Mustafa presented his work which increases the renewable energy power plant integration on electrification systems and scenario analysis for Turkey and its islands at the 15th SDEWES conference held online. Turkey currently depends mostly on conventional thermal sources mainly lignite and natural gas. Hydropower has 23% in the total electricity generation and other renewables 22%. In the Energy Trilemma Index, Turkey is Rank 44 place, scoring highly in the energy equity and environmental sustainability dimensions, but lower in terms of energy security. Turkey is planning to diversify energy mix, adding more nuclear, solar, wind and hydro. This study analyses the impact of high penetration of renewable energy sources in meeting the rapidly growing demand. The techno-economic characteristics of centralised generating plants in all 4 regions (mainland (81 cities nodes) and 3 islands regions (11 islands nodes)) are modelled, with national high voltage transmission grids and demand load aggregated at regional control centres in each region. A model using PLEXOS has been developed to simulate short-term loads with intermittent renewables and its flexibility within different scenarios. It was found that integrating renewable energy, particularly solar and wind (especially offshore), in the mainland and islands power grid would have a positive impact on installed capacity and electricity generation. Ultimately, the integration of high renewable energy in the island interconnected grid would provide more sustainable electricity and aid the progression of Turkey in energy trilemma index. It was determined that an additional electricity capacity from renewable power plants in region 1,2 and 3 of 82 MW, 31 MW and 2 MW respectively is needed in the 2030 RE scenario to achieve environmental agenda. In addition, a 7.5 GW in Turkey mainland is needed. In the BaU scenario to support energy security 4.8 GW installed capacity nuclear power plant is needed. A 20% increase in renewable energy installed capacity for the 2030 RE Scenario shows improvement in terms of energy security.