At present, nobody knows how the energy future will look like. What is certain is that fossil resources can be depleted in the horizon of decades. Proven reserves of uranium – if the power consumption should be replaced by current reactors – would last for only a few years. There are only three promising energy technologies: nuclear fusion, fast breeder reactors with closed fuel cycle and renewable energy sources, along with energy efficiency. While commissioning of the first fusion power plant is expected the earliest by 2040, and demonstration plants with so-called generation IV reactors in 2030, renewable energy sources are already massively installed at present. Construction of nuclear power plant is always more expensive and takes more time than originally planned. Situation of renewables and especially photovoltaic is the reverse – they are built faster and the prices are lower than anyone imagined.