This Small Business Innovation Research (SBIR) Phase II project proposes the development of river energy harvesters uniquely suited to harvesting energy from undammed turbulent river flows, currently untapped due to state-of-the-art technology limitations. Mature renewable energy technologies include silicon based solar panels, large scale wind turbines, and high-head hydropower turbines. However, consumers are often geographically distant from these resources. The vast majority of people live adjacent to life-sustaining waterways. Millions live in remote parts of the world alongside vast hydrokinetic resources, but currently have little or no access to reliable electricity. This program specifically seeks to address such underserved markets. Recently, there has been growing interest in harvesting from flows with significant kinetic energy, which have been described in a US resource assessment study as a "gargantuan" untapped natural resource. But with existing technology, siting continues to be the single biggest challenge facing expansion of this high-energy renewable resource. This project aims to develop harvesters specifically suited to turbulent and/or very low head flows, thereby expanding hydro-energy siting options and potentially enabling a second hydro-power boom.<br/><br/>The Phase II technical effort will explore the conversion of hydrokinetic energy to mechanical energy via a dynamic, fluid-solid interaction. An example of the phenomenon to be harnessed is the bouncing motion observed in power lines on rainy, windy days. The repeating motion is observed only during specific weather conditions because the unstable dynamics are a function of both the flow type, and the geometry of the affected surface. This motion is undesirable in most instances, including for power lines, but it also represents an energy conversion opportunity from ill-behaved flows. The Phase I project identified and demonstrated two specific adaptive structures strategies for enhancing the desired energy conversion; additional strategies were identified and will be investigated during a Phase II project. The goal of this Phase II program is to demonstrate technical and commercial feasibility of the resulting technology by building and operating a 2 kilowatt prototype in the field.