Distinguishing the energy and non-energy actions in balancing energy markets

In the European context, balancing energy markets are established to optimise transmission system operator balancing actions closer to real-time. These actions aim to match total generation and consumption subject to a suite of security constraints (e.g., reserve requirements). However, there is no clear border between those actions that are taken due to the reserve requirements (non-energy actions) and those that are primarily taken to supply the demand mismatches (energy actions). To recognise the effect of non-energy actions, existing methods require comparing the results of counterfactual optimisation problems in which the non-energy-action-related constraints were deliberately omitted. This paper proposes a one-off solution enabling TSOs to distinguish energy actions from non-energy ones in the balancing market scheduling problem. By decomposition of the dual variables and clustering the constraints as proposed in this paper, there is no need to solve repetitive counterfactual optimisation problems. Case studies show that in addition to the non-energy actions caused by non-energy-based balancing requirements, the proposed method is able to recognise the energy actions that should be taken due to the non-energy root causes. This feature enables TSOs to efficiently retrace the effect of non-energy actions on the energy-based dispatch instructions issued according to the balancing market schedule.