Category Archives: EuroSun2008-9

Data Acquisition

For the first time it has been necessary to monitor solar thermal performance on a daily basis in order to provide proper billing and performance review. Previously metering was simply not completed and the owner had no idea whether the solar system was performing or not. This undoubtedly led to client frustration when systems did not appear to be impacting utility bills as anticipated.

No solar thermal-specific data monitoring or metering equipment existed at any scale in North America prior to the build out of Mondial’s projects. Mondial therefore sourced its metering capabilities from Europe. First of all Mondial focused on small scale district hot water heating metering calculators as the key data acquisition component: flows and temperatures are consistent with those found in typical solar thermal installations. Secondly the market for flow meters available in North America is focussed on industry use and their typical high flow rates for a given pipe diameter, whereas low flow measurement is crucial in capturing all the flow and therefore available revenue in solar thermal. Imported flow meters have permitted capturing a single fixture unit (e. g. a shower) in a 50mm domestic hot water pipe, rather than having the meter cut out due to low flow conditions.

Another key aspect for Mondial has been the ability to demonstrate to our clients their system’s energy production in real time. Mondial worked with a leading renewable energy metering company to modify their existing solar electric systems to work with thermal meters. The result has been the first real time monitoring of solar thermal systems in North America.

This has permitted client-friendly readings of carbon offsets and easily understood energy generation details.

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Fig. 3 — Data monitoring in real time

Crucially for Mondial this data acquisition has permitted ongoing refinement of system design; minute by minute flow data has provided accurate usage profiles for different building types while domestic cold water temperatures have allowed model input data to properly reflect system behaviour over time.

Additionally Mondial has been able to take this data and prove coincidence between hot water usage in multi-residential buildings and peak electrical system load days. While intuitive, we have been able to demonstrate that peak electricity consumption coincides with peak solar activity at the exact hours when the system is under strain, and that during these key peak hours Mondial’s storage tanks and hot water delivery temperature grade ensure that electric hot water heaters are not in operation. This means that investment in solar thermal for a building with electric hot water heating can directly offset requirements to invest in new power plant production and constitutes a fuel switch strategy away from electricity, without the need to move to natural gas or other carbon- based sources.

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Fig. 4 — Review of coincidence of solar thermal offsetting electric hot water production on peak electricity

days in Ontario (2007, Ontario Power Authority)

Finally remote metering allows Mondial to view energy generation monthly on line and issue invoices without the need to visit sites, eliminating geographic constraints for system installations.

1.3. Commissioning

Analogous to the green building movement currently gaining momentum in North America, solar thermal systems simply do not perform well unless thorough commissioning takes place during the design, construction and operation phases. For Mondial this has meant reviewing our suppliers’ designs during the energy modelling and design stages, and also helping them modify system specifics (collector numbers, storage volumes) based on experience gained from Mondial’s pre­existing data. During build out Mondial now has access to real time performance data permitting peak and transitional collector performance review. This has provided the contractor the ability to optimise flows to ensure resulting energy capture.

From a financial point of view Mondial also needs to understand how its systems perform compared to their predicted energy models, on which investment decisions are made. Ongoing data review results in refined performance models that contribute to better performance certainty, and therefore economic predictability. This is inherent risk mitigation from our funders’ point of view.

1.4. Maintenance

Mondial’s success depends on ongoing system performance. Mondial has therefore had to develop maintenance specifications and negotiate annual maintenance contracts with providers. Again this is an activity that had not been completed at any scale or replication in the solar thermal industry.

1.5. Conclusion

In moving to a Power Purchase Agreement model for the delivery of solar thermal energy, the necessary advancements in metering, data acquisition and commissioning have pushed the solar thermal industry to new heights of service, quality and energy delivery certainty.

Sizing the renewable energy systems

There are several options of renewable energy systems available in the market, in this study were considered the solar thermal (ST) and the photovoltaic (PV) systems. This two system were adopted, since they have shown to be effective in urban environments, special in southern european climates, where sun irradiation is high.

DHW represents a significant share of the overall energy demand, making it a preferential target for renewable energy use. Thus, a solar thermal system is used to supply the DHW. In adition we also considered the use of solar thermal to supply hot water to the washing machines (MHW) and the heating needs of the house. The auxiliary energy of the ST and the cooling (and heating in some scenarios) needs are supplied by a heat pump with an average COP of 2.5.The PV system is sized so that it supplies all the electric needs of the house, including the electricity needs of the heat pump on a net yearly basis.

2.3 Solar thermal system

The solar thermal system is composed by: a reservoir and a set of solar thermal panels with 50° inclination facing south, as discussed, a heat pump provides the auxiliary energy, needed to maintain the water in the reservoir above 43°C. The inclination of the thermal solar panels was optimized using the simulation software EnergyPlus. When the water in the reservoir reaches very high temperatures (80°C) a heat rejection system is used.

Leaflets to installers

It has been edited a leaflet for diffusion of solar cooling, in which era described the different technologies, as well as are given some useful links where to look for extra information.

2. Conclusions

Whit the project Best Result has pretended to develop the RES with different approaches: analysis of the situation by means of surveys sent to different actors on this sector; diffusion labours at two levels: for public in general and on the other hand for technicians and people already involved on this sector. CARTIF, as partner of the project, among other topics have been in charge of the solar cooling topic, falling a structure similar to the one of the whole project.

Its necessary to thanks to all the participants on the project and to the European Union, the effort done for the promotion of the renewable energies as an option for the future that allows having a cleaner environment and less contaminant processes for energy production.

References

[1] BEST RESULT (2008) Page Web: http://www. bestresult-iee. com

[2] SACE: Solar Air Conditioning in Europe. Final Report, EU Project NNE5-2001-25, 2003

[3] TRNSYS 16 Documentation. A transient Simulation Program. Solar Energy Laboratory, University of Wisconsin, Madison, 2006

[4] U. Franzke, Uwe, C. Seifert Solar Assisted Air Conditioning of Buildings, IEA Task 25, Subtask B: Design Tools and Simulation Programmes, Documentation for the SolAC Programme, Version 1.2, 2004

[5] H. M.Henning, J. Albers, Decision Scheme for the selection of the appropriate technology using solar thermal air-conditioning. Guideline document, International Energy Agency (IEA), 2004.

Support and financing

Finance was raised from the public and private sectors, including SSEG, the Scottish government and several renewable energy companies. Some companies donated equipment rather than cash. In total, a sum equivalent to approx EU20,000 was raised. This allowed a van to be purchased and equipment bought. We decided to call the van “Solar One”, because it is the first of its kind in Scotland.

2. Planning and conception

It was decided that the van should be propelled as far as possible by renewable energy. Research showed that electric propulsion was not feasible because of lack of range and lack of facilities for recharging. The best alternative was bio-diesel and this was the preferred option. Therefore a second-hand diesel van (Ford Transit) was purchased for about EU 10,000. No engine modifications were needed and the van can run on any mix of fuel from 100% bio-diesel to 100% mineral diesel. No problems have been encountered.

Design and Orientation

In the design, built-in, customized environment-friendly, zero electricity refrigerators, and built-in energy efficient lights are among the features that help to bring down energy consumption in the home while ensuring comfort levels

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Fig 1: Design features of Universal Home.

 

The Use of Bioclimatic Design and Strategies in IberoAmerica

S. Camelo and H. Gonsalves

INETI, Department of Renewable Energies, Campus do Lumiar do INETI, 1649-038 Lisbon, Portugal
Corresponding Author, helder. goncalves@,ineti. pt

Abstract

This paper presents an overall review and synthesis of building construction studies and activities in the field of Bioclimatic Buildings, carried by an Iberoamerican network supported by the CYTED Program. This network, include Argentina, Brazil, Chile, Ecuador, El Salvador, Mexico, Peru, Portugal, Paraguay and Spain in a total of 14 Institutions. The main goal of this network is to improve the use of renewable in social housing programs as also to improve the design and implement bioclimatic strategies in this type of building in those countries. This project aims also to help to came closer the main actors in the field in order to set up local or national programs in social housing, putting together these actors at national level, developing ideas, projects, legislation, conferences, seminars or networks. During these three years project, an important review of building construction has been set up, discussed and presented in several main seminars (El Salvador, Mexico and two in Argentina). In this paper a national review of projects and building constructions are presented and discussed in most of these countries as also the main ideas and goals for each of the participants.

Keywords: Social buildings, renewable energies, bioclimatic design.

1. Introduction

The Project started in 2005 and was defined a base program with four main tasks: 1) survey and revision of the constructive practices, passive systems and renewable energies use, systematization of the information in order to define, for each country, the sustainable measures to be implemented; 2) thermal performance evaluation of some buildings and systems; 3) development of building guide lines; 4) dissemination actions.

In the first year the participating countries have done a considerable effort in the survey of the case studies and the results were presented in a Seminar, open to all Argentine groups, in October in San Martin de Los Andes. The main results were published in the proceedings “Bioclimatic Buildings in Iberoamerican CountriesWos Edificios Bioclimaticos en los Paises de Ibero America “ [1].

In April 2006, at El Salvador, a Seminar was undertaken on “The use of solar energy in social buildings “Uso de la Energia Solar para Viviendas y Edificios de Interes Social” and in the CYTED meeting was decided that all groups should be familiarized with buildings thermal and energetic simulation methods in order to evaluate the thermal behaviour of the social houses case studies selected. For that purpose was organized in June, at University of Sao Paulo, a Workshop in order to allow to all the network groups evaluate the thermal performance of the implementation of the corrective measures namely at the building external envelope. Three months later, at Buenos Aires, a

CYTED meeting was undertaken in order to discuss the first simulations results and to overcome the difficulties founded by each group.

In 2007 two Seminars of dissemination and technological transfer were done, one in June Mexico D. C. under the titles “Social Buildings in Iberoamerican countries’Yos Edificios de Interes Social en Ibero America” and the other in November at San Luis, in Argentina, “Buildings in the Future, Bioclimatic Strategies and Sustainability’Yos Edificios en el Futuro, Estrategias Bioclimaticas y Sustentabilidade” [2].

This year a Seminar will take place at Lisbon in next October open to all the scientific community and also the final meeting in order to make the balance of the network contribution in each participating country. The network in all countries wherever organized seminars always meant to be open to others groups and to promote and enhance discussions of these subjects.

Population universe selected

The population selected for the transference was the following:

— In the village of Antofagasta de la Sierra: students, parents and teaching staff of the N° 494 Secondary School.

— In the settlement “Los Bajos”: 36 persons with family ties sharing their habitat. They are 6 family groups with different internal structure.

1.2. Transference methodology

■ Firstly, the technicians in charge of the field work were trained to develop their activities in both locations with the purpose of giving them the necessary tools to comply with their duties, taking into account the fact that they receive the users’ comments and thus are able to suggest modifications in order to improve the devices to be transferred.

■ In the village of Antofagasta, data were collected in order to become familiar with the population practices related to the use of wood in the school and family environment so as to generate discussion about the land degradation problems and the possibility of using alternative energy sources. The technology use and maintainance was accomplished in practical ways during training workshops carried out in the school building so that the kitchen staff could work together with the technicians, thus being able to acquire skill in the different procedures.

■ In the village of Antofagasta, diffusion started in the school because the socio-cultural and educational activities of the population are concentrated in this institution. Demonstration workshops were thus conducted with the participation of the school staff during which different meals were cooked. The idea was to train the people in charge of meals preparation and, at the same time, make the students aware of the advantages of solar technology, so that they could later become multiplying diffusion agents.

■ In “Los Bajos” the time to make the technology known was connected with the life objectives of the families and with the production of symbolic representations. The changes generated were monitored so as to help the participants to take ownership of the alternative energy in their daily activities. Simultaneously, quantitative and qualitative

analyses about these daily applications were carried out. The techniques used were: participant observation, case histories, focused interviews, “leam by doing” technique and workshops to develop training related to the use, preservation and cleaning of the solar cooker. In order to obtain a collective overview, the nominal group technique was applied.

■ Later, in the same location, the emphasis was placed on the creation of three micro

enterprises for the elaboration of bakery products, handmade jams, and pickled vegetables using, mainly, the solar technology. These enterprises were proposed taking into account the participants’ previous knowledge so as to change retail sales for sustainable strategies. Monitoring and evaluation indicators were considered to measure the impact of the activities in family lives. The basic strategy for skills and capacities development and knowledge acquisition was the training by means of workshops and working spaces where family members interested in the micro enterprises were given technical support and in situ exercises. The experience was systematized for proper analysis and improvement and for eventual replicability.

The experience in both locations was developed in 18 months.

Project Execution

During the still construction and upon completion of the still, the students’ understanding of the construction process was reinforced through first-hand experience. Math problems were used that required students to interpret project plans and calculate material takeoffs thus strengthening students’ knowledge in one of their weakest subjects. The students’ knowledge of the natural physics in solar distillation was acquired during still construction and seeing the still in operation.

Students’ comprehension of solar distillation was tested at the beginning of still construction and throughout. In the practical labs, time was allotted by the teacher for the construction of the improved solar still with small groups of students. The practical lab monitors helped to manage groups of students performing project construction, increasing project involvement and building capacity.

The solar still and the solar flat-plate collector were not completed during the school year, due to difficulty in obtaining materials, as well as comprehensive senior testing at the end of the year. The improved solar still construction was completed during the summer, with the help of a few motivated students who took the initiative to come back to school to help. Distillation results are still pending.

Testing the project materials in training activities

1.1. Curriculum design

Based on the findings provided by the needs analysis, the in-service teachers’ training course curriculum, as presented in Table 1, was designed.

Table 1. Course Curriculum

Module

Lectures

(hours)

Applications

(hours)

Basics of the energy production

4

Renewable Energy Sources: solar radiation; wind; hydro; biomass; other

6

6

Solar — thermal systems

8

12

Solar PV systems

8

12

Passive solar use

2

4

Systems for Wind Energy conversion

6

8

Small Hydro Systems

4

6

Biomass

6

8

Hybrides: S/T + wind; Solar PV + Wind; S/T+ PV + Wind; Co-generation Systems:

6

6

Energy efficiency and energy saving

4

4

Environmental Management

Air, water, soil: Pollutants, Monitoring Integrated

Environment Management

8

12

(Waste) water treatment

8

12

Waste management, Waste recycling

8

12

Heating pumps and hydrogen production

6

8

Applied English Language

2

10

Novel teaching using ICT

2

10

Final project development

Final project evaluation

The sustainability concept was considered in the curriculum: technical dimension — specific modules related to renewable energy systems; ecological dimension — modules related to environment (pollution/protection, monitoring and management), and also to wastes management; cultural dimension — modules related to novel teaching methods and to the didactics required by the implementation of the subject of renewable energy in the school curriculum, also the applied English language was proposed, considering that the teachers are not native English speakers.

At the same time, the course materials were developed by the partners in the project, according to a general structure of the syllabi agreed in the partnership. Thus, it is considered that the in-service training course has a deep international character, combining the experience in different countries, and different positions in the socio-economic system.

In the Transilvania University and also in the College for Natural Sciences, sets of training kits were developed this representing important output of the SEE EU Tool project. The kits are intended to be used by student-teachers during the in-service training course, but also during the instructional activity.

The installed capacity

The collector area is a useful figure for the solar thermal experts, but it cannot be compared with the installed capacity in other fields. Therefore the IEA Solar Heating and Cooling programme, Estif and other trade associations have adopted a value of 0,7 kw/m2 as average capacity [10]. This conversion factor has been adopted by the IEA statistics department. Eurostat is considering using the same factor for their statistics. The installed collector capacity can now be compared with other technologies [9].

1.2. Monitoring of the solar thermal production

The total thermal production is in general calculated from the installed collector area. Most countries use a simple figure per square meter of collector. The IEA Solar Heating and Cooling programme has a more sophisticated method that includes the simulation of a typical solar system for each country [9]. Eurostat takes over the figures from the statistical offices in the EU-countries. They ask for the collector input as in their definition in the input-method. This is the energy falling on the collector minus the collector losses. Most countries seem to use a figure that is available in their country. In table 1 it can be seen that there is significant difference in the production per

square meter of collector. It varies from 64 to 903 kwh/m2 [8]. This difference cannot be explained by the difference in insolation or quality of the solar collector systems.

Table 1. The average output per square meter collector used in several countries, based on Eurostat data [8]

Country

kwh/m 2

EU-27

437

Belgium

408

Czech Republic

337

Denmark

363

Germany

411

Ireland

406

Greece

391

Spain

898

France

412

Italy

562

Cyprus

658

Hungary

500

Netherlands

352

Austria

352

Portugal

903

Finland

64

Sweden

185

United Kingdom

586

The ThERRA project is proposing a fixed method for calculating the collector production, based on measured data. If no measured data are available a default value can be used.

In the benchmark report of the methodology the difference with the current methods is found [11].