Forecasting Spot Price Volatility Using the Short-Term Forward Curve

This paper uses high-frequency real-time spot prices and day-ahead forward prices from the eastern hub of the Pennsylvania-New Jersey-Maryland (PJM) electricity market to calculate, describe, and forecast realized spot price volatility. Using Heterogeneous Autoregressive models of realized volatility (HAR-RV) we find that, as in financial markets, electricity volatility is persistent. We extend the literature by incorporating volatility implied by day-ahead forward prices (forward implied volatility) into our forecasts of future spot price volatility. Including forward implied volatility improves forecasts of spot price volatility - in the sense of higher R-squareds and lower forecast errors