Solar industrial process heat plants in operation
Data gathered in the framework of the IEA Task 33/IV include comprehensive information about the geographical distribution of the solar thermal plants, the industrial sectors addressed, the specific processes, the process temperatures, the solar thermal collectors technologies, the capacity installed, the type of back-up systems and some economics. This survey include the majority of the worldwide built examples with few exceptions such as China and Japan. At the present time data collection comprises 19 countries. Plants in operation in Austria, Greece, Spain, Germany, Italy and the USA represent about 75% of the total installed capacity reported.
Currently about 90 operating solar thermal plants for process heat are reported worldwide, with a total capacity of about 25 MWth (35,000 m2). The size of SHIP plants varies from small (around 10 kWth) to large scale installations over 800 kWth.
The majority of the SHIP plants operate in the sectors of food, wine and beverages, car washing facilities, metal treatments, textile and the chemical industries. Examples in food processing sectors (especially dairies) are particularly numerous: i. e. 20 plants corresponding to 23% of the sample. Wineries account for 4 of the 8 examples reported within the beverages sector, showing a large potential for future applications especially bottle washing and cooling of wine cellars.
Figure 2. Solar industrial process heat plant for a brewery in Austria (Source: AEE Intec) |
Solar car washing facilities are concentrated in Germany and Austria (8 examples), while dairies in Greece and in Italy (6 examples). 10 solar facade integrated systems are in operation in Austria for space heating of factory buildings, while in Spain the most recent solar thermal applications are mainly in the food (e. g. olives, meat and fish processing) and transport equipment sectors (e. g. washing facilities for lorries and containers).
Solar heat is mainly used at 20-90 °C for process hot water, preheating of boiler feed-water and space heating (and cooling). Therefore standard selective flat plate collectors (FPC), working in the temperature range of 30-90 °С, result to be the most installed.
Cost figures, available for about 50% of the plants analysed, range from 450 to 1,100 €/kWth with few exceptions and some differences at national level. These costs refer to plants built before 2006, while cost figures for more recent plants are not available. In Austria and Spain, the investment cost (plant size < 350 kWth) is in the range between 470 and 700 €/kWth, while costs collected for Germany and Italy in average are higher. Costs for Greek plants are lower because of some targeted marketing strategies adopted in the 90ies by the solar thermal companies. Most of the reported plants benefited of public contributions between 30% and 50% of the total cost.