The Government of Romania was in the process of delivering an Energy Strategy Plan for the country for the period 2016 -2050, developing a range of energy policy options and pathways to deal with the key challenges for energy security, competitiveness of energy markets, environmental protection to prevent climate change and energy prices accessibility. In order to efficiently combine and develop the optimum mix of energy policies to be included in the Energy Strategy Plan, the Government of Romania requested numerically sophisticated estimates on the way the energy sector evolved in the long term, complying with European Union main energy policies, and the way these actions in the energy sector interacted with the Government’s policies to enable economic growth. In this project the required quantitative modelling provided the decision makers a quantitatively detailed set of possible alternative policy options, and the way these options could be more effectively could be combined, in order to comply with Energy Union’s main objectives but also enabling national energy policies to promote the objectives of the Romanian Government. The time period covered for this study was 2016-2050, with yearly basis analysis for the period 2016-2030, and on 5-years basis for the period 2030-2050.