energies Review Thermal Energy Storage for Grid Applications: Current Status and Emerging Trends Diana Enescu 1,2,* , Gianfranco Chicco 3 , Radu Porumb 2,4 and George Seritan 2,5 1 Electronics Telecommunications and Energy Department, University Valahia of Targoviste, 130004 Targoviste, Romania 2 Wing Computer Group srl, 077042 Bucharest, Romania;
[email protected] (R.P.);
[email protected] (G.S.) 3 Dipartimento Energia “Galileo Ferraris”, Politecnico di Torino, 10129 Torino, Italy;
[email protected] 4 Power Engineering Systems Department, University Politehnica of Bucharest, 060042 Bucharest, Romania 5 Department of Measurements, Electrical Devices and Static Converters, University Politehnica of Bucharest, 060042 Bucharest, Romania * Correspondence:
[email protected] Received: 31 December 2019; Accepted: 8 January 2020; Published: 10 January 2020 Abstract: Thermal energy systems (TES) contribute to the on-going process that leads to higher integration among different energy systems, with the aim of reaching a cleaner, more flexible and sustainable use of the energy resources. This paper reviews the current literature that refers to the development and exploitation of TES-based solutions in systems connected to the electrical grid. These solutions facilitate the energy system integration to get additional flexibility for energy management, enable better use of variable renewable energy sources (RES), and contribute to the modernisation of the energy system infrastructures, the enhancement of the grid operation practices that include energy shifting, and the provision of cost-effective grid services. This paper offers a complementary view with respect to other reviews that deal with energy storage technologies, materials for TES applications, TES for buildings, and contributions of electrical energy storage for grid applications.