Europe is without any doubt the worldwide technological leader in solar thermal (ST) development. European companies lead mainly in the following sectors:

• Selective coatings for absorbers

• Advanced collector production methods (e. g. laser welding)

• Advanced flat-plate collector technology

• High-quality vacuum tube collectors

• Process heat collectors

• Stratified hot water storage tanks

• Electronic controllers

• System technology (e. g. solar combined systems for domestic hot water and space heating, with a burner directly integrated into the storage unit)

• Large-scale ST systems combined with seasonal heat storage

• Advanced applications (cooling, combined systems and industrial applications)

Clearly, Europe is currently leading in nearly all sectors of ST technology, which explains why the manufacturing capacity in Europe is growing enormously, notably in relatively high-wage countries, such as Austria, Germany, Denmark and the UK.

Moreover, some European countries, including Sweden, Denmark, Germany and Austria are leaders in low-energy building technology, which is a prerequisite for a high ratio of solar thermal energy in heating systems. In this area, strong cooperation with other technology platforms, such as ECTP and SusChem, is necessary.

The significant growth seen in the European market over the last decade has helped to consolidate this technological advancement. However, the current market size in Europe (around 2 GWth new installed capacity per year) is still small, compared with the current Chinese market (12.6 GWth per year) and the expected future global ST market, which could reach 100-200 GWth within a decade.

The technological perspective for the potential of solar thermal use in Europe is enormous. On the basis of comparative data on the current market development in Europe and globally, it is shown that in the short term (until 2020 at least), and with existing technologies, the solar thermal market can grow immensely without reaching the point of market saturation.

Figure 2 shows the growth in solar thermal energy use according to different scenarios. The lower graph shows the development in the case of business as usual, the middle graph shows the case of advanced market deployment, whereas the upper graph indicates the development needed to supply our energy sustainably.

Figure 3: Solar thermal contribution to the EU heat demand sector.

Figure 3 shows the contribution of solar thermal energy to the EU heat demand sector. The long-term potential of solar thermal energy is to meet around 50% of EU heat demands. In order to achieve this goal, an installed capacity of 2576 GWth or 8m2 per inhabitant would be necessary. This potential can be achieved by 2050 provided an appropriate mix of R&D efforts and market deployment measures are taken into account.

This 50% goal is only achievable, if at the same time the heat demand of our building stock is reduced by 40% (figure 3). Therefore efficient use of energy in combination with effective integration of solar energy is the important goal. For this we need new technologies, new materials and system approaches.