The integration of CNG and green hydrogen as supplementary fuels in diesel engines presents a significant opportunity to enhance the sustainability of power generation, particularly in electric generator power plants. This study investigates the dual-fuel operation of diesel engines using a blend of CNG and green hydrogen, focusing on the performance metrics and environmental impacts. Quantitative findings show that replacing up to 40% of diesel with CNG and hydrogen leads to a 30% reduction in CO2 emissions, a 25% reduction in particulate matter (PM) emissions, and up to a 15% decrease in nitrogen oxides (NOx) compared to diesel-only engines. Additionally, hydrogen's zero-carbon combustion contributes to a 40% reduction in overall greenhouse gas (GHG) emissions, when the hydrogen is produced through renewable electrolysis. Efficiency improvements of up to 10% were recorded, largely due to hydrogen's high flame speed, which enables faster and more complete combustion. Despite challenges such as hydrogen storage, distribution infrastructure, and engine modifications, the dual-fuel approach retains the operational flexibility of conventional diesel generators while offering significant environmental advantages. Power plant adopting this approach is the Karaganda power plant in Kazakhstan, where a CNG-hydrogen-diesel blend has been tested in diesel generator units. This pilot project reported a 20% improvement in fuel efficiency and a 35% reduction in carbon emissions, proving the commercial viability of this technology in industrial-scale power generation. Furthermore, in regions like Germany, where green hydrogen production is becoming more widespread, similar applications are emerging as part of broader strategies to decarbonize energy systems.