Many island nations are vulnerable to climate change and reliant on costly fossil fuels, creating economic pressures. Renewable energy pathways are feasible and economically viable on islands, but research gaps remain. Studies highlight pathways for islands to achieve carbon neutrality by 2050 through high electrification and rapid renewable energy adoption. Solar PV dominates electricity generation in tropical islands, with offshore technologies providing a scalable pathway to a sustainable energy future. Wave power enhances energy system diversity and complements solar PV and wind power generation. The concept of a Solar-to-X Economy in tropical islands, where low-cost solar PV electricity is used to produce e-fuels, e-chemicals, and e-materials, enables deep defossilization of hard-to-abate sectors. Importing e-fuels can play a key role in cost-effective renewable energy systems on islands like the Caribbean and the Maldives. Integrating solar PV-driven solutions within a Solar-to-X Economy provides environmental and economic benefits, with key elements for defossilization including low-cost renewable electricity, energy storage, electrification, e-fuel imports, sector coupling, and grid interconnections. Power-to-X technologies are crucial for achieving carbon neutrality, energy security, and economic growth in island nations, with solar energy being a key focus in research at LUT University.