Electrical Thermal Energy Storage (ETES) System Demonstration, Modeling and Testing

Abstract

Over the years, the world has invested huge amounts of money in renewable technologies development and renewables have become an important part of energy planning. Drastic reduction in cost, especially in solar photovoltaic (PV), and increased deployment and usage of renewables, has increased the share of intermittent renewable energy in the total energy mix leading to grid management issues. This has pushed for the development and rise of new and innovative energy storage technologies. Therefore, this thesis work will focus on studying and analyzing a renewable energy system integrated with an innovative high-temperature electrical thermal energy storage (ETES) system using a metal alloy-based phase change material (PCM), which is capable of providing power distribution on demand, proposed by a Swedish company called Azelio AB. The data collected from a pilot project in Sweden was used to analyze and assess the system's performance. Based on the data collected, the total system efficiency obtained was 20%. However, this pilot was not used to full potential, and the commercial versions are likely to have an increased yield, not only due to their operating conditions, but also to incremental modifications. In addition, when comparing the initial energy for preheating the PCM to the total energy output, it was concluded that approximately 5.5 charge cycles (6 days) are needed to breakeven with the energy initially inputted into the system. Hence, this system is not suitable for short-term storage durations and is best suited for long-term energy storage applications. Moreover, a software called System Modeler was used to model the entire system. The modeling results were used to study the performance of the system and assess potential modifications needed to further improve the overall system performance. To gain a comprehensive understanding of the system operation throughout the year, two cases were simulated: summer and winter. After modifications an almost constant baseload power was achieved for both cases, where for summer we obtained a power of 38 kW and for winter we obtained a total power of 25 kW. As a result, this system proves to be a promising energy storage solution that can be integrated with renewable energy systems, especially for modular mini and off-grid systems.

Date of Award	Dec 2021
Original language	American English