SOLAR THERMAL M. Santamouris. CONTENTS a) Today Situation b) Progress Achieved c) Tomorrow Priorities.

SOLAR THERMAL M. Santamouris

CONTENTS

a) Today Situationb) Progress Achievedc) Tomorrow Priorities

TODAY SITUATION

- Increase of the Energy Demand- Most Buildings in Urban Areas (80%)

improved living standards

low conventional energy prices

non sufficient energy legislation

TODAY SITUATION

Increase of the Energy Demand

increase of the gross domestic product

1970 1993

DK, FR, IT, GR, SP, PT

improved living standardsimproved living standards

improved living standardsimproved living standards

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.

improved living standardsimproved living standards

1980 1990

increase space per inhabitant

2

2.5

3

3.5

persons per household

GR, IT, PT, SP, FR, DK,

improved living standardsimproved living standards

RAPID PENETRATION OF AIR RAPID PENETRATION OF AIR CONDITIONINGCONDITIONING

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.

GREECE 76000 144000 214000 296000 412000 555000 693000

ITALY 100000 215000 365000 520000 750000 1110000 1473000

SPAIN* 205000 342000 512000 722000 972000

PORTUGAL 101054 121092 154997 183207 212557 243537 267157

1990 1991 1992 1993 1994 1995 1996

improved living standardsimproved living standards

A/C SALES

NON SUFFICIENT STANDARDSNON SUFFICIENT STANDARDS

U Value for outer walls

0.68

1.2

0.9

UK0.45

NL0.4

D0.5

F0.28

DK0.3

B0.6

A0.5

NON SUFFICIENT STANDARDSNON SUFFICIENT STANDARDS

Energy Demand of a Model House (kWh/m3/a)

22.6

26.1

24.9

28.9

20.0

UK22

NL20

D21

F28.1

DK13.3

B32

A25.3

PROGRESS ACHIEVED

- Development of Retrofitting Techniques- Development of Passive Cooling Techniques

- Development of Advanced Components- Development of Evaluation Methods

Development of Testing Methods

Development of Retrofitting TechniquesDevelopment 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 .

Development of Passive Cooling TechniquesDevelopment of Passive Cooling Techniques

New Developments on Natural Ventilation, Solar Control, Use of Natural Sinks, while new hybrid

components have been developed.

Development of Advanced Solar ComponentsDevelopment 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.

Development of Evaluation MethodsDevelopment 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.

Development of Testing Methods Development of Testing Methods

Finally Testing Methodologies for Solar Components have been

developed .

FUTURE PRIORITIESFUTURE 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.

FUTURE PRIORITIESFUTURE PRIORITIES

≈Ά≈RGY 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.

FUTURE PRIORITIESFUTURE 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

FUTURE PRIORITIESFUTURE 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).

FUTURE PRIORITIESFUTURE PRIORITIES

≈Ά≈RGY 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.

FUTURE PRIORITIESFUTURE PRIORITIES

≈Ά≈RGY RETROFITTING OF BUILDINGS

There is a need for a more concrete concrete knowledge of the specific energy knowledge of the specific energy

consumption of each building sector as consumption of each building sector as well as of the specific energy targets by well as of the specific energy targets by

type of building. type of building.

FUTURE PRIORITIESFUTURE PRIORITIES

≈Ά≈RGY 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

FUTURE PRIORITIESFUTURE 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