Optimal control of thermal energy storage for a solar energy driven refrigeration plant to cool a fruit storage facility.

Abstract

There is a growing need to adjust electricity consumption to electricity generation due to the rising share of electricity generation from solar and wind energy. Refrigerated storage can support this by thermal energy storage in e.g. an ice buffer. Aim of this study is to investigate how optimal control can help to optimize the exploitation of an ice buffer. In this study the controlled system has a number of cold rooms for fruit storage, a refrigeration plant, and an ice buffer, connected by a network of pipes in which a brine circulates. Electric energy is supplied from local PV panels, supported by the power grid. It is shown how the formation and melting of ice is adjusted to forecasted electricity tariffs. The results demonstrate how an optimally controlled ice buffer can help to shape the electric energy consumption, while maintaining temperatures in the storage rooms.