# Possibilities of Powering Military Equipment Based on Renewable Energy Sources
## 2 Literature Review
### Solar Electricity Generator  
In case of the BES block, it is worth noting that the photovoltaic panels already generate the direct current. However, in some implementations this requires the use of a DC/DC converter system in order to obtain the current with the desired parameters. Here as well, in the BES block, the MPPT module is implemented. It uses the latest technology when it comes to the control of electromechanical systems [36]. The DC/DC converter in this block has the functionality extended by:  
1. CC charging control (i.e., preventing loopback from batteries to photovoltaic panels modules). 2. Automatic shutdown of the block if the voltage level from the panels is too high or too low. 3. Automatic restart after returning to the appropriate operating parameters, protection against short-circuit or overload, etc. 4. Electricity accumulation block. The level of reliability and efficiency of the hybrid electricity generator is largely defined by the operational reliability of BAE (i.e., the unit responsible for storing the generated BWE and BSE energy). Among the various electricity storage devices, batteries are the most widely used, so the correct selection of them is crucial. Therefore, it should be clearly pointed out which type of battery should be selected for military purposes, such as lithium-ion battery, lead-acid battery, solid-state battery, etc. The batteries must be able to handle the peak power needed during the operation of the entire generator and provide sufficient power at a nominal load for the time assumed for the device [24; 33]. At the same time, it is worth noting that they are probably the most important part that should be taken into account when considering the mobility of the entire system due to the fact that a specific feature of even the latest solutions in this field is their heavy weight and considerable dimensions. An interesting analysis of this problem has been presented in [33]. In the BDE electricity distribution block, the key parts are:  
1. A DC/AC converter, also called the inverter, converting direct current into alternating current (230 V, 50 Hz in Europe), which is acceptable to receivers. Such a system should also include functionalities related to protection against a generator overload, unfavorable loopback during energy consumption and automation systems responding to improper current-voltage parameters of the supplied electricity. 2. A set of AC and DC sockets for distribution of electricity generated by the system. Electricity generators are installations called solar-wind mobile power plants, solar-wind power mobile generators, and solar-wind portable generators, available in versions that enable the production and storage of electricity from about 1 up to 100 kW power. When used in an area with adequate sunlight and proper air movement characteristics, they are able to provide electricity 24 h a day, 7 days a week. This is the result of the authors' direct observations during land forces exercises at command posts. Often, these installations are equipped with various systems for remote control and component control via extensive computer networks. They do not require direct supervision, which significantly increases their functionality and applicability. Among the devices of this type available on the market, you can find both sets of autonomous solutions offered with parts ensuring mobility, as well as modular installations consisting of ready-made components that enable the generation and storage of electricity from both wind and sunlight. These can be adapted to one's own needs and for possibilities offered by the range of displacement of the entire hybrid system. Among the large comprehensive solutions, one of the most interesting is the German offer [35] presenting a product called Solarcontainer. It is a wind-solar container power plant equipped with an autonomous optimization system of power generation and a remote monitoring and control system for its operation.