Improving CHP flexibility by integrating thermal energy storage and power-to-heat technologies into the energy system

Smart energy grids include smart thermal and electrical grids. One of the links between them is the combined heat and power (CHP) plant, which supplies both heat and power to the grid. CHPs are designed for stable heat and electric loads and their ability to cope with peaks and lows needs to be improved. This paper explores technical solutions aimed at improving CHP flexibility, considering the potential transition to the 4th generation district heating (4GDH). CHP flexibility extends its operating time and improves the energy efficiency of the system. The solutions examined include coupling CHPs with electric boilers and TES, which will help balance heat and power loads and allow to introduce RES to the system. In this study, these technical solutions are compared in terms of natural gas consumption, heat rejection reduction, and the share of heat supplied to the system by the CHP. The results of this study show that when 150 000 m3 TES and 40 MW electric boiler are integrated into the Tallinn DH system, natural gas consumption can be reduced by 36% and heat rejection by 38%. & COPY; 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).