Intermittent electricity (solar and wind) needs to be equilibrated with resilient supply. Fuel demand can be partially replaced by electric cars, heat pumps, and electrical equipment. How much additional electricity will be required? How much green fuel will be needed? How much electricity for green fuel production? How to build an equilibrated electricity grid and fuel supply? These are difficult questions! Every country has its electricity generation and fuel market share that is affected by climate, persons purchasing power, technology costs, local taxes, natural resources, industrialization, etc. A quick move to renewables requires an evaluation of how the different technologies can contribute. Efficiency is the right move! High-efficiency solutions reduce the demand and consumption, accelerating the move to renewables while requiring lower infrastructure. Using the best solution for each application is the challenge. Engine CHP can reduce up to 40% CO2 emission when compared with the best available technology of centralized thermal plants, fuel boilers, and air conditioning equipment. If fueled by green fuels no CO2 emissions are achieved. High-efficiency engine CHP requires a high-efficiency engine, well-designed heat exchangers, and an absorption chiller. Annual energy loads and simulation are also important – savings prediction. COGMCI is an engine CHP simulation software with more than 20 years of development. Detailed part-load performance analysis of the integrated engine CHP system is developed (engine, heat exchangers, HRSG, absorption chiller, etc). As engine CHP is an energy-saving technology, depending on the thermal loads, oversized systems can save more energy (less CO2) than engines sized for the site base electrical load. Engine CHP should be designed and sized to attend site thermal loads – annual analysis. Engine flexibility can contribute to a stabilized grid exporting electricity at low renewables production hours or operating as a demand response system. An 8760 hours case study will be presented.