Solar Heating Worldwide

Summary

This study was prepared within the framework of the Solar Heating and Cooling Programme (SHC) of the International Energy Agency (IEA). The goal of the study was to document the collector areas previously installed in the important markets worldwide, and to ascertain the contribution of solar plants to the supply of energy and the CO2 emissions avoided as a result of operating these plants. The collectors documented are unglazed collectors, glazed flat-plate and vacuum tube collectors with water as the energy carrier as well as glazed and unglazed air collectors.

The data was collected within the framework of a questionnaire survey of the national delegates of the Executive Committee of the SHC Programme and other national experts active in the field of solar thermal energy. Since some of the 26 countries included in this study have very detailed statistics and others could only provide estimates from experts, the data was checked for its plausibility on the basis of various publications, and if necessary, corrected. Starting with the collector area installed, the contributions of solar plants towards the supply of energy and reduction of CO2 were ascertained.

The 26 countries included in this study represent 3.3 billion people which is about 50% of the world´s population. The collector area installed in these countries is estimated to represent 85-90% of the solar thermal market worldwide.

The most important results

The installed collector area in the 26 countries represented in this study equaled around 100 million square meters at the end of year 2001. Of this, 27.7 million square meters were accounted for by unglazed plastic collectors, which are used mainly to heat swimming pools, and 71.3 million square meters of flat-plate and evacuated tube collectors, which are used to prepare hot water and for space heating. Air collectors were installed to an extent of 1.6 million square meters. These are used for drying agricultural products and to a lesser extent for space heating of houses and production halls.

Total collector area by economic region

If one observes the use of solar thermal energy it becomes clear that it greatly varies in the different countries respective economic regions. In North America (USA and Canada) swimming pool heating is dominant with 23.4 million square meters of unglazed plastic collectors while in China (32.0 million square meters), Europe (11.2 million square meters) and Japan (12.1 million square meters) plants with flat-plate and evacuated tube collectors mainly used to prepare hot water and for space heating are dominant.

Leading countries - flat-plate and evacuated tube collectors

Focusing on the total of flat-plate and evacuated tube collectors installed by the year 2001, then Israel, Greece and Austria are leading with 608 m², 298 m², 220 m² per 1000 inhabitants respectively. They are followed by Turkey, Japan, Australia, Denmark and Germany with collector areas between 118 and 45 m² per 1000 inhabitants.

Leading countries - unglazed plastic collectors

With regard to the heating of swimming pools with unglazed plastic collectors, Australia leads with 103 m² ahead of the USA with 81 m² and Austria with 72 m² per 1000 inhabitants. In fourth to sixth place there are Switzerland, Canada, and the Netherlands with collector areas between 28 and 10 m² per 1000 inhabitants.

Market development

Analyzing the market development from 2000 to 2001 in the field of plants for the preparation of hot water and space heating it can be seen that the market of flat plate and evacuated tube collectors grew from 8.9 million square meters in the year 2000 to 11.3 million square meters in the year 2001. This corresponds to a remarkable growth of 26%. The most dynamic markets worldwide are in China and Europe. In 2001 the installed flat-plate and evacuated tube collectors per 1000 inhabitants was 6.4 m² in China and 3.9 m² in Europe whereas in Japan only 2.5 m² and in the USA and Canada just 0.08 m² were installed.

The market of unglazed collectors for swimming pool heating recorded also an increase from 1.3 million square meters in the year 2000 to 1.6 million square meters in the year 2001. This corresponds to a growth of 23%. The markets that underwent the greatest growth in this sector between 2000 and 2001 included the USA, Spain and France.

Contribution of solar collectors to the supply of energy

The annual collector yield of all solar thermal systems1 installed by the end of 2001 in the 26 recorded countries is 41,795 GWh (150,463 TJ). This corresponds to an oil equivalent of 6.7 billion liter and an annual avoidance of 18.2 million tons of CO2.