The classic boost topology is a good choice for photovoltaics (PV) Maximum Power Point Tracking (MPPT) converters as it has small current ripple on the input. The efficiency is key parameter for PV-sources as it significantly influences solar system total payoff time. As the energy efficiency for classic converters with silicon-based switches is limited by today technology the GaN switches are chosen. The paper contains brief introduction and market research to set the initial tasks for design. The paper contains simulation results on prototype of boost MPPT converter. All the elements being used for model are device models provided by manufacturers. During the research expected efficiency curves are obtained. Design have been modeled with different GaN switch types for better FET choice. The model will be compared to the real prototype in future research.