Energy, Vol.138, 419-436, 2017
Performance and cost evaluation of an innovative Pumped Thermal Electricity Storage power system
Wind and solar energy have a time dependent nature which is their main disadvantage. To overcome this drawback, energy storage systems need to be set up. High-temperature Pumped Thermal Electricity Storage employing packed bed as storage medium can be an attractive solution. For this reason, in the present paper, firstly, an in-depth literature review on Pumped Thermal Electricity Storage and on storage materials is presented with the aim of assessing the current state of the art. Then, a new Pumped Thermal Electricity Storage configuration is proposed and tested. An electric heater is used to convert electrical energy into thermal energy, a single heat exchanger is installed and air is used as heat transfer fluid. A 1D packed bed model is used to simulate the thermal performance of the hot and cold storage. In the storage model also the pressure drop is taken into account. The plant mathematical model is implemented in Matlab environment while the heat transfer fluid and bed material properties are taken from CoolProp and NIST database, respectively. An energy and cost analysis is performed in order to assess the feasibility of the system. Five types of high storage density material, two bed material shapes and different maximum plant temperature are tested and their influence on the technical and economic characteristics and performance of the plant is assessed. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords:Pumped Thermal Electricity Storage;PTES;Electricity storage;Energy analysis;Economic analysis;Numerical modelling