The current centralized energy distribution method is a vulnerability since access to energy is a requisite for the use of modern technology intensive system used within the defence. This energy dependence is further expected to increase with time. In order to decrease the risk of energy loss in the event of possible incidents and to increase the robustness in the power supply system, there are several possibilities to adopt existing energy distribution systems. In this process, there are several parameters to take into consideration when choosing energy systems. With this background, this report gathers information regarding alternative energy supply systems as a foundation for continued research about their risks.