Status of the Development of a New High Temperature Thermal Energy Storage System (HTTESS) for CSP-power Plants

Abstract

Thermal Energy Storage-Systems (TES-System or TESS) are already acknowledged to be highly needed to optimize the electricity yield of CSP-power plants and to improve the economics of CSP-projects and to reduce electricity prices. Furthermore for many electricity grid operators it is important to have spinning reserves in the grid and dispatchable power available.It has been the task of enolcon to develop a new TES-System realizing a step change which is by its principle simple, robust with regard to execution and operation, and which is reducing the electricity costs of CSP-power plants. Furthermore such system shall be open to future developments of CSP-systems with regard to increasing steam temperatures and steam pressure. Such TES-system shall be commercially available for large scale application already in year 2014/2015.As a result enolcon has invented in year 2010/2011 a TES-System using ambient air as heat transfer fluid and stones/rock as storage medium. The key elements of the enolcon-TES are the open cycle using always ambient air with an air-air-heat exchanger and the arrangement of the storage material in such way to minimize the pressure losses and the own electricity consumption. The development is progressing in a structured way by studies, engineering works, TES-pilot plants, isothermal air flow test plant for the verification of the CFD-calculations, and since end of 2012 by the operation of a high temperature TES- module with all features of the large scale modules. The actual status of the TESS-development and the key results of the charging and discharging of the high temperature TES-module TESS002 is presented following.