Predictability and flexibility are key enablers to increase CSP penetration in the energy mix by a) increasing dispatchability b) making CSP less/not reliant on subsidies c) supporting stable grid operation d) enabling operators to access new revenue streams (electricity trading, ancillary services). Today CSP plants with molten salt storage only partly achieve these objectives. Key enabling technologies to be demonstrated and introduced in the market are 1) design and operation of molten salt once-through steam generator – This will allow fully flexible plant operation; 2) design and implementation of integrated weather forecasting and dispatch optimization – This will allow optimal management of the energy storage to maximize revenues while respecting constraints/commitments (e.g. to the grid). Towards 1), an innovative design approach is proposed, integrating process and equipment design with dynamic simulation of the system. Proven technologies in separate fields (molten salt ; once-through steam generator ; optimum control) will be for the first time integrated and demonstrated. Towards 2), different approaches to DNI forecasting (direct; mesoscale models) will be integrated to extend geographical coverage and improve reliability. Dispatch optimization under conditions of uncertainty (weather forecast) and perturbations (e.g. grid support requests) will be developed. Furthermore, automatic plant performance characterization by machine learning will be implemented to ensure a real optimum is achieved. For succesfull market introduction, a down-scale pilot will be realized. Here, integrated operation of once-through steam generator, weather forecast and dispatch optimization will be demonstrated. CSP will undergo large growth in developing markets, where grid constraints and market liberalization will play a role. Developint these key-enabling technologies will put european industries in the position to compete at the forefront in the market worldwide.

The RESLAG project proposal is aligned with the challenges outlined in the call WASTE-1-2014: Moving towards a circular economy through industrial symbiosis. In 2010, the European steel industry generated, as waste, about 21.8 Mt of steel slag. The 76 % of the slag was recycled in applications such as aggregates for construction or road materials, but these sectors were unable to absorb the total amount of produced slag. The remaining 24 % was landfilled (2.9 Mt) or self-stored (2.3 Mt). The landfilled slag represents a severe environmental problem. The main aim of RESLAG is to prove that there are industrial sectors able to make an effective use of the 2.9 Mt/y of landfilled slag, if properly supported by the right technologies. In making this prof, the RESLAG project will also prove that there are other very important environmental benefits coming from an “active” use of the slag in industrial processes, as CO2 saving (up to 970 kt/y from CSP applications, at least 71 kg/ton of produced steel from heat recovery applications), and elimination of negative impacts associated with mining (from the recovery of valuable metals and from the production of ceramic materials). To achieve this ambitious goal four large-scale demonstrations to recycle steel slag are considered: Extraction of non-ferrous high added metals; TES for heat recovery applications; TES to increase dispatchability of the CSP plant electricity; Production of innovative refractory ceramic compounds. Overall, the RESLAG project aims at an innovative organizational steel by-products management model able to reach high levels of resource and energy efficiency, which considers a cascade of upgrading processes and a life cycle perspective. All these demonstrations will be lead by the industries involved in the RESLAG consortium. The RESLAG project is supported by the main organizations representing energy-intensive industries, CSP sector, energy platforms, governments, etc.