As the energy transition evolves, more fossil-driven base-load generation is being replaced with intermittent renewable energy sources. Peak power plants will continue to play a crucial role in future renewable energy systems to complement renewable energy supply. The focus of this thesis is on alternative fuels that can be utilized in conventional gas turbines. Several alternatives fuels exist, such as hydrogen, methanol and bio-fuels, and each alternative fuel has different technical, economic, social and environmental implications for the energy system and the society as a whole. Decision makers across the energy sector face difficult trade-offs between quantitative and qualitative criteria when selecting and alternative technology to invest in. This paper applies the analytical hierarchy process (AHP) to select an alternative fuel for a peak power plant in Rotterdam. The fuels analysed are methanol and hydrogen, and are ranked according to nine sub-criteria. Two contributions are proposed to improve the AHP method. Firstly, incorporating a technology readiness level indicator to quantify the technological maturity. Secondly, multiple perspectives are incorporated from key stakeholders in the criteria weighting. A sensitivity analysis is then performed on the most relevant criteria.