Metallic nanostructures have recently gained considerable attention owing to high energy conversion efficiency resulting from the localized-surface plasmon resonance (LSPR) phenomenon at the nanoscale. Although extensive research has focused on laser therapy applications in medicine, the potential of such nanostructures in solar energy systems remains insufficiently explored, even though their capability for significantly enhancing energy conversion efficiency is evident. Therefore, the present study investigates the influence of two types of gold nanostructures: (1) gold nanorods with a size of 46 nm and a length of 102 nm, and (2) gold nanoshells with a 45@30 nm, both characterized by Transmission Electron Microscopy (TEM) and spectroscopy measurement whose absorption maxima are located in the visible range. The nanostructures were irradiated for 25 minutes using three different light sources: (a) a conventional LED lamp, (b) a warm-white LED light source with maximum color temperature orange (CTO), and (c) a 0.8 W red laser. A comparable rate of heat flux was applied to selected system configurations to evaluate optimal thermal-insulation conditions for various substrate materials, including white PETG, optical glass, transparent epoxy resin, PA6 aluminum alloy, and hard rubber. The results from a thermal camera and resistant thermometers demonstrated that the highest enhancement rate was achieved under red-laser irradiation. However, the greatest temperature increase (ΔT) was observed for the LED lamp illumination, exceeding 100 oC after a few minutes, and surpassing the boiling point of water thereby. From an economic perspective, although the implementation of gold nanostructures requires higher financial investment, these nanostructures considerably improve the rate of energy conversion, intensifying heat transfer in the considered systems, which represents a promising strategy for improving the currently used solar thermal collectors and heat exchangers.