Integrating thermal properties and degradation modelling of batteries into the scheduling of hybrid power plants with photovoltaics

Abstract

Renewable energy penetration in the energy mix has risen sharply in the last decade, and brought with it an increased deployment of large-capacity storage systems. The result is a need for optimised management strategies that integrate and safely operate the whole energy production chain, including precise models for each element that they control. This paper presents the results of a study on detailed state-of-charge, thermal and degradation modelling of Battery Energy Storage Systems for hybrid photovoltaic-battery power plants. The objective is to quantify the error associated with not taking into account a precise model for these parameters in industrial applications. The use case of optimal battery scheduling in a capacity firming framework and a low-voltage grid is considered to quantify the impact of these models. The proposed models for these parameters were developed and then validated against experimental measures from five hybrid power plants. The models were then applied to calculate optimal battery schedules, and showed lower than expected state-of-health loss values. The impact of including the thermal modelling in the scheduling process was also observed to be weaker than expected.