System integration

Following the procedure recommended as a result from IEA Task 33/IV, each potential application for solar process heat systems should initially be analysed to identify the potential for technological optimization of the production process and it’s unit operations, including the potential for heat recovery [2]. Such analysis helps to avoid over-dimensioning of the solar system, and to identify the appropriate temperature level for the integration of solar heat into the process. Since collector efficiencies are strongly temperature dependent, this information is important for the selection of appropriate solar technology and operating temperature of the system. Other important factors are the daily, weekly and annual demand profiles. These, together with the related solar resource data are needed to determine heat storage requirements and the potential solar share. In any case, the design and integration of the solar system needs to take into account that the production has the absolute priority, and the processes must not be impaired by changes in insolation or any other influences from the solar system. On the other hand, it should be endeavoured to utilize as much as possible all energy collected by the solar field.

Since the purpose of this project is the demonstration of direct steam generation in parabolic trough collectors, the solar technology is already pre-determined. Under these conditions, there are three principal options for the integration of the solar steam:

• Solar augmentation of the drying process

• Direct solar steam supply to individual consumers in the new production line

• Solar steam integration into the existing distribution