Excess thermal energy is available in the industry in vast quantities, for instance in the form of exhaust gas at temperatures above 350 ºC (ca.1 TWh/yr in Norway). However, the availability of the excess heat does not often coincide with the demand. In such cases, integrated thermal energy storage systems are an effective solution to extract excess thermal energy from a process, store it for a given time and yield back thermal energy at a later moment through a passive heat transfer process.
The focus of PCM-Eff is on latent heat storage, based on heat absorption or release when a storage material undergoes a phase change, usually from solid to liquid. The phase change is generally isothermal and yields high energy storage density. Materials exploited for these purposes are called Phase Change Materials (PCM). PCM can store 5–14 times more thermal energy per unit volume than usual sensible storage materials such as masonry or rock. Though PCM materials are well documented in the literature, their implementation is still limited due to the complexity of designing suitable interfaces between PCM, heat source and heat sink.
Three strategic applications, identified with high potential for PCM implementation, are investigated in PCM-Eff:
- Cooling storage in refrigeration equipment,
- Thermal energy storage for biomass-based residential heating appliances,
- High-temperature thermal energy storage in industrial processes.
Results from this project shall generate innovative industrial solutions to improve overall energy efficiency of thermal processes, while being reliable, durable and with low associated operation costs.
PCM-Eff is a strategic competence-building project supported by SINTEF Energy Research.