This experimental study investigates the piezoelectric energy-harvesting performance of composite laminated shell structures for energy-harvesting applications. Thin-walled composite shells were fabricated using hand layup with Glass Fibre Reinforced Polymer (GFRP) composites, and PZT patches were placed on the shell surface. The effective orthotropic material properties of the laminated shell were initially estimated using the Rule of Mixtures to predict the modal characteristics of the GFRP shell. Experimental tests were conducted using an electrodynamic shaker under sinusoidal base excitation at 30 Hz, with the thin composite shell structure mounted at its centre. The electromechanical response was characterized by simultaneously measuring the central transverse displacement of the shell and the voltage outputs from the two surface-bonded Macro Fiber Composite (MFC) transducers. Results demonstrate bounded oscillations of the composite laminated shell, with a peak-to-peak central displacement of approximately 1.60 mm and corresponding voltage outputs of 3.68 and 3.44 V from the two MFC transducers. The composite shell configuration achieved a wideband frequency response with superior broadband harvesting characteristics. The experimental validation confirms that composite laminated shell piezoelectric energy harvesters offer broadband performance suitable for powering wireless sensor networks, IoT devices, and structural health monitoring systems in large vibrating structures operating at low frequencies.