The high density of water has been an important factor for harnessing kinetic energy from marine current flows, tides, flowing rivers, or other artificial water channels. Thus, new technologies are being developed to generate electricity. A good example is HKES (hydrokinetic energy systems), which are devices that extract and convert energy from the motion of flowing water into electricity. Although these non-polluting machines and/or devices are still in their pilot phases, they have been growing as a sustainable source of new electric power generation. In this paper, the performance of a horizontal hydrokinetic energy system with variable-pitch blades using an axial-flux generator is evaluated. Particularly, very simple sheet blades have been used to keep system cost down. The evaluation is based on maximum power extraction and energy conversion efficiency normalized by system cost through a simpler electro-mechanical design for the hydrokinetic system. Experimental results have demonstrated that the proposed prototype possesses higher efficiency with reduced energy losses and manufacturing costs. It represents a cost-competitive alternative energy for power supply for civilian applications in remote areas or an option for expeditionary applications.