Heat stands in addition to electricity for a considerable part of the industrial energy demand. Concentrating solar collectors are able to cover this demand with temperatures up to 400 °C, or even higher with new heat transfer media.
In industrial plants the heat consuming processes, for example drying processes , are in general supplied with saturated steam by a common pipe system. The solar produced steam can be immediately fed from the solar field to the existing steam system with the appropriate pressure. In addition to direct steam generation in the solar field, also the use of pressurise d water or oil as heat transfer medium is possible.
The provision of solar heat at temperature levels between 60 °C and 200 °C and above have already been successfully demonstrated in several projects with parabolic trough as well as Fresnel collectors. Direct steam generation and provision of saturated steam at 143 °C have been shown in the project “P3 – Pilot plant for solar process steam generation with parabolic trough collectors”.
Several tests, in which operation and control strategy of the system had been investigated, preceded the implementation of the solar field. These tests were performed at the test facility for Solar Process Heat Systems (SOPRAN) located at the DLR in Cologne as well as at the DISS test facility at the Spanish Plataforma Solar de Almería (owned and operated by the Spanish Research Facility CIEMAT).
Process heat systems often use quite small solar collectors comprising receivers without vacuum isolation. Furthermore, aluminum reflectors replace glass mirrors which are commonly used in solar power plants. Their advantages are the modularity and the low installation costs. The collectors are not only to be used by industrial consumers but also by the service sector, for instance large hotels. The solar research at DLR supports the producers of process heat collectors in the development and determines the efficiency according to the ISO 9806 standard.