This article discusses the prospects for the use of power units based on renewable energy sources for additional and emergency power supply of surface robotic systems. This kind of complex power unit can be built on the basis of renewable wind and solar energy and generate at least 10-15% of all the electrical energy required for a vessel. Considered one of the main problems of designing this type of complex power unit - the creation of a promising wind power systems (windmills). The windmill under development should meet a number of necessary criteria regarding reliability, power, noise level, and design constraints of the surface platform itself. The rationale for the design of the windmill is given. Further, the design of the windmill is optimized by the criteria of aerodynamic power, taking into account these limitations. The aerodynamic comparison shows the superiority of the proposed design of a windmill in relation to analogues on all the most important quality criteria. The features of the implementation of the electrical connection scheme of a windmill, solar panels and a diesel generator set into a single complex power unit are considered. For a robotized ship with a given power of the propulsion system, the complex power unit has been developed, which allows generating at least 10% of the power consumption.