Day-Ahead Electricity Price Forecasting for Volatile Markets Using Foundation Models with Regularization Strategy
Kritchanat Ponyuenyong, Pengyu Tu, Jia Wei Tan, Wei Soon Cheong, Jamie Ng Suat Ling, Lianlian Jiang
TL;DR
The paper addresses day-ahead electricity price forecasting in volatile markets, where spikes and nonlinear dynamics hinder traditional models. It proposes a spike-regularization framework STL-KF and evaluates a broad set of Time Series Foundation Models (TSFMs) against ARIMA, LSTM, CNN-LSTM, and PatchTST using Singapore half-hourly data with exogenous weather and calendar features. Results show TSFMs consistently outperform baselines, with TTMs in multivariate fine-tuning delivering the best accuracy and regularization further boosting robustness. The work provides practical guidance for deploying TSFMs in high-volatility EPF settings and suggests directions for extending the approach to other markets and probabilistic forecasting.
Abstract
Electricity price forecasting (EPF) is essential for energy markets stakeholders (e.g. grid operators, energy traders, policymakers) but remains challenging due to the inherent volatility and nonlinearity of price signals. Traditional statistical and deep learning (DL) models often struggle to capture complex temporal dependencies and integrate heterogeneous data effectively. While time series foundation models (TSFMs) have shown strong performance in general time series forecasting tasks, such as traffic forecasting and weather forecasting. However, their effectiveness in day-ahead EPF, particularly in volatile markets, remains underexplored. This paper presents a spike regularization strategy and evaluates a wide range of TSFMs, including Tiny Time Mixers (TTMs), MOIRAI, MOMENT, and TimesFM, against traditional statistical and DL models such as Autoregressive Integrated Moving Average (ARIMA), Long-short Term Memory (LSTM), and Convolutional Neural Network - LSTM (CNN-LSTM) using half-hourly wholesale market data with volatile trends in Singapore. Exogenous factors (e.g. weather and calendar variables) are also incorporated into models where applicable. Results demonstrate that TSFMs consistently outperform traditional approaches, achieving up to 37.4% improvement in MAPE across various evaluation settings. The findings offer practical guidance for improving forecast accuracy and decision-making in volatile electricity markets.
