Solar Energy Perspectives - IEA

Chapter 5: Industry and transport
industries, the textile and chemical industries and for simple cleaning processes (e.g. car
washes, as on Photo 5.1) where simple collectors can provide the desired 50°C to 90°C
temperature. In some cases a number of uses are combined: the Hammerer transport
company in Austria uses solar hot water to clean transport containers as well as for space
heating of its offices.
Photo 5.1 Solar water heaters can be used in service areas
Source: AEE INTEC.
Key point
Stationary solar thermal collectors provide low-temperature process heat.
Cleaning is a process that occurs in many forms. Cleaning of bottles, cans, kegs and process
equipment is the most energy-consuming part in the food industry. Metal treatment plants
(e.g. galvanizing, anodizing and painting) have cleaning processes for parts and surfaces. The
textile industry and laundries clean fabrics; service stations clean cars. All of them need warm
water at temperatures below 100°C and even below 60°C, so they provide an excellent
application for solar thermal energy. Storage and the integration into the existing heat supply
system is rather easy in these cases since very often storage tanks already exist and water is
the main medium.
Most of the washing processes require subsequent drying, which is also very energy
intensive. Although the drying medium will be warm air in general, it can be heated up
through water/air – heat exchangers. Preheating with solar heat might be a viable option
in that case. Solar air collectors represent another option, which has been particularly
developed in India for crop drying, food processing and textile manufacturing sectors
(Photo 5.2). Crop drying is an effective alternative to cooling for conservation, particularly
in a country where large quantities of crops are lost through lack of conservation
techniques.
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