A. Lalayan1* and V. Afyan2

1 SolarEn, LLC, 2/2 Shrjanayin Str., Yerevan 0068, Armenia

2 SolarEn, LLC, 2/2 Shrjanayin Str., Yerevan 0068, Armenia

* arthur lalayan@solaren. com

Abstract

This article discusses the need to meet the challenges in renewable energy development in Armenia through comprehensive education. These challenges require going for changes in perception of the reality related to the stage of technological development and future energy demand taking into account scarcity of the organic fuel and environmental implications of the traditional energy sources. This applies from generation to consumption, and from planning to education in general. Renewable energy education is imperative for Armenia. It should start from schools but also involve and be comprehended by public and statesmen. Introductory classes in schools and both no-degree and degree classes in universities, public awareness and decision-makers training programs will help in understanding and utilizing the country’s indigenous and sustainable energy resources.

Keywords: Renewable energy, Armenia, education

1. Introduction

Both developed and developing countries need in state support to promote renewable energy technologies as sustainable energy solution for tomorrow. In this respect education and public awareness of not only technical aspects but also benefits the renewable energy can offer to general public and to the state is crucial.

The energy sector of Armenia was integrated in unified energy system of the former Soviet Union, during which cheap energy was available to population. Currently, the country is heavily dependent on imported fuel (natural gas and nuclear fuel). To enhance country’s energy security and reduce dependence on foreign supplies Armenia needs to develop its own renewable energy resources.

These challenges require going for changes in perception of the reality related to the stage of technological development and future energy demand taking into account scarcity of the organic fuel and environmental implications of the traditional energy sources. This applies from generation to consumption, and from planning to education in general. A number of programs to promote renewable energy in Armenia were implemented since mid 1990s, and only limited disciplines within the general power engineering programmes incorporate basics knowledge in renewable energy. Education and public awareness projects included small scale publications for general public and workshops or seminars under donor funded projects. An introductory and non­mandatory renewable energy classes are incorporated in very few universities’ curricula. However, this is not enough to get public accept and adopt renewable energy in their lives. Adoption of new technology will require new knowledge, skills and change in mentality. Spreading the word becomes crucial, preaching and teaching — imperative.

At the Central State Archive, documents from public and private archives will be on display in an area of 600 square meters to recount the efforts made by the pioneers of the 19th and 20th centuries in order to achieve with solar energy the same things accomplished with fossil and nuclear fuels, i. e. heating and cooling buildings, illuminating day and night living and working spaces, powering farms, industries and other human activities.

Gaetano Vinaccia (1889-1971), an architect and city-planner, is the author of dozens of little known publications and articles on solar urbanism and architecture. Among them is the 385 page book “Il corso del sole in urbanistica ed edilizia” (“The path of the Sun in urban planning and building construction”), published in 1939 in which Vinaccia reviewed systemic architectural and city-planning aspects of the use of solar energy over the ages, in the conviction that the past has to be placed at the centre of any enterprise headed for the future [8][9].

Giovanni Francia (1911-1980), a mathematician and engineer, thought that solar heat, abundant at low density and temperature, needed to be collected at high temperatures in order to be useful in modern societies to run industries and power plants. He was the first person ever to apply the Fresnel Reflector Technology principle in real systems, linear, in Marseille in 1963, and point focus, in S. Ilario in 1965. He envisioned a modern city powered only with solar energy. In 1970, before the 1973 oil crisis, working with two young architects, Bruna Moresco and Karim Armifeiz, and other collaborators, Francia developed a visionary project for a model energy-independent city, with a population of about 100,000 that would rely on solar energy. He called it "The solar city — Hypothesis for a new urban structure [10][11]."

Francia was one of the first people in modern times, if not the very first, to propose the idea of the solar city so explicitly. It was precisely because of this pioneering intuition of Francia’s that GSES and CONASES decided to organize the 1st Solar Cities exhibition in Genoa, and to honour him with a 20-minute DVD [12]."

In Rome new documents and pictures on the Solar city project preserved in Brescia in the Francia Archive will be on display.

At the venue of the Central State Archive highly visible projects of solar buildings and cities headed for the future, selected either from Italy or from other countries, will be exhibited as well.

6. Conclusion

The "Italian Solar City Travelling Exhibition" is part of the “Italian National Solar Energy History Project” whose purposes are first and foremost cultural. It aims at changing the perception people have about solar energy and at envisioning that it is possible to combine the knowledge of the past, as recommended by Vinaccia, with the introduction of the most advanced solar technologies, as those pioneered by Giovanni Francia, on a large scale in a modern or future city [13].

The special symbolic environments offered by the Museum of Roman Civilization and the State Central Archive, should contribute in addressing the scientific challenges and research directions toward either the past or the future, in order to use the best of both as suggested by Norbert Lechner. The exhibition will show how to rethink our future energy infrastructure and its technological, organisational and cultural implications. How to supply solar-generated electricity, heating and cooling to homes, hospitals, schools, industries and offices, for transportation and other economic activities. It will especially focus on the importance of solar light and heat, as directly available in nature, for day lighting, heating and cooling buildings, that are the greatest consumers of energy in modern cities.

6. Acknowledgements

In writing this paper I had the benefit of accounts from and contacts with many people. I would like to thank in particular, C. F. Giuliani, M. Martelli, R. Merola, G. Nebbia, P. P. Poggio, L. Ungaro, U. Wienke and the heirs of G. Francia, and G. Vinaccia.

References

[1] K. Butti, J. Perlin, Solar Houses and Cities in the Ancient Mediterranean, Sapere 2006; www. gses. it 2008.

[2] C. Silvi, S. Los, The Italian Solar City Travelling Exhibition, Poster Presentation, Proceedings International Solar Cities Congress, Oxford, 2006; www. gses. it 2008.

[3] C. Silvi, Prima edizione a Genova della mostra su storia e futuro dell’energia solare nelle citta (First exhibition in Genoa on the history and future of solar energy in cities), Scienza e Tecnica, December 2006; www. gses. it.

[4] Videoclip, Le citta solari al Festival della Scienza di Genoa (Solar Cities at the Genoa Science Festival), You Tube 2006; www. gses. it/conases/genova. php.

[5] N. Lechner, The Future of Architecture: Sustainable Architecture, Lecture delivered in China in 2007 (private communication).

[6] L. Ungaro, Perche una mostra su mostra sull’energia solare al Museo della Civilta Romana: sinergie possibili (An Exhibition on Solar Energy at the Museum of Roman Civilization; Possible Synergies),

Seminar “I pionieri dell’energia solare incontrano le nuove generazioni (Solar energy pioneers meet new generations)”, Rome (Italy), April 4, 2008; www. gses. it 2008.

[7] C. F. Giuliani, Evidenze archeologiche e fonti storiche per la riscoperta dell’uso dell’energia solare in alcuni ambienti costruiti nell’antichita (Archeological Evidence and Historical Sources for Rediscovering Sun’s Energy Use in the Built Environment in Antiquity), Seminar “I pionieri dell’energia solare incontrano le nuove generazioni (Solar energy pioneers meet new generations)”, Rome (Italy), April 4, 2008; www. gses. it 2008.

[8] G. Vinaccia, Per la citta di domani (For the City of Tomorrow), Fratelli Palombi Editori, Volume II, Roma, 1943 — 1952.

[9] C. Silvi, The work of Italian solar energy pioneer Giovanni Francia (1911 — 1980), Proceedings ISES SWC 2005, Orlando, Florida (USA); www. gses. it 2008.

[10] Nice-Matin, L’utilization industrielle de la ‘houille d’or’ premier pas vers les (futuriste) villes del soleil, Vendredi 9 Octobre 1970.

[11] G. Francia, Solar City Project — Hypothesis for an Urban Structure, Proceedings COMPLES meeting, Marseilles, Bulletin 19, April 1971.

[12] C. Silvi, R. Torti, L. Francia, DVD ‘Giovanni Francia’s Contribution to the Idea of a Solar City’, Oct. 2006.

[13] C. Silvi, The Italian National Solar Energy History Project, Poster presentation, Proceedings of ISES Solar World Congress 2007, Bejing (China), Sept. 18-21, 2007.

E. Yandri1* N. Miura1, T. Kawashima1, T. Fujisawa1, M. Yoshinaga2

1Solar Energy Research Group, Department of Vehicle System Engineering, Faculty of Creative Engineering,
Kanagawa Institute of Technology, 243-0292 Atsugi, Japan

2Department of Architecture, Faculty of Science and Technology, Meijo University, 468-8502 Nagoya, Japan

Corresponding Author, vandri@,ctr. kanagawa-it. ac. jp
Abstract

Solar energy can be converted into electricity with Photovoltaic cells and to heat with solar collectors. Especially for solar collectors, the heat collected can be utilized for both water heating and space heating applications. Solar collector researches for space and water heating has been developed and resulted many interesting designs, from simple thermosyphon systems with low maintenance to automatic operation systems which are depended so much with mechanical and electrical properties like pumps, valves, sensors, etc. Recently, a device which transfered heat from the hot reservoir near the top to the cold reservoir at the bottom was invented by Ipposhi et. al [6], called as the ITMI model. As same as the ITMI model was constructed and tested. We improved the ITMI model by proposing the IMT model. The first report was presented in SWC 2007 by comparing the performance of ITMI model and IMT model. The current experiments are completed with a digital flow mater of vapor in order to be able to calculate the heat energy transported. Some experimental parameters are varied in order to know the optimal operating condition for this IMT model. Heat input is varied for 100, 200, and 300W. Inclination angle between evaporator and top heat storage is varied for 0, 5, and 100. Level of heat store in the top heat storage are varied for 20, 110, and 200mm. Result shows that this IMT model can work better for all heat input (100, 200, 300W), and for all heat store in the top heat (20, 110, and 220mm) with inclination angle of 00, 50, 100. This model could be more interesting for water and space heating applications as more ecological approach.

Keywords: natural circulation, thermosyphon, solar energy

1. Introduction

Solar energy can be converted into electricity by Photovoltaic cells, heat by solar collectors, and both electricity and heat by hybrid photovoltaic and thermal (PV/T) panels. The collected heat can be used for Space Heating and Solar Water Heating (SWH). A typical SWH system is a combination of solar collectors, an energy transfer system and a thermal storage system. SWHs are also characterized as open loop system (direct) which circulates potable water through the collectors and closed loop system (indirect) which uses antifreeze heat-transfer fluid such as polypropylene glycol to transfer heat from the collector to the potable water in the storage tank [2]. Depend on the way to circulate the working fluid, SWHs are divided into active system which uses a pump to circulate the working fluid such as water or polypropylene glycol through the collectors and passive system which circulates the working fluid naturally by the effect of the gravitational force [2]. The passive system calls also thermosyphon which means the heat transport device that can transport a large amount of heat using body forces (gravitational and centrifugal forces). Thermosyphon has a great advantage because of no electrical energy and simple structure. That is why, the thermosyphon researches are not intended for SWH application only, but for many applications. Thermosyphon was studied as an alternative liquid cooling technique in which heat is transferred as heat of evaporation from evaporator to condenser with relatively small temperature difference [3]. Thermosyphon radiator used for domestic and office heating was studied and its performance has been tested with Freon 11, acetone, methanol and water as working fluid [1]. A model of the two-phase flow and heat transfer in the closed loop two phase thermosyphon (CLTPT) involving co-current natural circulation, which is focus for electronics cooling that exhibit complex two-phase flow patterns due to the closed loop geometry and small tube size [4]. The main reason to develop a thermosyphon with a heat source near the top and heat sink at the bottom is to solve weight problem when a thermosyphon installed on the roof [7].

The monitored performance of a prototype STACS system mounted on a rooftop in Cardiff, Wales showed that a thermal COP of around 0.6 could be achieved in cooling mode, and that the efficiency of the evacuated tube collectors ranged between 0.7 and 0.85 depending on orientation and angle [7]. This data was used in the modelling predictions shown above, so the STACS system and component efficiencies are based on performance actually achieved using Wales weather conditions.

3. Carbon Emissions from the Welsh Housing stock

Using Table 2 and assuming all the current heating and DHW thermal demands are met from gas, and the cooling demand is met from electricity, then we can convert these demands into Carbon Dioxide equivalent emissions using the latest UK conversion factors [11]. The DEFRA guidance suggests using 0.43 kgCO2/kWh emissions factor for electricity for displaced electricity, and 0.185 kgCO2/kWh emissions factor for natural gas (gross CV). Table 3 shows the calculated annual carbon dioxide emissions figures per house type using these figures. It can be observed that the predicted annual carbon dioxide emissions are between 40 and 60 kgCO2/kWh per m2 regardless of the age or size of property.

Figure 3, derived from the data used in Ampatzi [5], shows the predicted solar yields and direct solar use in each dwelling as a percentage of the predicted dwelling annual thermal demands. It can be seen that the dwellings are capable of generating between 20 — 95% of their annual thermal demands via their collectors, but can generally only displace between 10 — 20% of these thermal demands from use of the solar energy when little or no storage is present.

Table 4, again derived from the data used in Ampatzi [5], shows the predicted carbon emission savings that could be made in the modelled dwellings through use of the tested solar thermal system and components as discussed in Agyenim [7]. Two sets of savings are shown — the first is with the direct use of Solar Thermal within the dwelling, i. e. with little or no Thermal Energy Storage (TES). The second set of savings show the potential savings achievable if sufficient TES capacity were installed to use the currently excess solar yield in each house. An overall exergy efficiency for the TES system of 40% is assumed. A further set of calculations still need to be undertaken showing the TES capacity needed to achieve various solar fractions in the houses with realistic system losses. However these two examples help to set reasonable limits to the range of carbon emission savings practically achievable within each house type.

Table 4 shows that, considering only the direct use of Solar Thermal within the dwellings, the potential reduction in the dwellings’ total carbon emissions (i. e. including electricity) range from around 4% to 11%, with 8 — 10% savings being achieved in most of the buildings. The table also shows that the use of a 40% efficient TES system could increase these savings to between 6% and 25%. As a general

observation it appears that TES could potentially double the potential carbon savings, though this would clearly depend on the design of the TES system.

The table also shows that thermal demands only constitute around 70% of the total carbon emissions from domestic properties in Wales. If we consider only these demands then Solar Thermal can potentially save around 14 — 36% of these carbon emissions.

4. Conclusions

Whilst this paper cannot provide estimates for the potential savings from the housing types not assessed in this study, the similar levels of potential percentage savings predicted for each of the house types modelled indicates that these savings levels are likely to be repeated in other house types as well.

It would seem therefore that Solar Thermal systems could potentially contribute a reduction of between 10 — 25% in the total carbon emissions from the Welsh Housing stock using only the practically useful roof areas found on each dwelling. These levels of predicted Carbon Emissions savings are significant in the context of the overall Welsh Housing stock, including existing housing, assuming that the Case Study models are a representative sample of the full stock.

The findings from House 1 also imply that even old housing stock can be brought back into energy efficient use when current energy efficiency techniques are used in its renovation (house 1 being a listed building). In conjunction with Solar Thermal techniques these savings can be very substantial.

Overall, it would appear that Solar Thermal should be strongly considered as an ingredient in Wales’ move towards a low carbon economy.

Acknowledgements

This research is supported by a grant from the Wales Energy Research Centre.

References

[1] Welsh Assembly Government, Renewable Energy Route Map for Wales, 2008. http://new. wales. gov. uk/consultation/desh/2008/renewable/routemape. pdf? lang=en

[2] Ampatzi E, Knight I — “The potential application of residential solar thermal cooling in the UK and the role of thermal energy storage technologies” — Proceedings 2nd PALENC Conference and 28th AIVC Conference, pp 48 — 53, Crete, Greece September 2007. ISBN 978-960-6746-02-4

[3] Rhodes M, Knight I, Agyenim F — “Categorising the Existing Welsh Housing Stock in Terms of Heating and Cooling Demand and Thermal Storage Capacity” — Proceedings 2nd PALENC Conference and 28th AIVC Conference, pp 818 — 824, Crete, Greece September 2007. ISBN 978-960-6746-02-4

[4] Agyenim F, Knight I, Rhodes M — “The use of phase change material (PCM) to improve the coefficient of performance of a chiller for meeting domestic cooling in Wales” — Proceedings 2nd PALENC Conference and 28th AIVC Conference, pp 1 — 5, Crete, Greece September 2007. ISBN 978-960-6746-02-4

[5] Ampatzi E, Knight I, Rhodes M, Agyenim F — “The role of thermal energy storage in helping solar thermal reduce the heating, cooling and DHW demands of the Housing Stock in a Northern European Country” — Proceedings EUROSUN 1st. International Conference on Solar Heating, Cooling and Buildings, Lisbon,

Spain October 2008

[6] Rhodes M, Agyenim F, Knight I, Ampatzi E — “Parameters Affecting the Aesthetic Integration of Solar Thermal Heating and Cooling Systems in Domestic Properties in a Northern European Country” — Proceedings EUROSUN 1st. International Conference on Solar Heating, Cooling and Buildings, Lisbon,

Spain October 2008

[7] Agyenim F, Knight I, Rhodes M, Ampatzi E — “A comparison of ‘real world’ and laboratory efficiencies for the solar collector and chiller components of a domestic solar air conditioning system” — Proceedings EUROSUN 1st. International Conference on Solar Heating, Cooling and Buildings, Lisbon, Spain October 2008

[8] Knight I, Kreutzer N, Manning M, Swinton M, Ribberink H — “Residential Cogeneration Systems:

European and Canadian Residential non-HVAC Electric and DHW Load Profiles ” — A Report of Subtask A of FC+COGEN-SIM: The Simulation of Building-Integrated Fuel Cell and Other Cogeneration Systems. Annex 42 of the International Energy Agency Energy Conservation in Buildings and Community Systems Programme. 82 pages. May 2007. © Her Majesty the Queen in Right of Canada, 2007. ISBN No.: 978-0-662­46221-7 Catalogue No.: M154-12/2007E

[9] TRNSYS, 2008 http://www. trnsys. com/ [accessed 14 June 2008].

[10] ECOTECT, 2008 http://www. ecotect. com/ [accessed 14 June 2008].

[11] DEFRA Guidelines to Defra’s Greenhouse Gas Conversion Factors for Company Reporting, June 2008 http://www. defra. gov. uk/environment/business/envrp/pdf/ghg-cf-guidelines2008.pdf and http://www. defra. gov. uk/environment/business/envrp/pdf/ghg-cf-guidelines-annexes2008.pdf [accessed 13 August 2008]

1.1 Energy dependency

Armenian’s energy sector has been integrated into united energy system of the Soviet Union and had about 3,400MW total installed capacity of generation plants including: thermal power plants of 1,600MW, nuclear power plant of 800MW and hydro power plants of about 1000MW. After the collapse of the Soviet Union, and declaring independency in 1990, the devastating earthquake and country’s blockade Armenia suffered energy crisis. Presently the country is operating about 2,000MW of production capacity with over 6 billion kWh/year electricity generation. Over 75% of electricity generation and about 100% of heat generation depends on the imported fuel (natural gas and nuclear fuel). Most of generating facilities including the nuclear power plant are out-aged. The generating sub-sector needs significant investments to modernize and build new plants to meet increasing energy demand. In 2025 the electricity generation is forecasted at about 10 billion kWh/year.

Annie Dobrinova1, Lyubov Dombeva2

Bulgarian Solar Energy Society, BgISES; 37 “Graf Ignatiev”str.; Sofia 1000, Bulgaria
E-mail: adobrinova@adiss-bg. com
2dombeva@abv. bg

Abstract

The presentation concerns to the circumstances of RESources involvement in Bulgarian school education. The traditional pattern of subjects taught in Bg schools consists no subjects relevant in RES in teaching — physics does not include it. One of the main approaches is to involve Solar Energy ideas without the existing schedule to be changed — an integrated broad teaching RES tool. An optimal classes’ result, experienced by the authors is the Art&Techniques synthesis. RES teaching, experienced in 60 Bg schools are described, analyzed and illustrated. The authors recommend partnership between teachers and RES firms, pupils and media etc. to achieve positive RES&EE broad public awareness results. Another kind partnership recommended is between Art (drawings, pantomime, etc) and pupil/teachers. One of the best results is partnership with officials from national or international institutions, which much more stimulates special RE initiatives and great number of training RES opportunities.

Key words: RES training; teaching RES;

1. Introduction

Bulgaria is among countries, where educational changes happen only with Ministry decree (edict), which means in fact — rather slowly. Most of the teachers keep the ministry’s schedule and prefer ministry recommendations for how to include any innovative ideas in their class time. The success of Solar School Forum (SSF) project (2004-2006) would be impossible if our SSF team was not lucky to win the good will of the Bg Ministry of Education. That happened after really more than 9 months exchange of official letters with them in the beginning of SSF project. So the authors think valuable to share this experience of ours — how anyway more than 60 schools were involved with Renewable Energy education in Bg.

A model of the top heat thermosyphon proposed in the present study is shown in Fig.1(a), called IMT model. The system equipped with a small reservoir of water at the end of the condenser as shown in the figure. The condenser located on the top of the system is consisted of two tubes soldered together. The flow of the mixture of the liquid and vapor in the upper tube is cooled by the lower tube in which the liquid from the cooler flows so that the vapor in the upper tube is condensed. When the volume of the vapor is increased, the total volume of the vapor and the liquid expands. It is aimed to have reservoir for storing the extra liquid at the top. The loop tubes are made from chopper. The inside and outside diameters of loop tubes are 8mm and 9.5mm, respectively, except the tubes of evaporator which have inside and outside diameters of 11mm and 12.7mm, respectively. The length of the evaporator is 620mm. The length of tube of the condenser is 1800mm. The length of the coil dipped in the cooler or water batch controller as heat exchanger is 1200mm. The length between the center of the evaporator and the center of the cooler is 1140mm. The heat input of evaporator is supplied by two ribbon heaters wich consume 250W for one heater. The power of two ribbon heaters are varied by resistors from 0 to 500W. The dimension of thickness, width, and lenght are 1mm, 20mm, and 500mm, respectively.

As shown in Fig.1(b), some temperature measurements are located around the body of the tubes. T0 is to measure the inlet temperature to the evaporator. T1 to T6 are to measure the temperature inside the

evaporator. T7 is to measure the exit temperature of water from the evaporator. T8 to T13 are to measure the temperature in the heat exchanger (condenser). TJ4 and TJ5 are to measure the inlet and outlet temperature of heat exchanger (condenser). TJ6 is to measure the temperature inside the top heat storage. T17 is to measure the temperature inside the water bacth controller (cooler). TJ8 is to measure the inlet temperature to the water batch controller. T19 is to measure the outlet temperature from the heat exchanger and the top heat storage. T2o is to measure the outlet temperature from the water batch controller. T21 is to measure the outlet temperature from the flow meter. To investigate more details the performance of this IMT model, some parameters are varied. Heat input are varied with 100, 200, and 300W, comparing with the previous report were 200 and 400W [5]. The inclination angle between the evaporator and the top heat storage are varied with 00, 50, and 100. The remained water in the top heat storage are varied with 93%, 77%, and 61%. The water batch controller keeps the temperature at 400C and one experiment takes 90 minutes and the data is collected for every 30 seconds.

a. IMT Model — experimental set up b. Temperature measurement position

Fig.1. Experimental set up and temperature measurement position for IMT Model

Table 1 shows the 14 experiments with varied parameters. There are 6 experiments for heat input 100W, which are Exp.1 (100W, 00, 93%), Exp.3 (100W, 50, 93%), Exp.6 (100W, 50, 77%), Exp.8 (100W, 100, 93%), Exp.10 (100W, 100, 77%). Exp.13 (100W, 100, 61%). There are 4 experiments for heat input 200W, which are Exp.4 (200W, 50, 93%), Exp.7 (200W, 50, 77%), Exp.11 (200W, 100, 77%), Exp.14 (200W, 100, 61%). There are 4 experiments for heat input 300W, which are Exp.2 (300W, 00, 93%), Exp.5 (300W, 50, 93%), Exp.9 (300W, 100, 93%), Exp.12 (300W, 100, 77%).

10th October, Lisbon — Portugal r

2. Result and Discussion

The performance of these experiments can be evaluate by two factors, efficiency and steady circulation. Fig.2 shows the experimental results for heat input 100W with variation of the inclination angle and the remained water in the top heat storage. There are six experiments have been done for heat input of 100W. There are two experiments which gave the higher efficiency and a steady circulation. They are Exp.3 (100W, 50, 93%) and Exp.6 (100W, 50, 77%). The other 4 experiments which gave the low efficiency and unsteady circulation are Exp.1 (100W, 00, 93%), Exp. 10 (100W, 100, 77%) and Exp.13 (100W, 100, 61%).

Fig.2. Variation of temperatures, mass flow rate, and efficiency for heat input of 100W

Fig.3 shows the experimental results for heat input of 200W with variation of the inclination angle and the remained water in the top heat storage. There are 4 experiments have been done for heat input of 200W. Exp.4 (200W, 50, 93%) and Exp.7 (200W, 50, 77%) shows a good performance with higher efficiency and steady circulation but the performance of Exp.11 (200W, 100, 77%) and Exp.14 (200W, 100, 61%) are very poor, means that lower efficiency and unsteady circulation.

Fig.3. Variation of temperatures, mass flow rate, and efficiency for heat input of 200W

Fig.4 shows the experimental results for heat input 300W with variation of the inclination angle and the remained water in the top heat storage. There are 4 experiments have been done for heat input of 300W. The performance of Exp.2 (300W, 00, 93%) and Exp.5 (300W, 50, 93%) are very poor, means that lower efficiency and unsteady circulation. Exp.9 (300W, 100, 99%) and Exp.12 (300W, 100, 77%) show good performance with higher efficiency and steady circulation.

Fig.4. Variation of temperatures, mass flow rate, and efficiency for heat input of 300W

Table 2 shows the summary of the experiments. The highest efficiency for heat input 100W is achieved by Exp.6 (68%) and the lowest efficiency is achieved by Exp.13 (-0.3%). For heat input 200W, the highest efficiency is achieved by Exp.7 (59%) and the lowest efficiency is achieved by Exp.11 (33%). The highest efficiency for heat input 300W is achieved by Exp.12 (69%) and the lowest efficiency is achieved by Exp.2 (41%). The highest overall efficiency for these experiments is achieved by Exp.12 (69%).

3. Conclusion

The performance of thermosyphon with heat source near the top and heat sink at the bottom was studied by varying the operation parameters of heat input, inclination angle, and the remained water in the hot water storage. Result shows that the inclination angle and the remained water in the top heat storage are the important parameters which can influence the performance of thermosyphon.

Acknowledgement

The support of “High-Tech Research Centre Project for Private Universities: matching fund subsidy from MEXT, 2007-2011” for this research is appreciated.

References

[1] F. F. Jebrail, M. J. Andrews, “Performance of A Heat Pipe Thermosyphon Radiator",

International Journal of Energy Research, Vol. 21, 101-112 (1997)

[2] G. L. Morrison, “Solar Water Heating”, Solar Energy edited by J. Gordon, 2001, International Solar Energy Society, p.223-289

[3] R. Khodabandeh, “Heat Transfer in The Evaporator of An Advance Two-Phase Thermosyphon Loop”, International Journal of Refrigeration 28 (2005) 190-202

[4] S. I. Haider, Y. K. Joshi, W. Nakayama, “A Natural Circulation Model of The Closed Loop, Two Phase Thermosyphon for Electronics Cooling”, Journal of Heat Transfer — October 2002, Vol. 124 / 883

[5] S. Ito, N. Miura, K. Tateishi, “Studies of A Thermosyphon System with A Heat Source Near The Top and Heat Sink at The Bottom”, Solar World Congress, Beijing, September, 2007

[6] S. Ippohshi, S. Tabara, K. Motomatu, A. Mutoh, H. Imura, “Development of A Top-Heat Mode Loop Thermosyphon”, The 6th ASME-JSME Thermal Engineering Join Conference, March 16­20, 2003

[7] Y. Maydanik, “Loop Heat Pipes-Highly Efficient Heat Transfer Devices for Systems of Sun Heat Supply”, Proceedings 1 of Eurosun 2004 Conference, 2004, p.470-47

Currently the contribution of renewable energy resource in Armenia is negligible. A number of small hydro power plants and one pilot wind power plant are under operation with less than 2% of contribution in total electricity generation. At the same time, the electricity generation potential only from small hydro and wind power plants in Armenia is estimated over 2 billion kWh/year. Having said that one should expect that contribution of small hydro power plants (with 10MW capacity and less) and wind power plants in Armenia can contribute about 20% of total electricity generation by 2025. The potential of solar energy in Armenian is significant. The average solar irradiation in Armenian is assessed at 1,760 kWh/sq. m. Thus, solar thermal energy applications can contribute in heat and hot water supply sufficiently.

1.2 Challenges renewables face with

Despite some undertakings have been taken by the government of Armenia to promote renewable energy development in Armenia since 2001, realization of renewable energy projects face with real challenges. In grid connected projects the major obstacle for private and foreign investments are tariffs which are not attractive to finance projects; this is especially true in case of wind energy. In thermal energy applications, such as solar energy, the main obstacles are subsidized natural gas prices and nuclear energy. Finally, one of the real obstacles is the lack of public awareness and proper education in renewable energy and benefits it can offer to the public and the state such as reliance on own energy resources, independency on imported fuel and international prices, environmentally friendly technologies and increased energy security. Moreover, there is a lack of familiarity in terms renewable energy, green energy and clean energy.

The results of Bg Ministry of Education’s decision to patronize the SSF project were as follow:

• an initial fax from Ministry of Education to all Bg schools recommending them to join the SSF project (December, 2004);

• attendance and open addresses to all our six SSF official events — SSF opening ceremony — SunDay04; National SSF exhibition,2005; 4 seminars, including several media attendances;

• confirmation of the importance of SSF ideas and work by the Exclusive award for two Bg schools, (each EU 100,000 for their EE reconstruction), distinguished by the Bg SSF jury;

• distinguish SSF First winners with honorary diploma for the SSF Bg National Exhibition, 2005;

Below are given the result which follow from the Ministry’ patronizing of SSF project.

Teachers, together with students succeeded to organize local Days of Energy celebration and to select 276 entries to participate in SSF Bg National exhibition (26-28 June 2004), where two Ministries, 22 Bg firms and 3 German ones offered their individual awards for Bg SSF national winners. Moreover all that happened with schools most without internet access;

Participating in local, national or international RES/EE exhibitions or competitions.

Invite Pantomime/Actors Body at school celebration with Etudes, dedicated to RES/EE/sustainable Bg reality and this way bringing laugh and pleasure across.

Most of the more experienced teachers in Bg have once weekly an hour to be with his/her class. Ministry patronizing of SSF project encouraged these teachers to dedicate this hour to the topic of environmental protection through RES/EE. Our SSF team supplied them with suitable training RES aids.

Partnership between teachers, students ( schools) and RES firms, agencies, etc.

Partnership between teachers, students ( schools) and RES experience of officials from national and international institutions;

Partnership between teachers, students ( schools) and RES issues of different media;

More detailed collaboration with existing international teams;

In the frame of official school schedule, keeping in accordance with governmental educational requirements the students could be well informed in interesting and attractive way with RES. Programs, such as “Man and Nature”, “Household and Techniques”, “Household and Economy” — allow the pupils to get skills in collecting and distributing RES information; to know objects and events, to compare them, to look for their interrelations and at the end to form own relation to the environment and its protection. *)2.

Developed different games with environmental content and results;

2. Conclusion

• Indirect study of RES could also inform pupils in global environmental problems, enough to get stable position, when graduated;

• RES skill and knowledge could serve as a good ground in further team work;

• The RES knowledge itself are not enough — the pupils need their interest to be aroused and they to be stimulated to look for solutions —

References

Dobrinova A., Shtrakov St., Marinov N., — “RES-what has it to do with you”, Proceedings, NorthSun2007, Riga, Latvia;

Eneva J., XXXVI National Conference in physics education; Physics and Energetics;

3-6 April 2008; Sofia

C. Silvi

Gruppo per la storia dell’energia solare (GSES) — Via Nemorense, 18 — 00199 Rome, Italy

E-mail: csilvi@gses. it

Abstract

This paper reviews research and organizational activities for the creation of the Italy’s Archive on the History of Solar Energy, a project started in 2003. The project’s main purpose is to preserve the Italian heritage of solar energy use, creating a digital archive accessible via the Internet. The first branch of what will be a geographically distributed archive has been taking shape over the past years at the Luigi Micheletti Foundation and the Eugenio Battisti Museum of Industry and Work (www. musil. bs. it) in Brescia, in northern Italy. An important step forward came in 2006, when the “Italian National Committee ‘The History of Solar Energy’” (CONASES), a multidisciplinary non-profit entity, was established by the Italian Ministry for Cultural Heritage and Activities, following a proposal by the Group for the History of Solar Energy (GSES, www. gses. it). In 2008, a cooperation agreement on a nationwide survey of sources on solar energy, signed between the State Archives Department and GSES, opened up new prospects for further development of the Archive. Examples of archives and documents already collected and under study are provided. The paper also shows that the Solar Archive project is already rewriting Italian solar energy history.

Keywords: solar archive, solar history, solar pioneers, solar architecture, solar cities,

1. Introduction

It often happens that we think of solar energy (its direct and indirect forms, wind, hydro, forests and other biomass) as an aspect of our modern world, although it had powered everything on earth until 150-200 years ago, when its fossilized forms — coal, oil and gas — began to gain sway.

For thousands and thousands of years the use of solar energy shaped human settlements and cities, farming and forestry, architecture and buildings, landscapes and territories, religious beliefs and cultures, social relations and lifestyles on Earth — in a word, whole civilizations. The use of solar energy is thus an age-old experience marked by milestones on the path that led human beings to artificially convert it into other useful forms of energy and goods: food, construction materials, heat, fuel, daylight and, more recently, electricity, which has been, is and will continue to be a fundamental part of modern life.

Discoveries in the field of solar energy use, made during what I would propose to call the primitive or ancient solar age — when solar was the sole source of energy — still have a major role in our daily lives. This is well exemplified by the Romans’ discovery of windowpane glass in the first century A. D., to bring daylight inside buildings and at the same time prevent cold and winds from entering. Today millions upon millions of windows provide daylight to homes and workplaces all over the world, thereby saving on artificial light produced with electricity generated by fossil and nuclear fuels.

An additional example is provided by farming and agriculture. From the earliest civilizations they were powered, and continue to be powered today, by solar energy as the primary and principal energy source.

These technologies and discoveries, which have evolved throughout the centuries, are still of greatest importance in our daily lives. It is as if an ancient renewable-solar-energy soul were an essential part of our modern world, taken for granted and not accounted for in official energy-use and economic statistics. Therefore, the history of solar energy can hold important lessons for our own times, when humanity is beset by a growing number of problems, closely related to the use and availability of energy.

Since 2000 GSES, a volunteer not-profit organization formed by experts and scholars from various technical fields, has been promoting and organizing initiatives aimed at producing a systematic history of the use of solar energy. In this paper, the focus is on modern or future solar age, currently sprouting from the pioneering work on solar energy done over the last centuries, in particular during the last 150-200 years.