The terrestrial solar radiations are in the wavelength range of 0.25 to 2.5 μm [1]. This solar energy is used separately in photovoltaics and in thermal systems. In photovoltaics, the photon with higher or lower energy than the band gap of PV material remains unused and causes losses in the PV systems. The response range of C-Si solar cell is 0.75–۱٫۱۲۵ μm wavelength of the incident solar spectrum [2]. The photons with higher energy than the materials’ band gap, causes Thermalization losses in the solar cell. The output voltage of the C-Si solar cell reduces by 2.3 mV/°C temperature rise of the solar cell [3]. Thus, it is always desirable to keep the low operating temperature of the PV cells in the module. To address this issue, different techniques have been proposed in the past. Many of these studies include combined photovoltaic thermal systems (PVT), where the PV module is allowed to expose the entire solar spectrum, and heat from the PV module is extracted by means of circulating fluids, thereby improving the electrical performance of the system. Also, the collected heat is used in separate applications. Many researchers explored the PVT systems with the use of air [4–۶], water [7–۹], a combination of air and water [10–۱۲]. The exhaustive review of such several techniques has been reported in the literature [13–۱۵]. Spectrum filtration is another technique of PVT system. In this technique the solar spectrum is filtered using optical filters. The desirable part of the spectrum is allowed to fall on the PV module and the undesirable part is collected and used separately as heat. These systems are referred as beam split PVT system (BSPVT) in the subsequent text. This concept is suggested in 1955 [16]. The first experimental work of this concept is reported in 1978 [17]. The comprehensive summary of the experimental and theoretical work of such systems carried out by many researchers is documented in the recent review papers [18, 19]. The optically selective liquids with good heat capacities can be used for BSPVT. Since a decade, use of liquids for spectrum filtration for PVT applications is being explored by some researchers around the world. Use of nanofluids [20], water [21–۲۳], therminol and heat transfer oils [24] for BSPVT systems are reported in the recent past. The present research work is focused upon the investigation of easily available and inexpensive liquid for spectrum filtration suitable for BSPVT.