Small island systems are exemplary candidates for testing energy system decarbonization strategies. The planning of energy sectors within these systems should be approached in an integrated and flexible manner to facilitate the transition to 100% renewable energy penetration. Due to their isolated nature, energy systems in remote islands offer a controlled environment for studying the complexities of renewable energy integration, sector coupling, and grid flexibility. La Gomera, part of the Canary Islands, stands out as a particularly strategic case study due to its ongoing transition away from fossil fuels and the planned interconnection with the Tenerife grid. In contrast to mainland Spain’s diversified energy mix, the Canary Islands remain heavily reliant on imported fossil fuels, highlighting the necessity of local, system-integrated energy planning.