1. SOLAR THERMAL M. Santamouris

2. CONTENTS a) Today Situation b) Progress Achieved c) Tomorrow Priorities

3. TODAY SITUATION - Increase of the Energy Demand - Most Buildings in Urban Areas (80%)

4. improved living standards low conventional energy prices non sufficient energy legislation TODAY SITUATION Increase of the Energy Demand

5. increase of the gross domestic product 19701993 DK,FR,IT, GR, SP, PT improved living standards

6. Improving living standards, increases the space requirements per person. It is characteristic that in the United States, between 1950 and 1990, the floor space requirements per person has been doubled. Very important differences in housing floor space per person exist also in Europe because of the social and economic differences. Moscow has 11.6 m2 net living space per person, while Paris has 28.2, Oslo 47.2 and Zurich 50.6 m2 per person.

7. improved living standards 19801990 increase space per inhabitant 2 2.5 3 3.5 persons per household GR,IT,PT,SP,FR,DK,

8. improved living standards RAPID PENETRATION OF AIR CONDITIONING The impact of air conditioners usage on electricity demand is a serious problem for southern European countries. Peak electricity loads oblige utilities to build additional power plants in order to satisfy the demand, thus increasing the average cost of electricity. This situation has become a serious problem for many countries. In USA, the total electric peak load induced by air conditioning is estimated equal to 38 percent of the non coincident peak load.

9. 1990199119921993199419951996 improved living standards A/C SALES

10. NON SUFFICIENT STANDARDS U Value for outer walls 0.68 1.2 0.9 UK 0.45 NL 0.4 D 0.5 F 0.28 DK 0.3 B 0.6 A 0.5

11. NON SUFFICIENT STANDARDS Energy Demand of a Model House (kWh/m3/a) 22.6 26.1 24.9 28.9 20.0 UK 22 NL 20 D 21 F 28.1 DK 13.3 B 32 A 25.3

12. PROGRESS ACHIEVED - Development of Retrofitting Techniques - Development of Passive Cooling Techniques - Development of Advanced Components - Development of Evaluation Methods Development of Testing Methods

13. Development of Retrofitting Techniques Development of Retrofitting Techniques Recent research permits to use new methodologies to incorporate solar energy in retrofitted of buildings and improve indoor environment. Main priorities regarding appropriate energy retrofitting are : - The full knowledge of the existing and available energy conservation technology. - The use of the developed methodologies to evaluate from the technical and economical point of view, the possible retrofitting scenarios.

14. Development of Passive Cooling Techniques Development of Passive Cooling Techniques New Developments on Natural Ventilation, Solar Control, Use of Natural Sinks, while new hybrid components have been developed.

15. Development of Advanced Solar Components New Intelligent components integrating passive solar heating, cooling and daylight features have been developed. Advanced control strategies and systems have also been developed.

16. Development of Evaluation Methods Extremely accurate prediction tools as well as simplified models for designers have been developed. Existing tools cover the major part of the existing systems and techniques.

17. Development of Testing Methods Development of Testing Methods Finally Testing Methodologies for Solar Components have been developed.

18. FUTURE PRIORITIES FUTURE PRIORITIES The problem of energy and global environmental quality of buildings is complicated and should not been seen as isolated phenomena. On the contrary it has to be studied in relation to the problems of indoor and ambient environmental quality.

19. FUTURE PRIORITIES FUTURE PRIORITIES ΆRGY AND QUALITY IN THE URBAN ENVIRONMENT 70 % of the energy consumption of buildings is spend in urban environment. In particular the thermal and optical phenomena as well as the air quality in the urban environment determine, almost completely, the energy consumption as well as comfort and quality conditions in buildings.

20. FUTURE PRIORITIES FUTURE PRIORITIES TECHNIQUES TO BETTER INTEGRATE SOLAR Recent technological developments on the field of solar energy in buildings including passive heating and cooling techniques as well as daylight systems, permit to seriously decrease the energy consumption, improve thermal and visual conditions in buildings as well its indoor air quality. However, there is a lack of knowledge on the optimum integration of these techniques in urban buildings

21. FUTURE PRIORITIES FUTURE PRIORITIES TECHNIQUES TO BETTER INTEGRATE SOLAR Application of passive solar systems and techniques and in particular of the cooling techniques while are well known and scientifically comprehensible under undisturbed conditions, present important problems when have to be used in cities and incorporated in urban buildings. mainly because of : a) The dramatic variation of the energy potential of the sources and sinks, (i.e.. air movement).b) The restrictions because of the urban limit conditions. c) The particular climatic phenomena, (I.e. pollution).

22. FUTURE PRIORITIES FUTURE PRIORITIES ΆRGY RETROFITTING OF BUILDINGS Energy spend by new constructions is less than 1 % of the total energy consumption of the buildingís sector. Problems of high energy consumption and not appropriate indoor air quality are mainly presented in old and medium age existing buildings of specific characteristics.

23. FUTURE PRIORITIES FUTURE PRIORITIES ΆRGY RETROFITTING OF BUILDINGS concrete knowledge of the specific energy consumption of each building sector as well as of the specific energy targets by type of building. There is a need for a more concrete knowledge of the specific energy consumption of each building sector as well as of the specific energy targets by type of building.

24. FUTURE PRIORITIES FUTURE PRIORITIES ΆRGY RETROFITTING OF BUILDINGS There is a need to further develop appropriate methodologies to evaluate from the technical and economical point of view, the possible retrofitting scenarios of urban buildings as well as a need to develop labeling methodologies

25. FUTURE PRIORITIES FUTURE PRIORITIES SOLUTIONS TO DECREASE THE PENETRATION OF A/C A European frame program to investigate and develop solutions to decrease the rapid penetration of air conditioning is absolutely necessary