Reply to the ‘Comment on “Giant pyroelectric energy harvesting and a negative electrocaloric effect in multilayered nanostructures”’ by X. Chen, V. Shvartsman, D. C. Lupascu and Q. M. Zhang, Energy Environ. Sci., 2021, DOI: 10.1039/D0EE02548H

Chen et al. (2020) used schematics to claim that a temperature-dependent change in polarisation could not lead to a change in polar entropy of single and polycrystalline materials and hence should not be used for estimating electrocaloric effect (ECE) performance using Maxwell relations. Through this article, we explain how this reasoning does not fit well to our ECE estimates for PbZr0.53Ti0.47O3 (PZT) and CoFe2O4 (CFO) heterostructures in Vats et al. (2016). In addition, a detailed explanation of the calculation of ECE performance in our heterostructures is presented since Chen et al. (2020) reported difficulty in understanding how ECE calculations in particular temperature ranges, that were away from the highest ECE temperature, were related to the polarisation versus temperature data.