Lesson learned during the designing and construction phases of the ORC-PLUS thermal energy storage system of 20 MWh

A limitation to the expansion of medium sized Concentrating Solar Power (CSP) plants is represented by the lack of technical solutions of Thermal Energy Storage (TES) systems specialized for this size of CSP plants and validated in a relevant industrial environment. In order to make the medium sized CSP systems more competitive than PV systems, the TES system has to allow the operators of the solar power plant to adjust the electricity production for matching consumer demand, so enabling the sale of electricity during peak demand periods for boosting plant revenues. At the same time, there is the need of lowering the TES system weight in the capital costs of the overall system. The ORC-PLUS (Organic Rankine Cycle - Prototype Link to Storage Unit) Project aims to realize a demonstrator of a TES system optimized for a medium sized CSP plant coupled with an ORC (Organic Rankine Cycle) turbine of 1 MWe. In this paper, the difficulties encountered during the manufacturing and commissioning operations of the TES system and their potential impact on capital costs will be reported.