2 of chilled ceilings will be installed.

The whole system will be operated in a solar autonomous cooling mode, i. e., without additional driving heat for the chiller operation from the condensing boiler of the college building. The monito­ring of the system is done by ZfS Hilden. The installation of the system is foreseen in late summer 2008. Figure 8 presents a view at the low energy building, and figure 9 shows a sketch of the solar air­conditioning system.

Supply air (2 x 1250 m3/h)

Collector Buffer vacuum tube 2 m3 60 m2

Chilled ceilings (130 m3)

Heat rejection (wet, open)

Figure 9 Simplified scheme of the solar air-conditioning system at the low-energy college building at Butzbach.
The configuration allows to operate the generators of the chillers in series: while the first one produces chilled
water for supply air dehumidification at low chilled water temperatures, the second one is thermally driven with
the return heat from the first one and produces chilled water at temperatures > 15°C for the chilled ceilings.
Consequently, the temperature difference between supply/return fluid in the solar circuit is increased.

References

[1] Hans-Martin Henning: Solar cooling and air-conditioning — thermodynamic analysis and overview about technical solutions. Proceedings of the EuroSun2006, June 27-30, 2006, Glasgow, Scotland

[2] Hans-Martin Henning, Edo Wiemken: Solar Cooling. Proceedings of the ISES Solar World Congress, September 18-21, 2007, Bejing, China

[3] Hans-Martin Henning (Editor): Solar-Assisted Air-Conditioning of Buildings — A Handbook for Planners. Published 2004 in the frame of Task 25 of the Heating & Cooling Programmes of the IEA. Revised edition 2007. Springer Wien New York, ISBN 978-3-211-73095-9

[4] Edo Wiemken: Solar cooling and air-conditioning — Programmes and projects for demonstration and technology transfer. Proceedings of the 9th International Symposium Gleisdorf Solar, September 3-5, 2008, Gleisdorf, Austria

[5] Laura Siso Miroo, Tim Selke, Anita Preisler: Market Opportunities for Solar Cooling. Results from the ROCOCO Project. Proceedings of the International Seminar Solar Air-Conditioning — Experiences and Practical Applications. June 11th, 2008, Munich, Germany

[6] Uli Jakob: Overview on Small Capacity Systems. Proceedings of the International Seminar Solar Air­Conditioning — Experiences and Practical Applications. June 11th, 2008, Munich, Germany

[7] SOLARTHERMIE 2000plus. Forderkonzept des Ministeriums fur Umwelt, Naturschutz und Reaktorsicherheit im Rahmen des Energieforschungsprogramms des Bundes. Carried out by the Project Management Organisation Julich (PtJ). www. solarthermie2000plus. de

Solar One has attended about 50 public events, such as agricultural shows over the last two years. Many visitors are interested in installing renewable energy equipment and we are able to help them, explaining how it works, the potential for energy and money savings, contacts for installation companies and sources of grants and funding.

5. Financing

A fee is usually requested for schools visits. We charge EU 100 for a half day(1 school), EU 150 for a full day(2 schools) and EU 500 for a full week (10schools). Most education authorities and schools are quite happy to meet these charges. Over a year, our normal income from these charges is about EU 4,000 and our normal expenses (maintenance, fuel, road tax, etc) is about EU2,000. Therefore the whole venture is now self financing and we have even been able to pay back some of our initial funders. It should be noted, however, that the driver/ lecturer provides his services as an unpaid volunteer. If wages had to be paid, that would cost an additional EU6,000.

6. Conclusion.

The Solar One project has been a great success. It has taken renewable energy, especially solar, into the community and is now financially self sustaining. The Scottish Solar Energy Group is happy to share our experiences with any other organisation which wishes to do something similar.

Rain water harvesting­collecting water from roof into 1500 gallon plastic cistern.

Fig 4: Schematic diagram of rain water harvesting technology

6.1 Gutter details and collection of rain water

This plan is showing the details of rain water collection. Gutter details and rain rater collection method is also shown. Two particular filters and a ultra-violet light are used to sterilize water estimating 10 gallons of water per minute.

Rain water harvesting is broadly classified into two categories. They are surface runoff and roof-top harvesting. In both the cases, it is mandatory, prior to rainy season, to clean and maintain the segments free from all other contaminations that are added earlier. This harvesting is very much essential to cater the demands of water for drinking, domestic purposes and aimed to generate power and gas. In turn over a long range helps as follows:

• Conservation of water

• Reduction of soil erosion

• Arresting of ground water decline

• Beneficiates quality of water

A survey was done in order to identify bioclimatic design and passive solar strategies for cooling and correspondent benefices. Actually exists in Mexico programs and projects for construction of social

houses in large scale and based on that survey were selected some of the approaches used for the different types of climate, air conditioning solar systems, solar hot water and water reuse. In Ciudad Juarez were used as passive solar strategies the ground cooling ventilation and shading devices. In Mexico D. C. particular attention was given to the house implementation and windows orientation in order to minimize the solar exposure and at same time the use of effective shading devices. For hot dry climates (Santa Isabel, Chih.) is recommended the use of massive materials in order to increase the thermal inertia and established of interior microclimates. However, in Mexicali, the strategy consists on the application of thermal insulation and the electrical energy production [1].

A study on the CO2 emissions was done for the period 2001-2006 and one prevision for the period comprise 2007-2012. The construction of 6 millions of social houses until 2012, approximately 23% of the number actually existent, will contribute for an increase on 16,770 GWh of the electrical energy consumption. Nowadays is been elaborated the guidelines for the social houses in Mexico and the first text for sustainable houses Certification [2].

E. Villa1*, C. Winkler2, M. Calderoni3, V. Drosou4, E. Wiemken5, M. J. Carvalho6,

Q. Cavalera7, O. Ayadi8, J. R. Lopez9, D. Mugnier10, S. Medved11, T. van Steenberghe12,

M. Proville13

1 target, GmbH, Walderseestrasse 7, 30163 Hannover, Tel 0511 909688-30, Fax 0511 909688-40,

villa@targetgmbh. de
2AEE — INTEC, Austria
3Ambiente Italia, Italy
4CRES, Greece
5Fraunhofer-ISE, Germany
6INETI, Portugal
7Provincia di Lecce, Italy
8Politecnico di Milano, Italy
9EVE, Spain
10TECSOL, France
11Uni. Ljubljana, Slovenia
12REHVA, The Netherlands
13AIGUASOL, Spain

* Corresponding Author, villa@targetgmbh. de

Abstract

In the framework of the European Union’s Intelligent Energy — Europe Programme, the SOLAIR project aims at the acceleration of the growth of small (up to 20 kW) and medium sized (20 kW — 105 kW) solar air conditioning (SAC) applications. In this scope, specific actions are being elaborated in order to promote, assist and influence the process of decision­making for the implementation of SAC systems and consequently to increase the confidence and the knowledge on the respective technology, mainly in the residential and commercial sector. The present work will describe the main results developed until half time of the project, which was initiated in January 2007 and will be concluded in December 2009.

The major results can be seen in the project web-page www. solair-project. eu.

Keywords: solar thermal systems, air-conditioning systems, SAC promotion, training

1. Introduction

In the framework of the European Union’s Intelligent Energy — Europe Programme, the SOLAIR project aims at the acceleration of the growth of small (up to 20 kW) and medium sized (20 kW — 105 kW) solar air conditioning (SAC) applications. In this scope, specific actions have been elaborated in order to promote, assist and influence the process of decision-making for the

implementation of SAC systems and consequently to increase the confidence and the knowledge on the respective technology, mainly in the residential and commercial sector.

Thirteen partners from Austria, France, Germany, Greece, Italy, Portugal, Slovenia, Spain and The Netherlands, including complementary partners to cover the full range of necessary skills and technical excellence, participate in the project.

The main targets of SOLAIR are:

• Promote the market implementation of small and medium-sized solar air-conditioning appliances, focusing on the residential and commercial sector, combining domestic hot water supply and space heating with air-conditioning

• Resolve major market obstacles: limited awareness on know-how as well as available instruments and the lack of information

• Create a set of instruments (including comprehensive training material) to assist the market growth of this technology

• Elaborate a set of measures targeting at the relevant key market actors

• Disseminate the activities in Europe and on national level

SOLAIR is addressing three relevant groups of market actors, which represent bottlenecks for a wider market diffusion of solar air-conditioning technologies:

Providers: engineers, plant designer, manufacturers, installers and technicians.

Investors: owners of residential and commercial buildings

Promoters: energy agencies, thematic networks, political decision makers, associations and NGOs

The present work will describe the main results developed until half time of the project, which was initiated in January 2007 and will be concluded in December 2009.

Presently all Work Packages (WP) were initiated. In section 2. the activities of the WP dedicated to “Market review and analysis of small and medium-sized solar air-conditioning” are described.

Section 3. is dedicated to the ongoing activities of the WP dedicated to “Capacity building and training activities”. In Section 4. the first results of WPs dedicated to “Information and awareness campaign towards the key market actors” and “Communication and dissemination” are presented. Section 5 is dedicated to the interaction of the project to other European and International activities and the way that the different activities contribute to the development of the main objectives of SOLAIR. In Section 6., as conclusions to the present work, the present view of the project partners to the main positive and negative aspects to the present development of the SAC systems is described.

Photovoltaics is a broad, interdisciplinary field of study. On the one hand, students need a good knowledge of materials physics and interactions with incident light, optimisation of cell structures, and anti-reflection coatings, in order to understand the physical structure of different types of solar cells. Many technological processes are used in the fabrication of solar cells and photovoltaic modules. Applications of photovoltaics involve a good knowledge of the characteristics, the relations between load and maximum power output, and the influence on cell efficiency of operating conditions, especially cell temperature. Students should have a sound knowledge of power and control electronics. As the output power of photovoltaic systems depends on temporary solar irradiation, some basic knowledge of solar physics and meteorology are very important, along with an understanding of problems of local shading, etc.

Individual aspects of photovoltaics may be studied separately and in isolation. Photovoltaic materials, cell physics, cell and module technology are studied by physicists, chemists and technologists, converters are studied by electrical engineers. Architects, designers and utility engineers take a special interest in PV system applications, but are less interested in problems of materials and technology. However, each of these topics forms parts of a single system, in which the economic aspects of the individual disciplines must be taken into account.

On the other hand, isolated aspects of a general course on renewable energy sources will not provide a sufficient understanding of the range of interconnected problems in this field. The education system must combine the appropriate information and bring out the relationship between scientific knowledge and everyday life. Apart from the universities, many other institutions can contribute to studies of photovoltaics, at various levels. Such an education programme requires teachers with extended

knowledge. Teachers need to be specially educated to deliver courses and classes that will meet the economic and social demands of the development of photovoltaics.

Europe is without any doubt the worldwide technological leader in solar thermal (ST) development. European companies lead mainly in the following sectors:

• Selective coatings for absorbers

• Advanced collector production methods (e. g. laser welding)

• Advanced flat-plate collector technology

• High-quality vacuum tube collectors

• Process heat collectors

• Stratified hot water storage tanks

• Electronic controllers

• System technology (e. g. solar combined systems for domestic hot water and space heating, with a burner directly integrated into the storage unit)

• Large-scale ST systems combined with seasonal heat storage

• Advanced applications (cooling, combined systems and industrial applications)

Clearly, Europe is currently leading in nearly all sectors of ST technology, which explains why the manufacturing capacity in Europe is growing enormously, notably in relatively high-wage countries, such as Austria, Germany, Denmark and the UK.

Moreover, some European countries, including Sweden, Denmark, Germany and Austria are leaders in low-energy building technology, which is a prerequisite for a high ratio of solar thermal energy in heating systems. In this area, strong cooperation with other technology platforms, such as ECTP and SusChem, is necessary.

The significant growth seen in the European market over the last decade has helped to consolidate this technological advancement. However, the current market size in Europe (around 2 GWth new installed capacity per year) is still small, compared with the current Chinese market (12.6 GWth per year) and the expected future global ST market, which could reach 100-200 GWth within a decade.

The technological perspective for the potential of solar thermal use in Europe is enormous. On the basis of comparative data on the current market development in Europe and globally, it is shown that in the short term (until 2020 at least), and with existing technologies, the solar thermal market can grow immensely without reaching the point of market saturation.

Figure 2 shows the growth in solar thermal energy use according to different scenarios. The lower graph shows the development in the case of business as usual, the middle graph shows the case of advanced market deployment, whereas the upper graph indicates the development needed to supply our energy sustainably.

Figure 3: Solar thermal contribution to the EU heat demand sector.

Figure 3 shows the contribution of solar thermal energy to the EU heat demand sector. The long-term potential of solar thermal energy is to meet around 50% of EU heat demands. In order to achieve this goal, an installed capacity of 2576 GWth or 8m2 per inhabitant would be necessary. This potential can be achieved by 2050 provided an appropriate mix of R&D efforts and market deployment measures are taken into account.

This 50% goal is only achievable, if at the same time the heat demand of our building stock is reduced by 40% (figure 3). Therefore efficient use of energy in combination with effective integration of solar energy is the important goal. For this we need new technologies, new materials and system approaches.