The main conceptual design requirements of the RICAS2020 research infrastructure were specified in Work Package WP2 Design Requirements and Feasibility Study. Design alternatives were proofed in relation to the associated costs and the current and future strategic relevance & feasibility. The concepts are oriented to a realization of the research infrastructure as a 5 MW prototype.
In WP3 Concept and Engineering Plans for Thermal Energy Storage a quasi-one-dimensional heat transfer model to predict the thermodynamics of TES systems was developed and validated by ETH. Three groups of high-temperature materials (rocks, concrete, and ceramics) were considered and based on a thermodynamic and environmental analysis, the ideal storage material are rocks from the excavation site.
In WP4 numerical simulations were performed with a focus on the development of a new breakthrough realistic simulation approach. This approach allows overcoming limitations of the existing tunnel excavation simulation procedure in ABAQUS, namely, stress-free installation of the support elements with an intact thickness.
The aim of WP5 Concept for Innovative (Cavern) Excavation Methods was to develop an innovative tunnelling technology to be used in the construction of the large air storage caverns that will be needed for an Advanced Adiabatic Compressed Air Energy Storage power plant (AA-CAES). Initial studies on the efficiency of laser ablation under various external conditions showed that the specific energies required make the removal of rock material via melting and vaporisation bye laser irradiation unfeasible and uneconomical. From observations of these initial studies concepts combining laser ablation and mechanical cutting were developed.
WP6 Concept for New and Advanced Materials contains an evaluation of the initial location requirement as well as the possible lining material and structural solution. For the RICAS2020 project, the most promising design for the storage is represented by a segmented liner solution with internal polymeric based sprayable membrane.
In WP7 Safety and Security Assessment Concept information on relevant CAES projects, as well as other underground gas storage installations, namely CO2 and natural gas storage was worked out. Furthermore the corresponding norms and regulations for CAES, CO2, and natural gas storage are described. The safety aspects of underground gas storage are also investigated through two case studies. They provide information on the long term aspects of an underground gas storage facility.The safety aspects of the test facility were analyzed, according to the standard ISO 31 000.
In WP8 an environmental analysis of RICAS2020 concept has been performed to determine the hotspots for the whole life cycle, from the resources obtaining, the construction until the operation. To do the analysis, the life cycle inventory data related to each compartment of RICAS concept (excavation process, TES infrastructure, cavern construction, machinery and operation) has been created.Furthermore a detailed social analysis of RICAS2020 has been done.
WP9 ensured that the dissemination and exploitation activities were successfully performed. A RICAS2020 project website (www.ricas2020.eu) was launched at the beginning of the project. Dissemination activities like presentations, publications and press articles have been carried out. Furthermore discussions with funding bodies and the Austrian ministry took place to foster the realization of the RICAS2020 research infrastructure as follow-up of this design study. Further important activities of dissemination were the creation of a project video and a project flyer, as well as the organisation of RICAS conferences and workshops.
