Electricity market outcomes, specifically prices and volumes, are significantly influenced by infrastructures. In Italy, electricity market zones have unique features due to interconnection levels, energy mixes, and consumption patterns, especially Sicily and Sardinia with their limited mainland connections. Sicilian prices were studied thanks to the possibility to work on a relatively isolated environment (Sapio and Spagnolo, 2016), also focussing on renewables that play a big role in specific areas (Sapio 2015). The 2016 completion of the Sorgente-Rizziconi cable enhanced the link between Sicily and the mainland, affecting day-ahead prices. This work examines the impact of grid innovations on the volatility of zonal electricity prices in Sicily by analysing day-ahead prices and their structural components. In a wide sense, it also forecasts the effects of future grid developments on the Sardinian and Sicilian markets. Studying these island markets is crucial to understand how infrastructure affects price volatility. These findings can potentially be generalized to other markets with suitable adaptations.