The invention relates to a thermoelectric-based power generation system designed to be clamped onto the outer wall of a steam pipe or other heating pipe. The system can include a number of assemblies mounted on the sides of a pipe. Each assembly can include a hot block, an array of thermoelectric modules, and a cold block system. The hot block can create a thermal channel to the hot plates of the modules. The cold block can include a heat pipe onto which fins are attached.