Techno-Economic Assessment of Residential Heat Pump Integrated with Thermal Energy Storage

Abstract

Phase change material (PCM)-based thermal energy storage (TES) can provide energy and cost savings and peak demand reduction benefits for grid-interactive residential buildings. Researchers established that these benefits vary greatly depending on the PCM phase change temperature (PCT), total TES storage capacity, system configuration and location and climate of the building. In this study, preliminary techno-economic performance is reported for a novel heat pump (HP)-integrated TES system using an idealized approach. A simplified HP-TES was modeled for 1 year of space heating and cooling loads for a residential building in three different climates in the United States. The vapor compression system of the HP was modified to integrate with TES, and all heat transfer to and from the TES was mediated by the HP. A single PCM was used for heating and cooling, and the PCT and TES capacity were varied to observe their effects on the building’s energy consumption, peak load shifting and cost savings. The maximum reduction in electric consumption, utility cost and peak electric demand were achieved at a PCT of 30 °C for New York City and 20 °C for Houston and Birmingham. Peak energy consumption in Houston, New York City, and Birmingham was reduced by 47%, 53%, and 70%, respectively, by shifting peak load using a time-of-use utility schedule. TES with 170 MJ storage capacity allowed for maximum demand shift from on-peak to off-peak hours, with diminishing returns once the TES capacity equaled the daily building thermal loads experienced during the most extreme ambient conditions.

Shell Shape Influence on Latent Heat Thermal Energy Storage Performance during Melting and Solidification

“…One promising technology that allows for compact yet high-capacity energy storage, with a high energy density, involves the simultaneous utilisation of sensible heat and latent heat through a solid-liquid phase change. Phase-change materials (PCMs) have various applications across industries, including automotive battery temperature management systems [1], spacecraft thermal control [2], temperature stabilisation systems in buildings [3,4], electronic equipment, pharmaceuticals, and food industries [5]. The main advantage of PCMs lies in their ability to store a large amount of energy within a narrow temperature range.…”