SolSteam - Innovative integration concepts for solar-fossil hybrid process steam generation

Abstract

Within the 6th Energy Research Program, the German Government aims at a significant reduction of the primary energy consumption and 60% of the country’s energy shall be provided by renewable energy sources by 2050, see [1]. The process heat sector represents a considerable part of the total energy consumption. Heat within the temperature range between 100 °C and 400 °C was identified as the target market for concentrated solar applications. The Solsteam project aims at the development of a solar-hybrid steam generating system for industrial process heat, see [1]. In cooperation with the DLR (German Aerospace Center) that has a long-time experience in concentrated solar power, the system shall be developed that consists of a gas-fired steam boiler of the German Company Viessmann GmbH and a Fresnel Collector of the company Industrial Solar, Freiburg, Germany, both specialists in their field. In the present paper various possible integration solutions are discussed. Three concepts have been identified as promising and are therefore described in detail. The preliminary assumptions for input parameters do not allow a final decision for one of the three concepts. However, a techno-economic evaluation of one exemplary system has been carried out for three typical sites in Europe: Freiburg, Rome, and Antalya. The size of the solar field has been optimized individually taking into account common profitability criteria for projects. As expected, the optimum of the solar field size depends on boundary conditions, such as irradiation and subsidies on the investment.