  Growth in the penetration of renewable energy sources makes supply more
uncertain and leads to an increase in the system imbalance. This trend,
together with the single imbalance pricing, opens an opportunity for balance
responsible parties (BRPs) to perform energy arbitrage in the imbalance
settlement mechanism. To this end, we propose a battery control framework based
on distributional reinforcement learning (DRL). Our proposed control framework
takes a risk-sensitive perspective, allowing BRPs to adjust their risk
preferences: we aim to optimize a weighted sum of the arbitrage profit and a
risk measure while constraining the daily number of cycles for the battery. We
assess the performance of our proposed control framework using the Belgian
imbalance prices of 2022 and compare two state-of-the-art RL methods, deep Q
learning and soft actor-critic. Results reveal that the distributional soft
actor-critic method can outperform other methods. Moreover, we note that our
fully risk-averse agent appropriately learns to hedge against the risk related
to the unknown imbalance price by (dis)charging the battery only when the agent
is more certain about the price.
