In mitigating the effects of climate change, the global community has begun a sustainable energy transition to curtail anthropogenic emissions- with Small Island Developing States (SIDS) being slow to adapt. Trinidad and Tobago is one such SIDS located in the southern Caribbean, endowed with hydrocarbon resources supporting an active petrochemical sector; which consumes over 50% of electricity generated by outdated, low-efficiency, simple-cycle (SC) gas-based technologies. Our study utilizes techno-economic and environmental assessments to investigate how improved resource and energy efficient power generation can be achieved. Twenty (20) cases were explored, reflecting SC and combined-cycle (CC) operations, renewable energy (RE) penetration and electrification of the petrochemical sector through power-to-X systems. Our results indicate a shift towards greater energy efficiency (50%) and reduced gas utilization (7.2 GJ/MWh reduction) through CC over SC systems, with RE penetration further increasing efficiencies. Furthermore, LCA results fully support a hybrid CC-RE transition, achieving the greatest reduction (55.4%) in CO2 emissions. While power-to-X cases show consolidated environmental benefits through avoided emissions, it is associated with substantially higher costs. Thus, CC systems offer reduced environmental and economic burdens-with RE deployment further supporting sustainable operations and active decarbonization of the local power sector.