Benefits of thermal energy storage

The use of thermal storage, coupled to a refrigeration unit, allows the user to reduce the cooling capacity of installed units, to lower operating costs and electric bills, to increase plant reliability and to provide an effective solution for investors who want to optimize their equipment.
During the 10th IIR Conference on PCMs and Slurries for Refrigeration and Air Conditioning which was held in Kobe, Japan, in August 2012, G. Duhot* stressed the benefits of thermal energy storage and presented a software tool developed by EDF-Research and Development, France, for decision support to select and design thermal storage solutions.

Currently, 3 types of thermal storage are available on the market: sensible heat storage, latent heat storage and thermochemical storage (still immature). However, the application of thermal storage on the European market is currently scarce due to many obstacles related to a lack of knowledge and design/management tools.

The use of thermal storage, coupled to a refrigeration unit, allows the user to reduce the cooling capacity of installed units, to lower operating costs and electric bills, to increase plant reliability and to provide an effective solution for investors who want to optimize their equipment.
Moreover, if well-designed, thermal storage can lead to energy efficiency improvement; when the refrigeration unit operates at night, the COP can be improved by about 10% thanks to high pressure decrease compared with a daytime operation. Furthermore, the continuous nominal operation and the reduced number of start/stop cycles allows average energy savings of about 15%.

The author also stresses the potential for thermal storage in France where refrigeration and building air conditioning in industrial and commercial sectors represent annual electricity consumption of about 20TWh.

* Cold storage: a key flexibility and energy efficiency, G. Duhot (gregoire.duhot@edf.fr)

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