In 2030 the electricity production in the isolated power system of the Faroe Islands, will be 100% renewable, if the set vision is met. Moreover, both the heating and transport sectors will be 100% electrified. This means that the installed renewable generation will be increased significantly. The generation from new wind farms and solar plants will have to replace the electricity currently generated by fossil fuelled generators. However, these inverter-based technologies typically lack the capability to participate in stabilising the system frequency during a power deficit. This means, that if no alternative initiatives are taken, the 6 existing hydro power plants will be the only units regulating the frequency. This paper studies the frequency behaviour in today’s system and in 2030, and analyses whether the hydro power plants will be enough to regulate the frequency, or if alternative initiatives are a necessity. The two power systems have been simulated under normal conditions, with a sudden load decrease and with a line outage. According to the simulation results the frequency will worsen in 2030 compared to today, but it will still stay within today’s frequency thresholds. The simulation results of today’s system also show a significantly better response than the actual grid frequency. The greatest variations in the simulations of today’s system under normal conditions are 30 mHz, while the actual grid frequency typically varies between 49.5 Hz and 50.5 Hz. The model built for this study is a simplified and aggregated version with generic governors, and thus, it is concluded that the model should be developed further, in order to retrieve more realistic results from the simulations.