This lecture presents the Energyscope energy calculator, designed to show the public different energy options and their impacts, allowing them to test hypotheses regarding nuclear energy, wind power, and fossil fuels. It also compares current energy costs with those of an energy transition, demonstrating that achieving CO2 emission goals and phasing out nuclear power is feasible and affordable. The lecture emphasizes the variety of energy solutions available, such as hydroelectricity, wind power, and photovoltaics, highlighting the importance of understanding the overall energy system. Additionally, it explores the economic impact of the energy transition, including job creation through building renovation and energy system changes, showing how the transition can drive societal development and future job opportunities.