This study evaluates the knowledge-based energy investments of European economies. For this purpose, a novel hybrid fuzzy decision-making model is generated to define important issues of energy technology investment and examine European countries for this situation. It is concluded that all analysis results are quite similar that shows the coherency of the findings. Nuclear safety and renewable technologies have the greatest importance to increase knowledge-based energy investments. It is also determined that Germany, France, and the UK are the most successful countries regarding the energy technology investments. European countries should first invest nuclear security technologies to use this energy more effectively. In this context, nuclear power plants working with thorium both reduce radioactive waste and eliminate the risk of nuclear explosion. Therefore, it will be much easier for European countries to solve the energy problem thanks to nuclear energy, which is fully secured. Additionally, investments in renewable energy technologies will contribute to the sustainable economic development of European countries. In this context, current developments in renewable energy technologies are actively followed. Hence, the use of renewable energy will be significantly increased, which will help economic development of the countries.