A data-driven merit order: Learning a fundamental electricity price model

Abstract: Power prices can be forecasted using data-driven models or fundamental models. Data-driven models learn from historical patterns, while fundamental models simulate electricity markets. Traditionally, fundamental models have been too computationally demanding to allow for intrinsic parameter estimation or frequent updates, which are essential for short-term forecasting. In this paper, we propose a novel data-driven fundamental model that combines the strengths of both approaches. We estimate the parameters of a fully fundamental merit order model using historical data, similar to how data-driven models work. This removes the need for fixed technical parameters or expert assumptions, allowing most parameters to be calibrated directly to observations. The model is efficient enough for quick parameter estimation and forecast generation. We apply it to forecast German day-ahead electricity prices and demonstrate that it outperforms both classical fundamental and purely data-driven models. The hybrid model effectively captures price volatility and sequential price clusters, which are becoming increasingly important with the expansion of renewable energy sources. It also provides valuable insights, such as fuel switches, marginal power plant contributions, estimated parameters, dispatched plants, and power generation.