Session: 09-02 Pumped Thermal Energy Storage

Paper Number: 103080

103080 - Assessing the Role of High Temperature Tes in Sco2 Based Pumped Thermal Energy Storage Systems Valorising Industrial Waste Heat Recovery: A Techno-Economic Analysis 

In the current renewable energy dominated power system, as power production is becoming more and more unpredictable, it would be important to act at two levels: integrating relevant power/energy capacity of energy storage and making demand more controllable. At this purpose, acting on industrial energy demand via integration of energy storage and electrification of local processes, could be significant. Waste heat recovery (WHR) is a quite consolidated industrial energy efficiency best practice too. Nevertheless, its valorisation is usually considered for industrial processes captive uses and/or for power production via ORC or supercritical CO2 (sCO2) power cycles. The development of thermo-mechanical storages to be installed at industrial level, can contribute in this direction through the use of traditional technologies (rotating machinery) employed in power plants as well as in Waste-heat-to-power (WH2P) plants.

This paper presents a thermo-economic analysis of Pumped Thermal Energy Storages (PTES) evolving sCO₂( cycles, comparing different layouts. The proposed systems would be also capable to integrate waste heat sources, which are typically at temperatures in the 100-400°C range, difficult to exploit for WH2P solutions and rarely addressed in literature so far. In fact, the use of additional heat, otherwise dumped to ambient, can make the system capable of an apparent (electrical-to-electrical) round-trip efficiency (RTE) higher than 100%. The use of sCO2 could enhance the techno-economic features of these systems, also in terms of reduced levelized cost of storage (LCoS) and electricity (LCoE), if compared to similar plants evolving steam or air or organic fluids. At the same time, the valorisation of low temperature waste heat can enable industries to enhance their energy efficiency, limit their operational costs and environmental impact, whilst becoming an active part in the regulation of the grid. At this purpose optimal system configurations and dispatch strategies are identified based on typical load curves and considering various EU and US electricity markets

The goal of the paper is also to present the relevant role of TES in this type of PTES plants. Different TES systems and materials, at different temperature levels (related to the different PTES operating conditions), will be studied and presented together with the possibility to integrate low to mid temperature TES to stabilize the WH input.

Starting from an identified reference case (a cement production plant with WH temperature to be valorised around 350°C),  layouts and TES will be compared via different KPIs such as the levelized cost of storage (LCoS), Capital (CAPEX) and the operational (OPEX) costs. Technological readiness, scalability and sizing criteria of the proposed layout and TES are presented highlighting the suitability of different technical solutions for small and large scale industrial sites.

 

 

 

Presenting Author: Simone Maccarini Università degli Studi di Genova

Presenting Author Biography: Simone Maccarini is a PhD Student at University of Genova, Thermochemical Power Group, developing R&D related to modelling advance energy systems with a focus on those ones envisaging turbomachinery operating with sCO2.

Authors:

Syed Safeer Mehdi Shamsi Università degli Studi di Genova
Simone Maccarini Università degli Studi di Genova
Silvia Trevisan KTH
Stefano Barberis University of Genova
Rafael Eduardo Guedez Mata KTH