Energy supply process from energy producers to energy consumers consists of several stages, where each stage is very important because the whole process provides main exercise and goal – secure and reliable energy supply for the consumers. In last years, increasing the damages in the power systems not only from the technical point of view but from physical intervention as well, including external hazardous – terroristic attack, the actual question is critical energy infrastructure protection and evaluation of risks of critical infrastructure damages and outages. European Commission identified goals and guidelines for definitions of critical elements of power system infrastructure and provided measures for such infrastructure protection. In whole Europe energy supply companies start to include in development plants also the probability of critical infrastructure outages, to forecast risks not only for internal faults, but for external outages as well, and start plan measures of power system restoration, taking into account external interventions to the power system. Both electricity and gas sectors in the energy field in many countries in Europe are strongly interdependent because the part of the electrical energy is produced by CHPs, operated by gas. Security of energy supply, risks, and synergy of different types of infrastructure are analyzed also in Baltic countries and Latvia as well. The methodology of energy infrastructure faults impact evaluation, based on the network topology, generation specification and hazards probability in Latvia is proposed in the paper and could be implemented in future in the energy sector.